Welcome to the Microscopic World of Liz Sockett

This site is designed to introduce my research interests in bacterial flagella and my work in the field of Public Understanding of Science. The site also has some useful links for science education, and information on work carried out explaining science to students with visual impairments.As an academic I've tutored and supervised many talented and entertaining undergraduates over the years. On this site there is a 'Where are they now?' page to let past students keep in touch. Check it out and E.mail me if you're a past student who wishes to join the list.

Biography

Dr. R. Liz Sockett

Lecturer in Genetics

Phone: + 44 (0)115 9194496Fax: + 44 (0)115 970 9906

Dr. Sockett works with motile bacteria that swim around the environment using propellers called flagella. She is using biochemical and genetic methods to study when motility is "switched on and off", how motor proteins function, and how the regulation of motility and virulence are controlled in bacterial pathogens. With Dr. Smith, she is studying motility and behavioural genetics of Bdellovibrio bacteria. These are predators that prey on other bacteria.

In addition she works in the field of Public Understanding of Science and is the Education Officer for the Society of General Microbiology (SGM). She is also a member of the Board of Education and Training of the American Society for Microbiology.

Dr. Sockett was awarded a University of Nottingham Lord Dearing Award for Teaching and Learning 2000.

Genetics, biochemistry and physiology of bacterial flagellar function

Genetics, biochemistry and physiology of bacterial flagellar functionFlagella are helical propellers with rotary motors that form part of the bacterial cell membrane. Movement of ions through motor proteins results in the rotation of flagella, causing bacteria to swim, but the full mechanistic details are unknown. Swimming is common in bacterial pathogens and is also widespread across non-pathogenic bacterial genera.

We are using genetic and biochemical techniques to study the mode of action of several flagellar motor proteins. With Professor J. Armitage (Oxford University) we are testing interactions between CheY chemotaxis proteins and FliM. We are studying the interaction between the chemotaxis machinery and the flagellar motor by altering FliM and FliG proteins and studying the effect on swimming behaviour. With Dr. Ian Mellor (School of Biological Sciences) we are using electrophysiological techniques to test ion conductance properties of wild-type and "mutant" peptides derived from motor proteins. With Professors Williams and King (Schools of Pharmaceutical Sciences and Mathematics) we are assessing the role of motility in the establishment of a bacterial infection. Projects involve molecular biology, gene manipulation, biochemistry and microscopy.     References

Asai, Y., Kawagishi, I., Sockett, R.E. and Homma, M. (1999) A hybrid motor with H+- and Na+- driven components can rotate virbio polar flagella by using sodium ions. J. Bacteriol. 181 No. 20, p6332-6338.Shah, D.S., Perehinec, T., Stevens, S.E., Aizawa, S.I. and Sockett, R.E. (2000) Flagellar filament of Rhodobacter sphaeroides pH induced polymorphic changes and analysis of the fliC gene. J. Bacteriol. 182 No 18, p5218-5224.

Bostock-Smith, C., Sharman, G.J., Sockett, R.E. and Searle, M. (2000) Evidence for beta sheet conformation in peptides derived from MotB from Rhodobacter sphaeroides. J. Chem Soc. Perkin Trans 2, 479-483.Asai, Y., Kawagishi, I., Sockett, R.E. and Homma, M. (2000) Coupling ion specificity of chimeras between H- and Na- driven motor proteins, MotB and PomB, in Vibrio polar flagella. EMBO J. July 17, 2000; 19 (14) p3639-3648. Sockett, R.E. (1998) Characterising flagella and motile behaviour. In: Bacterial Pathogenesis, Methods in Microbiology, Vol. 27. Williams, Salmond, Ketley Eds. Academic Press, U.K. p.227-237.Sockett, R.E., Goodfellow, I.G.P., Gunther, G., Edge, M.J.E. and Shah, D.S. (1998) "Properties of Rhodobacter sphaeroides flegellar motor proteins". In The Photosynthetic Prokaryotes, Eds. G.A. Preschek, W. Loffelhardt, G. Schmetterer. Plenum Press, pp 693-698.Page, M.D. and Sockett, R.E. (1998) Molecular genetic methods for Paracoccus and Rhodobacter with reference to studies of photosynthesis and respiration. In Methods in Microbiology Vol. 29 "Genetic Methods for Diverse Prokaryotes". Eds. M.C.M. Smith and R.E. Sockett. Academic Press 1999.Goodfellow, I.G.P. et al. (1996) Cloning of the flil gene from R. sphaeroides WS8. FEMS 142, 111-116.Shah, D.S. and Sockett, R.E. (1995) Analysis of the motA flagellar motor gene from Rhodobacter sphaeroides. Mol. Microbiol. 17, 961-969.

Link to Rhodobacter genome page http://www-mmg.med.uth.tmc.edu/sphaeroides/

Publications

Refereed Research Publications

Armitage, J.P. & Sockett, R.E. (1987) Sensory Transduction in Flagellate Bacteria In "Annals of the New York Acad. Sci." 510, 9-15.Sockett, R.E., Armitage, J.P. & M.C.W. Evans (1987) Methylation -independent and methylation-dependent chemotaxis in Rhodobacter sphaeroides and Rhodospirillum rubrum. J. Bacteriol. 169, 5808-5814.Sockett, R.E., Donohue, T.J., Varga, A.R. and Kaplan, S. (1989) Control of Photosynthetic membrane assembly in Rhodobacter sphaeroides mediated by puhA and flanking sequences. J. Bacteriol. 171, 436-446.Armitage, J.P., Havelka, W.A. & Sockett, R.E. (1990) Chemosensory transduction in Rhodobacter sphaeroides Biol. Chem. Hoppe-Seyler 371, p 900.Armitage, J.P., Havelka, W.A. & Sockett, R.E. (1990) Methylation-independent taxis in bacteria. In "Biology of the chemotactic response" J.P. Armitage & J.M. Lackie (eds) Society for General Microbiology Symposium Cambridge University Press Vol 46, 177-197.Sockett, R.E., Foster, J.C.A. and Armitage, J.P. (1990) Molecular biology of the Rhodobacter sphaeroides flagellum. FEMS Symp. 53, 473-479.Sockett, R.E. and Armitage, J.P. (1991) Isolation, characterization and complementation of a paralysed flagellar mutant of Rhodobacter sphaeroides WS8. J. Bacteriol. 173, 2786-2790.Armitage, J.P., Sockett , R.E. and Poole, P. (1991) Behavioural Responses of Bacteria. In "The Prokaryotes" 2nd Ed. Eds A. Ballows, H.G. Truper, M. Dworkin, W. Hader, & K. Schleifer p241-261 Springer-Verlag.Armitage, J.P., Kelly, D.J. & Sockett, R.E. (1995) Flagellate motility, behavioural respnses and active transport in purple non-sulfur bacteria. In Advances in Photosynthesis Volume 2 R.E.Blankenship, M.T. Madigan, & C.E. Bauer (eds) Anoxygenic Photosynthetic Bacteria, pp 1005-1028. Kluwer Publishers Netherlands.Shah, D. S. H., Armitage, J.P. and Sockett, R.E. (1995). Rhodobacter sphaeroides expresses a polypeptide that is similar to MotB of E.coli. J. Bact. 177, 2929-2932.Shah, D.S.H. and Sockett, R.E. (1995). Analysis of the motA flagellar motor gene from Rhodobacter sphaeroides, a bacterium with a unidirectional stop-start flagellum. Mol. Micro. 17, 961-969.T.C. Bonnett, P. Cobine, R.E. Sockett & A.G. McEwan (1995) Phenotypic characterisation & genetic complementation of DMSO respiratory mutants of R.sphaeroides & R.capsulatus. FEMS 133: 163-168.Goodfellow, I.G., Pollitt, C.E. & Sockett, R.E. (1996) Cloning of the fliI gene from Rhodobacter sphaeroides WS8 by analysis of a transposon mutant with impaired motility FEMS 142 111-116.

Gonzalez-Pedrajo, B., Ballado, T., Campos, A., Sockett, R.E., Camarena, L. and Dreyfus, G. (1997) Structural and Genetic Analysis of a Mutant from Rhodobacter sphaeroides deficient in hook length control. J.Bacteriol., Vol.179, No.21, pp.6581-6588.Sockett, R.E., Goodfellow, I.G.P., Gunther, G., Edge, M.J.E. & Shah, D.S.(1998) "Properties of Rhodobacter sphaeroides flagellar motor proteins" In The Photosynthetic Prokaryotes, Eds G.A. Peschek, W. Loffelhardt, G Schmetterer, Pub Plenum Press, p 693-698.Palmer_T, Goodfellow_IPG, Sockett_RE, McEwan_AG, Boxer_DH Characterisation of the mob locus from Rhodobacter sphaeroides required for molybdenum cofactor biosynthesis Biochimica Et Biophysica Acta-Gene Structure And Expression, 1998, Vol.1395, No.2, pp.135-140.Mendum_TA, Sockett_RE, Hirsch_PR The detection of Gram-negative bacterial mRNA from soil by RT-PCR, FEMS Microbiology Letters, 1998, Vol.164, No.2, pp.369-373.Sockett, R.E. (1998) Characterising Flagella and Motile Behaviour In "Methods in Microbiology: Methods for Studying Pathogenic Bacteria" Eds Williams, Salmond, Ketley Academic Press. Vol 27, p227-237.T.A. Mendum, R.E. Sockett & P.R. Hirsch. (1999) Use of competitive PCR & N15 dilution to monitor the response of ammonia oxidising populations Applied & Environmental Microbiology Vol.65, No.9, pp.4155-4162.M.D. Page & R.E. Sockett (1999) Molecular Genetic methods for Paracoccus & Rhodobacter with reference to studies of photosynthesis & respiration pp 427-466 In Methods in Microbiology Volume 29 "Genetic Methods for Diverse Prokaryotes" M.C.M. Smith & R.E. Sockett (eds) Academic Press 1999. ISBN 0-12-521529-0.Y. Asai, I. Kawagishi, R.E. Sockett and M Homma (1999) A hybrid Motor with H+ and Na+-driven components can rotate Vibrio polar flagella using sodium ions. J. Bacteriology 181 No 20 p6332-6338.C Bostock-Smith, GJ Sharman R.E.Sockett & M Searle (2000) Evidence for beta sheet conformation in..peptides derived from MotB from Rhodobacter sphaeroides. J. Chem Soc. Perkin Trans 2, 479-483.Y. Asai, I. Kawagishi, R.E. Sockett and M Homma (2000) Coupling ion specificity of chimeras between H- and Na-driven motor proteins, MotB and PomB, in Vibrio polar flagella.EMBO J. July 17, 2000; 19 (14) in press.D.S. Shah, T. Perehinec, S.E. Stevens & SI Aizawa, R.E. Sockett (2000) Flagellar filament of Rhodobacter sphaeroides pH induced polymorphic changes and analysis of the fliC gene J. Bacteriol Vol 182 No 18 in press.I.G. Goodfellow, KJ Woolley & R.E. Sockett (2000) Characteristics of FliF and FliG from a unidirectional flagellar motor. Gene submitted July 2000.I Mellor, D Shah, M Edge & R.E. Sockett (2000) In vitro and in vivo ion conductance properties of MotB. Mol Microbiol in preparation.

Book chapters

Armitage, J.P., Havelka, W.A. & Sockett, R.E. (1990) Methylation-independent taxis in bacteria. In "Biology of the chemotactic response" J.P. Armitage & J.M. Lackie (eds) Society for General Microbiology Symposium Cambridge University Press Vol 46, 177-197.Armitage, J.P., Sockett , R.E. and Poole, P. (1991) Behavioural Responses of Bacteria. In "The Prokaryotes" 2nd Ed. Eds A. Ballows, H.G. Truper, M. Dworkin, W. Hader, & K. Schleifer p241-261 Springer-Verlag.Armitage, J.P., Kelly, D.J. & Sockett, R.E. (1995) Flagellate motility, behavioural respnses and active transport in purple non-sulfur bacteria. In Advances in Photosynthesis Volume 2 R.E.Blankenship, M.T. Madigan, & C.E. Bauer (eds) Anoxygenic Photosynthetic Bacteria, pp 1005-1028. Kluwer Publishers Netherlands.Sockett, R.E., Goodfellow, I.G.P., Gunther, G., Edge, M.J.E. & Shah, D.S.(1998) "Properties of Rhodobacter sphaeroides flagellar motor proteins" In The Photosynthetic Prokaryotes, Eds G.A. Peschek, W. Loffelhardt, G Schmetterer, Pub Plenum Press, p 693-698.Sockett, R.E. (1998) Characterising Flagella and Motile Behaviour In "Methods in Microbiology: Methods for Studying Pathogenic Bacteria" Eds Williams, Salmond, Ketley Academic Press. Vol 27, p227-237.M.D. Page & R.E. Sockett (1999) Molecular Genetic methods for Paracoccus & Rhodobacter with reference to studies of photosynthesis & respiration pp 427-466 In Methods in Microbiology Volume 29 "Genetic Methods for Diverse Prokaryotes" M.C.M. Smith & R.E. Sockett (eds) Academic Press 1999. ISBN 0-12-521529-0.MCM Smith & R.E. Sockett Eds (1999) Genetics of Diverse Prokaryotes, Methods in Microbiology Vol 29, Academic Press UK. ISBN 0-12-521529-0.

Publications related to teaching

Sockett R.E. (1996) Linking with Disabled Students In BBSRC "Making that link"- A practical guide to scientist-school liaison, BBSRC Nov 1996, page 22, ISBN 0 7084 0578 9.Sockett R.E. (1996) The Young Saplings Club-setting up a primary science club In BBSRC "Making that link" A practical guide to scientist-school liaison BBSRC. Nov 1996 page 5, ISBN 0 7084 0578 9.Sockett, R.E. (1997) A Microbial Christmas. Society for General Microbiology Quarterly (publication of a 1st year UG lecture) Nov 1997, pp 124-5.Sockett, R.E. (1999) "Childrens’ Microbiology Lectures at the Royal Institution" Microbiology Today 26th Feb 1999 p33. ISSN 1 464-0570.Brown N & Sockett R.E. (1999) "Touching Science – A Partnership for Innovation" RNIB New Beacon 981 p4-9.Sockett R.E. (1999) "Going Public Packs": presenting science to members of the public (http://www.socgenmicrobiol.org.uk/PA/edu_car/g_p.htm) Microbiology Today Vol 26 pp18.Sockett, R.E. (2000) "Genetics for the Blind" Microbiology Today Vol 27 pp 49.Sockett, R.E. (2000) "Institute for Learning & Teaching in Higher Education –Should You Join?" Microbiology Today Vol 27 pp114.Sockett, R.E. (2000) An Active learning Module Active Learning in Higher Education (accepted subject to revision).

Collaborative Research

1. Bdellovibrio Research project

Bdellovibrio are tiny predatory bacteria which prey on other Gram negative bacteria, infect them grow inside them and kill them. Dr. Sockett is co-supervising (with Dr Maggie Smith) an NERC-funded PhD student Carey Lambert who is working to set up genetic methodologies for this bacterium, to characterise parts of the Bdellovibrio genome and to determine which physiological properties of the Bdellovibrio contribute to their predatory capabilities. One day they hope that Bdellovibrio could be used therapeutically against antibiotic resistant infections.

References

Tomashow, M.F. et al. (1992) Bdellovibrio host dependence: the search for signal molecules and genes that regulate the intraperiplasmic growth cycle. J. Bacteriol. 174, 5767-5771.

2. Microbiology & Mathematical Modelling of Pseudomonas Wound Infections

Dr. Sockett is working on a collaborative project with Dr John Ward, Ms Julie Croft and Dr Adrian Koerber, this is funded by BBSRC and Wellcome Trust grants that are held jointly with Dr John Ward and Professor John King http://spencer.nott.ac.uk/Research/jrk.html in Theoretic Mechanics, and Professor Paul Williams in the Institute of Infections & Immunity http://www.nottingham.ac.uk/iii/williams.htm. We are studying, in ex vivo laboratory conditions, the contributions of quorum sensing, growth rate, motility and biofilm formation to the establishment of infection processes by Pseudomonas aeruginosa. These bacteria are frequent complications of burn wounds in patients and can be hard to eradicate. We hope that modelling the infection process mathematically may lead towards new strategies for when & how to give treatment. Julie Croft, Paul Williams and Liz Sockett are providing microbiological data this is being modelled by John Ward, Adrian Koerber and John King.

3. Motility, Temperature and Quorum Sensing in Yersinia species

In a new BBSRC funded joint project with Dr Steve Atkinson http://www.nottingham.ac.uk/iii/atkinson.htm and Professor Paul Williams we are investigating the consequences of quorum sensing in Yersinia bacteria. We will be testing how the quorum sensing (QS) system is affected by the temperature at which the bacteria grow (host 37° C or non-host 22/28° C) and how QS regulates flagella motility in Yersinia pseudotuberculosis and Yersinia entercolitica.

Undergraduates Work, Rest & Play

Work

Dr Sockett is a high profile Lecturer and Tutor being awarded a University of Nottingham Lord Dearing Award for Teaching and Learning 2000. She was a Lecturer in Microbiology in the University's School of Biological Sciences between 1991 - 1998 before being appointed to the post of Lecturer in the University's School of Genetics.

During her time at Nottingham Dr Sockett has been Senior Tutor of BSc Microbiology ( previously BSc Applied Microbiological Sciences). She introduced full time, final semester research projects into the degree course to give students 'real' practical experience and introduced a first year 'credited tutorial scheme' designed to enrich microbiology learning by encouraging input from specialist microbiology staff together with essential literature research and essay writing skills. Whilst Lecturing in the School of Biological Sciences she designed a module on Bacterial Pathogens with innovative group work activities for the students. These proved popular with staff, students, employers and external examiners.In addition Dr Sockett is involved in Lecturing on the following undergraduate modules:

Genes and Cellular ControlBacterial Genes and DevelopmentMicrobial PhysiologyMolecular and Environmental Microbiology

Other duties with undergraduates include running Biochemistry/Genetics tutorials, supervising 2nd year dissertations and supervising 3rd year Biochemistry & Genetics projects.In addition Dr Sockett supervises Post Docs and PhD students (see researchers page), lectures in the University's Graduate School and gives lectures to new staff on lecturing techniques.

Rest and Play

University is not just about learning a subject, learning to interact with others and working as a team are equally important. Dr Sockett believes in the complete learning experience and is a regular at student get togethers such as the 'Pre University Welcome Camp' and the nerve racking 'night before results dinner'

Where are they now? (These pages are not available in text form due to constant updates)

If you are a graduate that has been tutored by Dr. Sockett we want to hear from you. We are in the process of publishing a 'where are they now' page on this site with graduates details, photographs, E.mail address and links to personal web sites. E.mail Liz with as much info as you can and attach an a photo in electronic form if you have one. Click on the icon below.

To enter the 'Where are they now pages' click on the graduate icon below

Public Understanding of Science

Genetic and biochemical sciences advance our understanding of the natural world using experiments and observations that are carefully designed and legally controlled. The findings from scientific experiments may offer a new view on the way life works, or may suggest new technologies for health-care or the environments. It is important that scientists explain their findings to all members of the public so that informed decisions can be made as to the way in which scientific knowledge should be used. If this is not done carefully then certain findings may be reported in a sensationalist manner in the press, leading to (usually unwarranted) controversy and fear.

Lord Sainsbury, as minister for science, has in the past stressed the need for better public understanding. More recently he has spoken of making knowledge of science, its achievements and applications accessible to the 'non-scientific audience', leading to the public's engagement in Science.For sometime Dr Sockett has been actively involved in the Public Understanding of Science, leading initiatives with students and science professionals which bring practical science into the classroom, to the public arena and to the visually impaired. She is also currently the education officer for the Society for General Microbiology.

Dr Sockett's involvement

Dr Sockett currently supervises 4 project students working on the public understanding of genetics in primary and secondary schools and by physically impaired pupils. She has previously supervised 6 others, in the last 5 years, all working on public understanding of science projects.She has recently held two Public Understanding of Science Grants jointly with Mr. Norman Brown of RNIB New College, Worcester.

1) A Royal Society-Esso School Science Liaison Grant.2) A Royal Society-British Association Millennium Award.

There are a number of short publications from her PUS work and more in preparation.In her work as Education Officer for the SGM she contributes to a variety of PUS Information including co-editing booklets for BBSRC (e.g. Bacterial Friends and Foes) and for joint activities with Wellcome (Biotechnology Pack for 16+).

She has also written three information sheets with advice for scientists wishing to communicate their work to others. These are available from http://www.socgenmicrobiol.org.uk/PA/edu_car/g_p.htmDr Sockett is a member of several national biological education committees including the UKLSC Education and Careers Committee and the Microbiology in Schools Advisory Committee (http://www.socgenmicrobiol.org.uk/PA/edu_car/misac.htm).

She makes responses on behalf of SGM to planned changes to the national curriculum and A level syllabi. She is a regular lecturer on the Royal Institution Schools lecture programme, speaking to KS2 and 6th form pupils. She presented a display of PUS work at last year’s Tomorrow’s World Live exhibition at Earl’s Court and gives talks at PUS events in the Nottingham area and beyond.

PUS links

SGM Education officer http://www.socgenmicrobiol.org.uk/sgmsetup.htm'Going Public' advice pages on running PUS events http://www.socgenmicrobiol.org.uk/PA/edu_car/g_p.htmAdvice on Education activities relevant to microbiology academicshttp://www.socgenmicrobiol.org.uk/QUA/080001.pdf (needs Adobe Acrobat)Millennium award http://www.socgenmicrobiol.org.uk/QUA/020013.pdf (needs Adobe Acrobat)

Touching Science

Introduction

Touching Science is a project co-supervised by Dr. Liz Sockett and Mr. Norman Brown (Head of Biology at RNIB, New College, Worcester). In it Nottingham University bioscience undergraduates have linked up with high school students, with a visual impairment from RNIB New College, to produce packs explaining modern molecular biology, cloning micro-organisms and food safety issues. These issues are challenging for us all and even more challenging when you have a visual impairment. The "Touching Science" Project tackles those problems. 

Working with A level students at RNIB New College, Worcester

The association began in July 1995 when the Colleges head of biology brought several of his students to a 'Life Science' open day at the University of Nottingham. Dr. Sockett was one of the speakers and suggested a collaboration between undergraduates under her supervision and students at the College in order to design biological learning aids for the visually impaired. Models and tactile diagrams were designed and built including: The tactile bacterium, the nitrogen cycle, enzyme structure and function, DNA structure and genetic engineering models.

Comment from the school

"As a result of the collaboration I will receive some very high quality teaching aids which I know will work with my students, and will improve the content of the areas of biological knowledge covered by the models." ~ Head of Biology.

Links to how some of these models were made and are used can be found at the foot of the page.

Contact Information

If you would like further information on the Touching Science Project, or know someone visually impaired who would like to borrow a pack, please contact the project organisers:

Dr Liz SockettInstitute of GeneticsUniversity of NottinghamQueen's Medical CentreNG7 2UHTel 0115-9194496E-mail: liz.sockett@nottingham.ac.uk

Mr. Norman BrownRNIB New CollegeWhittington RoadWorcester, WR5 2JXTel 01905 763933E-mail: brownn@rnibncw.demon.co.uk

Constructing the tactile bacteriumA Project by Andrew Johnson and Liz Sockett

Problems faced

Many of the features of a bacterium are internal, therefore the model had to be interactive, i.e. it had to be able to be opened to explore the cells contents, and the opening mechanism needed to be simple without requiring visual co-ordination. Velcro was used to adhere the two halves of the bacterium together, which enabled a simple pull from opposite ends of the cell to open up the model. The entire model gave the students an idea of a rod shaped ‘Bacillus’ whereas the opening mechanism also allowed investigation of the cells contents.

The Solution

With respect of the contents of the cell, an ideal material for the bacterial chromosome was one length of poly-ethene rope which had one of the three coils removed. Hence creating the perfect double helix. The two ends of the rope could be fused with heat to form the circular genome. The plasmid was made in a similar fashion.

Quilt padding was chosen to represent the cytoplasm because this emulated the non solid, enveloping nature of true cytoplasm. Ideally a gelatinous material would be used but obviously this was impractical.

To represent ribosomes, ‘fimo’ modelling clay was used, as it could be moulded into the characteristic shape of 70-S ribosomes. Additionally two different coloured pieces of fimo could be used (which could be read by the colour probe) to represent the 50-S and 30-S subunits. Only a few ribosomes were included to allow the model to be kept simple and not cluttered. Tree decorating balls were used to represent the storage granules and pigment bodies due to their interesting textures.The cytoplasmic membrane was chosen to be represented by a soft plastic cylinder. Although this material did not emulate the fluid bi-layer structure of true phospholipid membrane, and memosomes could not be built into this material, it did allow the layered structure to be more discernible when the model was pulled apart, and was durable.

Material representing the cell wall needed to echo the tough, resistant peptidoglycan of the bacterial wall which gives the cell its characteristic shape. Heavy duty cardboard tubing was chosen, which also provided a surface onto which the Velcro opening mechanism for the cell could be placed. The cell was coloured red to allow discrimination of the cell from the white of the cytoplasmic membrane (through sight or the use of the colour probe). The thickness of the material used to represent the cell wall also gave a clue to its identity.

The material to represent the glycocalyx, which a number of cells have, needed to demonstrate the gelatinous nature of this capsule. Sponge appeared to be suitable but would not be durable for continual ‘hands on’ use of the model. Therefore sheets of sponge were treated with rubber solution and stitched together to form the slime jacket for the bacterial cell model. The texture of the sponge allowed easy discrimination between the other features of the cell. A problem with respect to flagella was that the filaments needed to be flexible and slender like true flagella. An ideal material for this was ‘curtain wire’ which is a springy coil or wire encapsulated in a plastic sheath. Pili was represented by sections of plastic sheath from electrical wire. The hollow nature of the pili were represented by this material and could possibly be detected by the students using a matchstick (or similar) to probe down the hollow core.The overall ‘protruding layer’ structure of the model (when pulled apart) was advantageous as it allowed each layer to be recognised and labelled clearly, and also showed the origin of the flagella coming through the cell wall. Feedback relating to the generalised bacteria model after the second visit to New College was as follows. It was suggested that the best way of labelling the model would be to have enlarge print and Braille ‘tags’ on the different features of the model which could be related to an accompanying key. Additionally a matter of safety was raised with respect of the tips of the flagella which unpredictably moved around during exploration of the model possibly catching the face of the students. To overcome this, caps were placed on the tip of each flagella which gave them a more rounded end. The cap was a sleave of heat shrink plastic. It was during the second visit that the idea of using the more realistic plastic cylinder to represent the plasma membrane was aired. As a result of the second visit to New College to following key was created, relating to the labelled tags on the different features of the model. This was reproduced in Braille and large print, and was very brief due to the bulky nature of both large print and Braille.

Key Used

A = Flagella. Thin protein filaments used for motility.B = Pili. Short protein protrusions, involved in attachment to surfaces.E.g. Host body CellsC = Capsule. Thick layer of slime, used for attachment and defence.

Pull Model Apart 

D = Cell wall. Rigid structure containing peptidoglycan. Gives cell its shape.E = Cytoplasmic membrane. Thin phospholipid bi-layer.F = Chromosome. Single circular piece of DNA.G = Plasmid. Small ring of extrachromosomal material.H = Storage granule.

The small beads represent the 70-S ribosomes. The 30-S and 50-S subunits can be felt.

Restriction endonucleasesA Project by Andrew Johnson and Liz Sockett

One reason for the construction of a restriction endonuclease kit was that it would be a good introduction to further models which were to be made depicting gene cloning experiments. An additional reason was that any models relating to restriction of endonuclease sites would also incorporate and enable revision of the basic structure of DNA.

The list of facts about restriction enzymes below, shows a summary of findings from research into the relevant amount of knowledge regarding restriction enzymes which appears to be required for A-level Biology.

Gene splicing depends on restriction enzymes (RE’s) RE’s are naturally occurring enzymes Specific enzymes cut at specific sights on DNA. The location of cut depends of base pairs sequenceRE’s cut both strands of DNA at slightly different points- ‘sticky ends’ are produced Sticky end sequence depends on which one of the many RE’s are used to cut Sticky ends allow two different pieces of DNA which have been cut by the same RE to join together under correct conditions.

The base pair sequence at which the RE’s cut are unique to each RE. Common examples such as Eco R1 are useful.

It was decided that the best way to relate all this information was through a series of interactive DNA models, which could be manipulated by the students, and be pulled apart revealing the sticky ends as though having been treated with endonuclease. Each interactive model would represent the unique sequence of DNA base pairs which would be recognised by a specific restriction enzyme.

Four models were made, showing the recognition sequence, and subsequent sticky ends produced by Eco RI, Bam HI, Bgl II, and Hpa II restriction enzymes which cut at the following sequences.

Eco R I – GAATTC Bam HI – GGATCC

Bgl II – AGATCT Hpa II – GGCC

These four restriction enzymes were chosen as examples to be made into models for a number of reasons. Eco RI is the most widely quoted and is a widely used restriction enzyme. Hpa II was chosen to demonstrate that not all restriction enzymes recognise and cut at a six base pair sequence which results in a four base pair sticky end. Bam HI and Bgl II were chosen to be represented in model form because although the whole six pair sequence which is recognised but each enzyme is different, the same four base pair sticky end is produced.

Problems faced in constructing the RE models

A major problem came to light with respect to the design of these restriction enzyme models, the solution of which dictated the relative success or failure of the model. The problem was finding a suitable material and mechanism to represent the complementary base pairs of the double stranded sections of DNA. The design and mechanism in question had a number of requirements:-

Each A,T, C and G base had to be recognisably different from each other.

Each base pair had to leave a unique complementary fit with its opposing base therefore allowing the formation of a base pair, and only allowing two base pair sticky end overhangs produced by the same restriction enzyme to fit together.

The complementary fit of corresponding bases, forming a base pair needed to be simple, not requiring visual co-ordination, but strong enough to keep both strands of DNA together until the model is pulled apart by students, simulating the action of a restriction enzyme.

The Solution

After consideration, ‘Lego’ bricks were selected to fulfil these criteria, although some modifications to each brick were undertaken to fully satisfy the above requirements. The initial choice for the choosing the cube shaped ‘Lego’ pieces was influenced by the fact that the Lego pieces were differently coloured, allowing colour coding for each base (white for Guanine, yellow for Adenine, red for Cytosine and blue for Thymine) and that although the attachment mechanism doesn’t require visual co-ordination, it was complex enough to be modified, allowing unique binding by complementary bases, with the inhibition of attachment by any other base.The modification of each Lego cube involved either the removal of one of two studs on the cube, or the filling in or one or two hollow stud receptors on the underneath of the cube.

Additional information which the Lego allowed to be incorporated into the model, was the number of hydrogen bonds involved in joining the base pairs together. Each Lego stud represents one hydrogen bond.

The bases were labelled with Braille on a transparent material on one side, and a printed letter, on transparent material, representing the base letter on the other side therefore allowing the colour code of the base to be seen as well as the Brailled or printed letters.

The base sequences were the major feature of these models therefore a simple backbone to each DNA strand was made from a Perspex strip. These strips represented the sugar phosphate backbone of the DNA segments and therefore to give an idea of the simple alternating ‘Sugar molecule, phosphate molecule’ nature of the backbone, red beads were glued onto the model, midway between the base pairs to represent the Phosphates. This additionally gave an indication as to exactly where in relation to the sugar and the Phosphate molecules of the backbone the restriction enzyme cuts.Finally each model was labelled in Braille and large print. The main source of instruction and information to accompany these models was in the form of vocal instruction from a pre-recorded cassette. The following commentary was composed.

" For the following models it is assumed that the student has basic knowledge of the structure of DNA …………….. A restriction enzyme is a DNA cutting enzyme which recognises a certain sequence of A, T or G, C base pairs on a double stranded piece of DNA. These cutting enzymes are found naturally in various Prokaryotes and can be isolated and use as tools to cut DNA. There are many different restriction enzymes with different names, four models are supplied to give an example of four different codes on DNA which are recognised by different endonucleases. These enzymes are listed on an accompanying Brailled sheet along with the DNA codes which they recognise and cut at. The four enzymes are Eco RI, Bam HI, Bgl II and Hpa II. Find the model labelled Eco RI. This represents the code recognised by Eco RI endonuclease, the bases which make up the rungs of the DNA ladder are labelled on the side, either A, T, C or G. They are also colour coded. A is yellow, T is blue, G is white and C is red. The beads along the outside edges of the model represent the phosphate molecules which make up the backbone of the DNA structure. The code for Eco RI is a six letter code, wherever it occurs on DNA he enzyme will make a cut.You will not act as the restriction enzyme, take hold of both backbones of the DNA model and gently pull them away from each other. Hopefully you haven’t broken the model and have found that the DNA has not cut straight through, but has been cut in a zig-zag fashion creating overhanging ends. These are called sticky ends in the world of biotechnology. The overhang for Eco RI is four bases which you can feel. Although these four bases are cut by Eco RI, the whole recognition sequence is six base pairs. The overhangs are called sticky ends because they will readily attach to a complementary overhang. Try this by putting the model back together.Now explore the other two models which have a six base pair code. These models are labelled Bam HI and Bgl II. If you read the code on these models you should find that they are very similar to each other. Infact they are so similar that although recognised by different enzymes, when the DNA is cut the same sticky end overhang is produced. Observe this by pulling both models apart. The sticky end from Bam HI can join with the sticky end from Bgl II. But if you try rejoining to the Eco RI sticky end any of these others you will find that it doesn’t fit.Whilst trying to find the ends together, notice that some bases have three studs. This represents the number of hydrogen bonds between the bases. There are two bonds between Guanine and Cytosine, whereas there are three bonds between Adenine and Thymine.

Not all endonuclease recognition codes are six bases long. This is demonstrated by the model labelled Hpa II. All these enzymes work by cutting sugar phosphate backbone of the DNA creating a nick. The

DNA can be rejoined by a ligase enzyme which re-bonds the backbone. This is shown in an accompanying thermoform diagram."

Gene cloning modelsA Project by Andrew Johnson and Liz Sockett

Research into the amount and detail of information regarding this topic, in general A-Level textbooks revealed the following.

The basic principles behind the gene cloning are outlined, the term recombinant DNA technology is introduced, and the whole aim of gene cloning is explained. The principles behind gene cloning are commonly explained in relation to ‘gene splicing’. The following steps are often described.The use of restriction endonucleases to cut open a bacterial plasmid, and the use of the same endonuclease to remove a segment of DNA from a human cell for example. The techniques used to extract the plasmid and Eukaryotic DNA are not described in detail, although the use of a centrifuge to separate the plasmids was noted.

The insertion of foreign DNA into the plasmid and the use of DNA ligase to re-bond the Sugar Phosphate backbones. The notion that the plasmid is a vector is included.

The mixing of bacteria and plasmids, and the bacterial uptake of plasmids is mentioned, although stimulation of the bacteria to uptake the vector (e.g. Calcium Chloride shock) is not often included.The presence of the plasmid containing the foreign DNA within the bacteria, rapid replication of the bacteria and consequent replication of the plasmid containing the foreign gene, hence amplifying the gene. The mode of replication of the plasmid DNA is not discussed.

It can be seen that the intricacies, and detail of every step are not included, and corresponding laboratory techniques for every step are not mentioned.

A raised tactile flow diagram, using stylised representations for bacteria, plasmids and other relevant features appeared to be suitable to relate the above information. A flow diagram could easily depict the sequence of events involved in gene cloning.

Problems and solutions in constructing the models

The first problem to be resolved was finding a suitable material to represent a simple bacterial cell and Eukaryotic (human) cell from which the plasmid and Eukaryotic DNA could be removed. Acrylic was used because this material could easily be cut in the Life Science Department Workshop, and this material was durable and available in different colours. All shapes which were needed to be cut from acrylic were sketched out as a paper template which could be glued onto the acrylic and cut round.The only features incorporated into these stylised prokaryotic and Eukaryotic cells were simple representations of the genetic material in each cell. Tightly coiled fine wire was used to represent the genetics material because this was easily recognisable through touch. The Eukaryotic cell also had a raised nucleus which enabled identification of its Eukaryotic nature. Only one linear chromosome was placed in this raised nucleus in order to keep the diagram simple and additionally the size of the plasmid in relation to the host bacterial cell and chromosome was greatly exaggerated to enable easy location and identification of this key feature.

The next step of the tactile flow diagram was designed to be interactive, because this step showed the main feature of gene cloning (the exscition of DNA from the Eukaryotic genome and ligation into the plasmid vector forming a recombinant plasmid). The enlarged plasmid DNA and Eukaryotic DNA were made from different colours of acrylic allowing differentiation of the two via use of the light or, colour probe. The problem of how to distinguish the segments of Eukaryotic DNA which contained the gene to be cloned was overcome by using self adhesive velvet patches to represent different genes. The interactive nature of the diagram enabled the student to actually create the recombinant plasmid whilst following the scheme of events. The method of using magnets to allow transfer of different segments of DNA was used because it allowed simple movement of the DNA and easy insertion of the gene into the plasmid via alignment of the sticky ends (represented by a stepped cut at each end of the DNA).

Once the velvet textured gene has been placed in the plasmid, the next problem was how to continue to represent the Eukaryotic gene in the plasmid, once the plasmid had been placed back into the stylised bacterial cell. This was represented by a pipe cleaner, formed into a circle, with all but a small section of the soft textured cleaning material having been burnt away. Hence a small soft textured part of the plasmid remained which correlated with the velvet textured gene which had been placed in the plasmid during the previous step. The first division of the bacteria, complete with recombinant plasmid, was shown to demonstrate the doubling in amount of recombinant plasmid therefore doubling in the number of clones of the Eukaryotic gene every time the bacterial cell divides. It was during the initial visit to New College that it was discovered that one way tactile arrows could be purchased from the RNIB; These were obtained and used on the diagram. The accompanying information for this diagrams was in the form of the following pre-recorded commentary, which enabled the full attention of the student to be direct to the model. The following commentary was recorded onto an easy to use Dictaphone.

" With the diagram infront of you feel towards the top left corner, there is a shape which represents a bacterial cell complete with a plasmid and a chromosome. The chromosome is on the left and is much more bent and twisted that the simple circle shape of the plasmid on the right. OK from this bacteria there are tactile arrows leading down to what represents an enlargement of the plasmid. This is the first step of gene cloning which is the removal of the plasmid from the bacteria. This is done with millions of bacteria at the same time though, not just with the one cell shown here. If you feel towards the top right hand corner there is a shape representing a Eukaryote on the diagram. From this cell there is a short arrow leading down to what represents an enlarged bendy section of the Eukaryotic chromosome. On this section of DNA there are three different genes which are represented by the three bands of velvet on the diagram. This section of DNA is removed from the Eukaryote whilst the plasmids are being removed from the bacteria.

Now for the section step which can be done on the diagram. Using restriction enzymes, genes are cut from the Eukaryotic DNA on the right and put into the plasmid on the left of the diagram. So feel for the section which can be removed from the plasmid and slide it out of the way, then any of three genes textured with velvet can now be taken from the Eukaryotic DNA and placed in the plasmid. The stepped ends of these DNA fragments represent the sticky ends created by the restriction enzymes and therefore if the same restriction enzyme is used on the Eukaryotic DNA as is used on the plasmids, the genes will fit perfectly into the plasmid, and a ligase enzyme can be used to join the cut ends of the DNA. The plasmid which now contains foreign DNA is termed a recombinant plasmid.

The final step of gene cloning is to introduce the recombinant plasmid which hopefully contains the gene you want to clone, back into a bacteria. The arrows leading down from the plasmid show this final step, and lead to a shape which represents a bacteria, into which the recombinant plasmid has been introduced. If you feel at this bacteria there is a chromosome on the left, and the recombinant plasmid on the right. The foreign gene which is being cloned is represented by the soft textured part of the plasmid. The bacteria has been transformed by the plasmid.

Once the bacteria has been transformed, every time it goes through the cell cycle a copy of the plasmid is made and can be found in every daughter cell. This means that the recombinant plasmid, which hopefully contains the recombinant gene you want to copy increases in number, making many clones of the gene.

On the diagram there are two arrows leading away from the transformed bacteria. These arrows represent the first division of the bacteria and lead to two daughter cells containing the recombinant plasmid. Bacterial replication and cell division may take less than twenty minutes therefore every twenty minutes or so, twice as many plasmids and therefore twice as many clones of the gene are produced".

Although not completely relevant to the syllabus, and in excess to the base level of knowledge outlined in various A-Level standard text books, it was decided to outline a few of the problems which are encountered during the procedure of gene cloning, and how these problems are overcome. This was done to allow a greater insight into the techniques used in Biotechnology which may help the visually impaired students in future study of biology and give them a good base knowledge of this topic.

The notion of R-plasmids and Lac-Z genes were chosen to be introduced in the form of ‘genes on plasmids which allow the bacteria to grow on media containing antibiotic’ and ‘genetics colony colour markers’; And it needed to be simply outlined how these genes were used as ‘tools’ to solve the problems which occur during gene cloning. (The full mechanism of how interruption of the Lac-Z gene causes build up of an intermediate in the biosynthesis pathway when bacteria are grown on X-Gal media, turning the colonies white was regarded as a too detailed an account of events.) The two common problems with respect to the outcome of gene cloning (the unsuccessful transformation of bacteria by a recombinant plasmid, and the unsuccessful formation of a recombinant plasmid) were decided to be explained in relation to the use of the ‘genes on plasmids allowing bacteria to grow on media containing antiobiotic’ and ‘genetic colony colour markers’. The format of Minolta paper diagrams appeared suitable to explain these problems and solutions because they were easily produced, and allowed representation of simple shapes such as plasmids containing different genes. Simple diagrams were produced on a computer drawing programme which could then be printed out, and photocopied onto Minolta paper in order to be passed through the appropriate machine to create the tactile nature of the diagram.It was decided that three stylised diagrams would be produced and each diagram would depict one possible outcome of gene cloning with respect to the presence or not of a plasmid in the bacteria (whether the bacteria had been transformed or not) and whether the plasmid in the bacteria contained a gene which is wanting to be cloned (whether the plasmid was recombinant). The use of Minolta paper allowed different types of hatching to be used to represent different genes on the plasmid. A simple key was included in these diagrams.

To emphasise the usefulness of ‘colony colour markers’ (Lac-Z gene) and to give the Visually impaired student an idea of the morphology of bacterial colonies, large petri dishes were used, colonies were moulded from ‘fimo’ modelling clay, and were glued to a petri dish. Fimo was ideal for this purpose because blue and white fimo is available which correlates with the colour of bacterial colonies with and without recombinant plasmids, and fimo could be moulded into a typical ‘entire, convex’ form of a bacterial colony. A petri dish relating to each of the three Minolta paper diagrams was produced.To show that a variety of outcomes can occur from one gene cloning experiment an additional petri dish was made. This contained a random mixture of white and blue colonies. Another problem which arises during gene cloning, and its solution, was incorporated into this petri dish containing a mixture of blue and white colonies. This problem being that genes other than the gene which is wanting to be cloned can splice into the plasmid. Antibody detection of the colonies which are expressing the cloning gene could be demonstrated at this point. A mechanism was therefore required which would allow material which could represent a monoclonal antibody against the cloned gene produced, bind to a proportion of the blue colonies on the petri dish containing both blue and white colonies. This phenomenon was demonstrated by the use of small magnets being placed beneath certain blue colonies and ball bearings representing the monoclonal antibodies.

The Nitrogen CycleA project by Cathy Durbridge and Liz Sockett

Tactile representation of the Nitrogen Cycle: Construction of a representative model

The Nitrogen cycle in diagrammatic form is fairly complex and would be difficult in most cases to follow in a logical manner. The sighted pupil can of course ‘take the whole diagram in’ in one look, so for them a logical approach is not crucial. The visually impaired student on the other hand can only take in one section of the diagram at a time, so it is already a more demanding task. Therefore the cycle had to be simplified, which entailed leaving out some of the extra processes involved in reality, such as the effect of lightning which is generally regarded as an insignificant part of the cycle. The main points of the subject were illustrated in on a wall chart (a method which had previously proven suitable in showing Mitosis and Meiosis). The cycle can be followed by a series of arrows and each section represented by a model which was considered a more interesting way of presenting the information than simply using braille.Models of the bacteria involved FIMO proved to be very useful at this stage for model making. It is relatively inexpensive, widely available, easy to use and store, and can be modelled into just about any shape. As well as this, it is available in a number of different colours.

Three different shaped bacteria were made to represent the stages in the cycle where soil bacteria are involved, i.e. decomposition, denitrification, nitrogen fixation and nitrification. The shapes represent the following;

Spherical: cocci (yellow)Rod shaped: bacilli (red)Helical: spirila (blue).

The bacilli flagella, which are thin strips of elastic pushed into the FIMO before it was hardened by heating to 120oC. Unfortunately this was not as successful as it could have been as, although the flagella was discernible by touch, some of the elastic threads did not withstand the heating treatment, and melted. A more suitable material therefore, would probably be a thin wire strip, such as that found in pipe cleaners, or in ties for dustbin tags. These would be thin enough to show some flexibility as is found in flagella, but would be resistant to heat.

The same three bacterial shapes were used to represent all of the different stages where bacteria are involved, despite the fact that this is slightly misleading, as in reality different bacterial species are responsible for different stages, e.g. Nitrobacter is responsible for nitrification and Rhizobium is responsible for nitrogen fixation. It would have been too complex to represent this on the cycle itself, so it is explained in the lesson notes.

The Chemical Forms of Nitrogen

The centre of the cycle consists of three raised plastic platforms with Braille labelling on black sticky backed plastic on the top left hand corner, and enlarged print labels below to show the particular forms of nitrogen. Three main forms of nitrogen are shown, Ammonia, Nitrite and Nitrate, and the Braille labels show both the chemical symbols and the written words. The fact that the blocks are raised off the backing board draws attention to them. It was planned originally to put the Braille labels on transparent Braille Dymo tape above the print labelling.

Labelling

All of the labelling is present in both enlarged print and in Braille so it is suitable for both partially sighted and blind students. The print is size 36 as, according to my questionnaire this is a discernible size. The print labels were covered in thin transparent sticky backed plastic purely to increase their durability.

The Braille is done on transparent acetate, using a hand frame and puncher. These labels are consistently placed below the print labels so that they are easy to find. I could not make the labels any bigger than they are as the cycle would look and feel overcrowded. If this was the case, I could have used a key, but I think that it is clear the way it stands.As well as labelling the processes, the individual models are labelled, the sheep, the trees and the cloud etc., so there is no doubt about their identity.

The Arrows

The arrows were used on the cycle are made of a number of different materials. Small yellow tactile arrows, invented for the prime reason of indicating a set direction to a blind or partially sighted student, are found at the start of each large arrow. They feel smooth if felt in the intended direction and rough if scanned the other way. (This concept was developed during the research project conducted by Schiff and Levi in 1979).

Although these arrows could have been used for the whole of the cycle, they are very small and inflexible and were therefore not ideal. After advice from the RNIB Tactile Diagrams Unit, it was decided to use solder wire. It is convenient for a large scale model, and worked particularly well for the cycle and is very malleable. It is not too heavy and so easily attached to the board, and it is inexpensive and widely available. It was also about the right thickness to connect well to the small tactile arrow units so the arrows could be followed in one smooth movement.

An arrow head was added to the other end of each arrow so as to make them more visually accurate for partially sighted students. A piece of plastic lattice work, cut down to size and sanded down using coarse sand paper was suitable for this. After advice these were painted bright red so they stood out more from the white background of the board. The arrow heads also served to indicate where a model or an important stage in the Nitrogen Cycle had been reached.

The board

Nearly all the information read on producing tactile diagrams emphasised the need for reducing clutter so I followed their advice, and choose a board of one metre2. It is actually a bit heavier than I hoped it would be as it is made from thick wood, but this will increase its durability and any material of that size would be fairly heavy. As it is not for a model that will be carried around, the weight is not a crucial factor.

The board is painted in white matt paint, which protects the wood, while providing the maximum contrast with the enlarged print labels, so they can be read more easily. The edges of the board were sanded down so it is all smooth to the touch.

Attaching the Components to the Board

A strong glue (Araldite) was used to attach the different components to the base board. The labels were attached using Cow Gum. It would have been advantageous to bolt the Perspex blocks on to the board from the back; to increase the durability of the model, but this would disrupt the print labelling. The cloud was attached using Velcro.

The Individual Stages Denitrification

A cloud was used to represent the atmosphere, although this has its disadvantages. The cloud of cotton wool on a cardboard cut out base may be a fairly accurate visual representation, but from a tactile point of view it is not entirely satisfactory. If a cloud is ‘felt’, it is damp and cold, and just that, rather than an actual object that can be grasped. However, it seems impossible to represent this and to make it recognisable to a visually impaired student, so the cotton wool idea was used. Due to the fact that the cardboard and the cotton wool is not durable, Velcro was used to attach it to the board instead of the glue used for other objects. This enables a new cloud to be made and attached in the event that the original one becomes too tattered for use.

Harvesting

On the left hand side of the cycle three sheaves of corn are attached to the board to represent crops that have assimilated nitrate from the soil into protein and then have been transferred; therefore where nitrogen is irretrievably lost from the cycle.

Plant Assimilation

The model of the tree is made from FIMO and symbolises non-harvestable plant communities that have assimilated nitrates from the soil into plant protein. The tree represents a few problems in that, however it was made it would not feel like the real thing, and could not be made to any sort of scale. Perhaps the tree model is more suitable for the partially sighted student than for the completely blind student.

Animal Assimilation

The original idea was to use a cow model, but the sheep was more easily discernible by touch. The plastic sheep from a toy shop lacked a certain tactile aesthetic value so it was covered in some fleece to add an authenticity to it! The back of the sheep was removed to allow it to be fastened securely to the base board by a flat surface.

Tactile Diagrams

Although the Nitrogen cycle is the main model for this topic, some tactile diagrams were used to help explain aspects considered in the lesson notes.

Tactile Diagram of a Root Hair Cell

A simplified diagram of a root hair cell was used, to show its general structure and outline. This will be useful when the students are considering the formation of root nodules. The diagram was drawn initially, and a key made, and the Braille was added using a Lettroset of transfer dots. This could then be put onto Minolta paper using a stereo copier, to produce a raised diagram.

Root Nodule Thermoform

In order to give some indication of the size and position of root nodules on a leguminous plant a dried example of a clover root network together with thermoform nodules were made.

The master copy was put onto A4 sized card, the roots having been washed and dried. There were some roots with nodules, and some without, so a comparison between the two could be made.A number of the roots were removed in order to decrease the amount of clutter and background noise in the diagram, and a good example of a root with a large nodule was highlighted so it could be felt more clearly.

In addition a small Minolta diagram showing the positioning of root nodules was made to reinforce the Thermoform model.

Lesson notes accompanying the model can be downloaded o the site.

Education ActivitiesLecturing

In addition to Lecturing at the University of Nottingham and working with the visually impaired Dr Sockett is the Education Officer for the Society of General Microbiology, regularly giving public lectures and talks to school children. Some of these are listed below:

Invited Lectures as a Science Communicator

SET week, 1995 Lecturer to 200 members of W.I. on Genetically Engineered Food. Meeting organised by Dr Mike Davey, Nottingham University campus.

Royal Institution lectures to children, Royal Institution, London, 'Motoring Microbes: Bacterial Movement' April 30th 1998, Nov 10th 1998, June 12th 2000, July 10th 2000.

Royal Institution SET Week, Royal Institution London, March 15th 1999, 'Bacteria and Viruses'. British Association for the Advancement of Science, Public Lecture to 2000, Broadway Cinema,

Nottingham, 'Marvellous Microbes', Nov 23rd 1999. Graduate Careers lectures at UK Life Science Committee Fairs, Nov 1999, Nov 2000.

Lectures in Schools

Uppingham School, Rutland, Genetic Engineering and bioscience careers, 1994. RNIB School, Worcester, Genetics and Biochemistry, May 1995, Mar 1996. Whitegate Primary School, Clifton, Nott'm, 'Marvellous Microbes', 1995. Christ the King School, Nott'm (6th form), 'Cloning Genes', May 22nd 1997. Holgate School, Hucknall, Notts' (Science Fair), 'Discovering Microbiology', June 12th 1997. Bramcote Scouts, 'Microbes and Recycling' Nov 14th 1997. Glaisdale School, Nott'm, 'Micro-organisms good, bad and ugly', May 24th 1999. Southwell Minster School, Open forum on Genetic Engineering, Dec 15th 2000. Oakham School, Rutland, 'Love Bugs' Feb 14th 2000.

Genetics with models

Dr Sockett supervises innovative projects for final year undergraduate students who wish to pursue careers in education. The projects include designing methods for teaching normally complicated subjects to school children and tactile models for explaining science to people with visual impairments.Examples of projects for the visually impaired can be found in the touching science pages.

Projects for school children include learning the genetic code by making a friendship bracelet from different colours representing codons and using toys such as Mr Potatohead (Genetic code and Understanding chromosomes pages).

Genetic Code

• The human body is made of millions of cells, in the nucleus of each cell are the chromosomes There are 22 pairs of "normal chromosomes" plus two sex chromosomes either a pair of X chromosomes in females or one X plus one Y in males• Chromosomes are made of DNA coding for each gene and the "switches" to turn the genes on and off• This means that different genes are turned on in different parts of the body to make teeth, hair blood etc• When a gene is switched on a small message is copied from the correct part of the chromosome• This message is short and can move from the nucleus to the protein-making machinery of the cell• Each message is called a "messenger RNA" it is written in genetic code• The code is made up of chemicals called nucleotides there are 4 sorts Gs As Us and Cs• Each gene and its message is just a string of these nucleotides in a row• Each messenger RNA is decoded by the protein-making machinery of the cell• Proteins are then made containing different ammo-acids depending on what the code specifies.• Three letters in the genetic code for each amino-acid , long chains of amino-acids joined together make proteins• Each amino-acid has a different name which is represented by a letter of the alphabet (but there are only 20 different ones of them)• Each protein is like a long word made of the letters• Each different type of amino-acid gives the protein different properties For example proteins with lots of Ps in them are springy as in curly hair or knee joints Proteins with Cs and Hs in them make coloured proteins like those in blood and eyes, other proteins can act as enzymes like those in saliva that break down starches and sugars in our food• The proteins form part of the cells in different parts of the body and give them the correct properties (making livers different to toenails and tongues different to eyelids)Getting familiar with the genetic code• Below is the genetic code written out• To get used to the code we will use it to build up simple "protein words" made of amino-acids• In real life proteins are made up of hundreds of amino-acids but by making short protein words you can learn the code• All living creatures from microbes to marigolds to mammoths to man use this code in their cells

Make a genetic code friendship bracelet

You are given a set of different coloured beads that represent the Gs As Us and Cs, some string and a copy of the genetic code in colour. Use these to build up a genetic friendship bracelet. Remember that the amino-acids are like letters of the alphabet but a few are missing, you can't do words containing B, J, 0, U, X or Z. So for example Genetics would be GGC GAA AAC GAG ACA AUC UGC UCA You will find that use can use more than one code for some letters, that's OK. If you want to make multiple words put a "stop" code between each new word If you like you can use a marker pen to write the Gs As Us and Cs onto the beads of the finished bracelet.

Keep this paper so you know the code forever. Wear the bracelet to remind you that genetics is a friendly topic!

Genetic Code (amino-acids in black) (in colour on the web)

UUU F UUC F UUA L UUG LUCU S UCC S UCA S UCG SUAU Y UAC Y UAA stop UAG stopUGU C UGC C UGA stop UGG W

CUU L CUC L CUA L CUG LCUU P CCC P CCA P CCG PCAU H CAC H CAA Q CAG QCGU R CGC R CGA R CGG R

AUU I AUC I AUA I AUG MACU T ACC T ACA T ACG TAAU N AAC N AAA K AAG KAGU S AGC S AGA R AGG R

GUU V GUC V GUA V GUG VGCU A GCC A GCA A GCG AGAU D GAC D GAA E GAG EGGU G GGC G GGA G GGG G

Understanding ChromosomesUnderstanding Chromosomes is a project by Liz Newton (B.Sc. Hons Genetics 2000) and Liz Sockett

The Mr Potatohead model

Mr Potatohead models (or similar) are adapted to show differing features such as hair colour or hairy ears and differently patterned/coloured pipe-cleaner chromosomes are used to explain the idea of genes, variation and inheritance. The pupils usually key stage 2-3 have to build a model in a tray (which also contains the corresponding set of chromosomes), compare its features to the one on the stand, look at the chromosomes of both models and decide what is different about them.

This way of looking at different features is a non-discriminatory method as it concerns features of a toy not a person. Pupils to understand how genes encode for our features without the potentially sensitive comparisons between classmates.

Further work with Mr. and Mrs. Potatohead and their offspring shows simple principles of genetic crossing and how children inherit genes from their parents.