Exercise 1Exercise 1

MicroscopyMicroscopy

enables one to study objects too small to be enables one to study objects too small to be seen and examined with the naked eyeseen and examined with the naked eye

an optical instrument consisting of a system of an optical instrument consisting of a system of lenses that gives sharp, distinct and highly lenses that gives sharp, distinct and highly magnified images of minute objectsmagnified images of minute objects

different types depend on usage, source of different types depend on usage, source of light, and maximum capacity to enlarge an light, and maximum capacity to enlarge an objectobject

uses ordinary room lighting condition, easier to uses ordinary room lighting condition, easier to move about and usemove about and use

A. Parts and FunctionsA. Parts and Functions

1. Eyepiece/Ocular – topmost portion1. Eyepiece/Ocular – topmost portion Small, removable tube containing lenses with Small, removable tube containing lenses with

the magnifying power etched on its surfacethe magnifying power etched on its surface Part where the specimen is viewedPart where the specimen is viewed Intermediate image projected by the objective Intermediate image projected by the objective

is enlarged by the eyepiece.is enlarged by the eyepiece. *Hence, the term compound microscope is *Hence, the term compound microscope is

derived from the fact that the specimen is derived from the fact that the specimen is magnified twice, first by the objective and magnified twice, first by the objective and second by the eyepiece. The final image second by the eyepiece. The final image formed is a formed is a virtual imagevirtual image..

2. Extension/Draw tube – Through this 2. Extension/Draw tube – Through this tube, the image is projected over a tube, the image is projected over a distancedistance

3. Body tube – wide hollow cylindrical tube 3. Body tube – wide hollow cylindrical tube which provides a short distance for the which provides a short distance for the image/light to pass throughimage/light to pass through

4. Revolving nosepiece – attached beneath 4. Revolving nosepiece – attached beneath the body tube which serves as the base the body tube which serves as the base for one or more objectives. It can be for one or more objectives. It can be rotated to position the appropriate rotated to position the appropriate objective to be used (allows convenient objective to be used (allows convenient exchange of the objectives)exchange of the objectives)

5. Objectives – small narrow tubes containing 5. Objectives – small narrow tubes containing compound lenses for magnificationcompound lenses for magnification

a. low power objective (LPO) – shortest, 10x a. low power objective (LPO) – shortest, 10x (magnification), 5mm (working distance)(magnification), 5mm (working distance)

b. high power objective (HPO) – 40-43x, 0.46mmb. high power objective (HPO) – 40-43x, 0.46mmc. oil immersion objective (OIO) – requires that oil c. oil immersion objective (OIO) – requires that oil

be placed between the objective lens and the be placed between the objective lens and the coverslip for a distinct image to form, 100x, coverslip for a distinct image to form, 100x, 0.13mm0.13mm

d. scanner – allows a wider area of the specimen d. scanner – allows a wider area of the specimen to be viewed, 2.5xto be viewed, 2.5x

6. Arm – curved portion connecting the 6. Arm – curved portion connecting the body tube to the base of the microscope; body tube to the base of the microscope; this is where the microscope is held for this is where the microscope is held for carrying or tilting; supports the body tube carrying or tilting; supports the body tube and adjustment knobs; permits and adjustment knobs; permits adjustment of the stage to a desired adjustment of the stage to a desired angleangle

7. Adjustment knobs – two pairs of knobs found 7. Adjustment knobs – two pairs of knobs found on both sides of the armon both sides of the arm

a. Coarse adjustment knob – larger pair; adjust or a. Coarse adjustment knob – larger pair; adjust or moves the body tube, together with the moves the body tube, together with the objectives, up and down easily. It is used to objectives, up and down easily. It is used to bring into focus the specimen to be observed.bring into focus the specimen to be observed.

b. Fine adjustment knob – smaller pair; adjusts b. Fine adjustment knob – smaller pair; adjusts slowly and is used to sharpen the focusslowly and is used to sharpen the focus

8. Inclination joint – found at the base of the arm which 8. Inclination joint – found at the base of the arm which allows the upper portion of the microscope to be tiltedallows the upper portion of the microscope to be tilted

9. Stage – place where the glass slide (which contains the 9. Stage – place where the glass slide (which contains the specimen to be observed) is placed; contains the stage specimen to be observed) is placed; contains the stage clips and a holeclips and a hole

10. Stage clip – holds the slide in place10. Stage clip – holds the slide in place11. Opening/Aperture – where light passes through11. Opening/Aperture – where light passes through12. Aperture disc – movable; connected to and beneath 12. Aperture disc – movable; connected to and beneath

the stage contains a series of holes with different sizes the stage contains a series of holes with different sizes for the regulation of the incoming lightfor the regulation of the incoming light

13. Substage condenser – used to concentrate the 13. Substage condenser – used to concentrate the incoming lightincoming light

14. Iris diaphragm – below the condenser; with a movable 14. Iris diaphragm – below the condenser; with a movable lever, also for regulating the incoming lightlever, also for regulating the incoming light

15. Mirror – found at the base of the microscope which is 15. Mirror – found at the base of the microscope which is used to direct the light through the opening of the stageused to direct the light through the opening of the stage

16. Pillar – region connecting the inclination joint with the 16. Pillar – region connecting the inclination joint with the stand at the base of the microscope. Together they stand at the base of the microscope. Together they support and hold the microscope in a steady positionsupport and hold the microscope in a steady position

17. Base – keeps the microscope steady at any position 17. Base – keeps the microscope steady at any position of the stageof the stage

Parfocal – means that the objectives are Parfocal – means that the objectives are optically and mechanically designed so optically and mechanically designed so that the distance between the specimen that the distance between the specimen and the aerial image is always constant. and the aerial image is always constant. Slight refocusing with the aid of fine focus Slight refocusing with the aid of fine focus knob is sufficient to restore critical knob is sufficient to restore critical sharpness of the image after changing sharpness of the image after changing from objective to another, thus the coarse from objective to another, thus the coarse focus knob need not be operated.focus knob need not be operated.

B. Use/Operation of the B. Use/Operation of the MicroscopeMicroscope

READ the manual!READ the manual!

C. Care of the MicroscopeC. Care of the Microscope

Read the manual…Read the manual…

D. Terms and Concepts in D. Terms and Concepts in MicroscopyMicroscopy

Resolving PowerResolving Power Limit of resolutionLimit of resolution Working distanceWorking distance Field of VisionField of Vision Magnification (Linear)Magnification (Linear) ParfocalParfocal

E. Calibration of the E. Calibration of the MicroscopeMicroscope

*1mm = 1000 micrometers*1mm = 1000 micrometers The ocular micrometer is a glass disc with mounted The ocular micrometer is a glass disc with mounted

scale. It is inserted into the eyepiece and must be scale. It is inserted into the eyepiece and must be calibrated for the particular objective, eyepiece and calibrated for the particular objective, eyepiece and tube length employed before measurements are made. tube length employed before measurements are made. The student microscope has a fixed tube length. The student microscope has a fixed tube length.

A stage micrometer is a glass slide with graduations of A stage micrometer is a glass slide with graduations of known intervals. The length of one small division is known intervals. The length of one small division is 0.01 mm or 10 micrometers, whereas one big division 0.01 mm or 10 micrometers, whereas one big division is 0.1 mm or 100 micrometers.is 0.1 mm or 100 micrometers.

1. Calibration of the Ocular Micrometer1. Calibration of the Ocular Micrometer Use this formula to determine the value Use this formula to determine the value

of one division on the ocular micrometer:of one division on the ocular micrometer: Calibration factor = Calibration factor = SM divisions SM divisions

subtended by OM x Value of one SM divsubtended by OM x Value of one SM div

OM division subtended by SMOM division subtended by SM

2. Measurement of the Specimen2. Measurement of the Specimen The specimen is measured by counting The specimen is measured by counting

the number of divisions it covers on the the number of divisions it covers on the ocular micrometer. Knowing the ocular micrometer. Knowing the calibration factor, you can compute the calibration factor, you can compute the size of the specimen in micrometers or size of the specimen in micrometers or millimeters.millimeters.

F. Techniques for Preparing F. Techniques for Preparing Specimens for Light Specimens for Light MicroscopyMicroscopy

Wet mount technique – organism can be Wet mount technique – organism can be observed in its normal living condition. observed in its normal living condition. Simple wet mount involves placing on a glass Simple wet mount involves placing on a glass slide a drop of the specimen which is slide a drop of the specimen which is suspended in a fluid. If the specimen is dry, suspended in a fluid. If the specimen is dry, a drop of water is added to the specimen on a drop of water is added to the specimen on the glass slide. A coverslip is placed on top the glass slide. A coverslip is placed on top of the specimen to prevent drying and to of the specimen to prevent drying and to flatten the specimen in order to avoid the flatten the specimen in order to avoid the refraction of light.refraction of light.

Fixed and Stained preparationFixed and Stained preparation

G. Dissecting MicroscopeG. Dissecting Microscope

consists of a single lens which provides consists of a single lens which provides a large and clear field and gives a a large and clear field and gives a magnification of 6x to 20xmagnification of 6x to 20x

for the study of large or thick specimensfor the study of large or thick specimens useful in examining small organisms and useful in examining small organisms and

parts of large organismsparts of large organisms gives an erect imagegives an erect image

Exercise 2Exercise 2

Allium cepaAllium cepa

Hydrilla verticillataHydrilla verticillata

tomato and red peppertomato and red pepper

Rhoeo discolorRhoeo discolor

crystalscrystals

coconutcoconut

DiffusionDiffusion

OsmosisOsmosis

HypertonicHypertonic HypotonicHypotonic IsotonicIsotonic

hypertonichypertonic

Semi-permeabilitySemi-permeability Phospholipid bilayerPhospholipid bilayer

Exercise 3Exercise 3

PhotosynthesisPhotosynthesis

Capture solar energy and utilize for the Capture solar energy and utilize for the synthesis of organic compounds from synthesis of organic compounds from water and carbon dioxide in a series of water and carbon dioxide in a series of enzyme-mediated complex reactionenzyme-mediated complex reaction

Chloroplasts (thylakoid membranes)Chloroplasts (thylakoid membranes)

PhotosynthesisPhotosynthesis

6 CO6 CO22 + 12 H + 12 H22O O

Light and chlorophyllLight and chlorophyll---) ---) CC66HH1212OO66 + 6 H + 6 H22O + 6 OO + 6 O22

Four stepsFour steps

1. Absorption of light (directly light 1. Absorption of light (directly light dependent)dependent)

HH22O + 2 NADP+ O + 2 NADP+ lightlight---) 2 H---) 2 H++ + 2 NADPH + + 2 NADPH +

OO22

2. Electron transport (directly light 2. Electron transport (directly light dependent)dependent)

3. ATP generation (directly light 3. ATP generation (directly light dependent)dependent)

4. Carbon fixation (indirectly light 4. Carbon fixation (indirectly light dependent)dependent)

6 CO6 CO22 + 12 H + 12 H22O + 18 ATP + 12 NADPH ---) O + 18 ATP + 12 NADPH ---)

CC66HH1212OO6 6 + 18 ADP + 12 NADP + 6 H+ 18 ADP + 12 NADP + 6 H++

RespirationRespiration

Slow, controlled release of energy Slow, controlled release of energy through the enzymatic breakdown of through the enzymatic breakdown of organic substances into simpler productsorganic substances into simpler products

Mitochondria (inner membrane)Mitochondria (inner membrane)

RespirationRespiration

AerobicAerobic

CC66HH1212OO66 + 6 H + 6 H22O + 6 OO + 6 O22

EnzymesEnzymes-----) -----) 6 CO6 CO22 + 12 H + 12 H22O O

+ Energy+ Energy

Glucose + Oxygen = Carbon Dioxide + Glucose + Oxygen = Carbon Dioxide + Water + EnergyWater + Energy

AnaerobicAnaerobic

CC66HH1212OO6 6 EnzymesEnzymes-----) 2CO-----) 2CO22 + +

CC22HH55OH (ethanol) + EnergyOH (ethanol) + Energy

CC66HH1212OO6 6 EnzymesEnzymes-----) 2C-----) 2C33HH66OO33

(lactic acid) + Energy(lactic acid) + Energy

Cellular Respiration in Cellular Respiration in yeastyeast

Respire both aerobically and Respire both aerobically and anaerobicallyanaerobically

Easily handledEasily handled If oxygen is available, it will respire both If oxygen is available, it will respire both

aerobically and anaerobicallyaerobically and anaerobically

Cell CycleCell Cycle

Exercise 4 MitosisExercise 4 Mitosis

Prophase – shortening & thickening of Prophase – shortening & thickening of chromosomes due to coiling of chromosomes due to coiling of chromosome threadchromosome thread

- At late prophase – chromosomes can be - At late prophase – chromosomes can be seen to consist of 2 strands known as seen to consist of 2 strands known as sister chromatids which are attached sister chromatids which are attached together through the centromere; nuclear together through the centromere; nuclear membrane and nucleolus are no longer membrane and nucleolus are no longer visible at the end of prophasevisible at the end of prophase

Metaphase – chromosomes have already Metaphase – chromosomes have already shortened to a fraction of their former shortened to a fraction of their former length and are much thickerlength and are much thicker

- Chromosomes are now lined up in a - Chromosomes are now lined up in a single plane across the center of the cell single plane across the center of the cell called the called the metaphase plate or equatorial metaphase plate or equatorial plane or zoneplane or zone

Anaphase – sister chromatids move to Anaphase – sister chromatids move to opposite ends or poles of the cellopposite ends or poles of the cell

- They appear to be pulled apart by thread-like They appear to be pulled apart by thread-like spindle fibers attached to the centromerespindle fibers attached to the centromere

- The centromere of each of the chromatids The centromere of each of the chromatids become totally functional during this stagebecome totally functional during this stage

- Upon separation from each other, the Upon separation from each other, the chromatids are now considered as individual chromatids are now considered as individual chromosomeschromosomes

Telophase – at this point, the Telophase – at this point, the chromosomes have reached the opposite chromosomes have reached the opposite poles. They start to uncoil and lengthen. poles. They start to uncoil and lengthen. A nuclear envelope reforms about each A nuclear envelope reforms about each set of chromosomes, the nucleolus set of chromosomes, the nucleolus reappears in each pole and cytokinesis reappears in each pole and cytokinesis takes place. Each daughter cell takes place. Each daughter cell proceeds to the interphase condition and proceeds to the interphase condition and begin to carry out their physiological fnxbegin to carry out their physiological fnx

Cytokinesis – cytoplasmic Cytokinesis – cytoplasmic divisiondivision

Animal cell – begins with the formation of Animal cell – begins with the formation of cleavage furrowcleavage furrow running from the running from the opposite sides of the cell, parallel to the opposite sides of the cell, parallel to the equatorial plate. The furrow becomes equatorial plate. The furrow becomes progressively deeper, until it cuts progressively deeper, until it cuts completely through the cell producing two completely through the cell producing two new cells. It progresses from the new cells. It progresses from the periphery to the middleperiphery to the middle

Plant cell – forms a Plant cell – forms a plateplate in the center of in the center of the cytoplasm and slowly becomes larger the cytoplasm and slowly becomes larger until its edges reach the outer surface. until its edges reach the outer surface. The cell and the cell’s contents are cut in The cell and the cell’s contents are cut in two. It progresses from the two. It progresses from the middle to the middle to the peripheryperiphery

Interphase

                                  

                                

Prophase

                                  

                                

Metaphase

                                  

                                

Anaphase

                                  

                                

Telophase