document.docxConcept Learning Objective Key informationo Define the meaning of

molecular biology Describe molecular biology as the study

of biology on a molecular basis Discuss the formation of ionic bonds Discuss the formation of covalent bonds

Molecular Biology is the study of Biology on a molecular basis. This means that it looks at all the interactions that occur between molecules. In order to form compounds atoms must form bonds, these bonds may involve the sharing of electrons (covalent) or the creation of electrically charged particles which are then attracted to each other (ionic). A weak or temporary bond may form between some electrically charged particles- we call these hydrogen bonds

o Discuss the bonding properties of carbon

Define the term organic molecule Discuss the atomic structure and

bonding properties of carbon Discuss the versatility of carbon

Any chemical that has been produced by a living organisms is referred to as organic. One exception to this statement is carbon dioxide. Organic molecules tend to contain carbon. Carbon is considered to be a versatile molecule as it can form up to 4 covalent bonds and therefore can form a large number of stable compounds

o Discuss the importance of carbon in the formation of organic molecules

Discuss the importance of carbon in the formation of biological molecules

Recognise the outline form for common organic molecules

Discuss the role of organic molecules in molecular biology

Carbon along with hydrogen and oxygen are essential components of many organic molecules. Nitrogen is also essential for amino acids. Organic molecules are important as an energy source, for growth and repair and for energy storage and insulation.

o Define metabolism, anabolism and catabolism

o Define and describe metabolic pathways

o Give an example of an enzyme that is part of a metabolic pathway and link to lower activation energy

Define metabolism as, the sum of the biochemical reactions that are needed to sustain life

Outline anabolic reactions Outline catabolic reactions Explain what is meant by metabolic

pathway Discuss the importance of metabolic

pathways in organisms Give examples of metabolic pathways in

a cell include specific enzymes and describe how they lower activation energy

Metabolism refers to the chemical reactions that take place in the cells. An anabolic reaction is one that requires energy to make larger molecules from smaller ones eg the synthesis of protein. Catabolism is a reaction the gives out energy when larger molecules are broken down in to smaller ones, eg the breakdown of sugar in respiration. Some reactions need to be controlled by the body and therefore will happen in steps. This is referred to as a metabolic pathway- eg photosynthesis

o Outline vitalism and urea synthesis

Define vitalism Discuss the process of urea synthesis Discuss the idea that synthetic urea has

allowed us to falsify theories

Vitalism is a belief that living things are driven by a vital internal force. This suggests that only living things can make organic molecules. This was disproved by the accidental (serendipitous) discovery of synthetic urea by Friedrich Wohler 1828, who was able to rearrange the molecular structure of ammonium citrate to form urea.

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Concept Objective Commento Describe the chemical

properties of water molecules Describe the structure of a water

molecule Discuss the polarity of water Describe the formation of

hydrogen bonds

Water is made from one oxygen and two hydrogen atoms, it is a polar molecule which means that one end has a positive charge and the other has a negative charge. A water molecule will form an attractive bond (hydrogen bond) with neighboring water molecules, we call this cohesion, it will also for bonds with other polar molecules which we call adhesion

o Discuss the properties of water and link to biological importance

Identify the key properties of water

Discuss the biological importance of water

Link the absence of water to the collapse of biological systems

Water is an essential component of life. It is important due to its properties as a solvent, for temperature regulation and due to its cohesive and adhesive properties

o Discuss the meaning of hydrophilic and hydrophobic

Define hydrophilic and give examples

Define hydrophobic and give examples

Define amphipathic and give examples

Hydrophilic molecules such as glucose are water loving, Hydrophobic molecules such a fats are water hating. Amphipathic means a molecule has both hydrophilic and hydrophobic parts, eg a phospholipid

o Memory of water Discuss the ‘memory of water’ Some scientists believe the theory that water can remember the arrangement of the molecules when something was dissolved in it. We call this water memory; this concept is useful in homeopathy as a beneficial solution can be diluted many times yet still have the same effect.

o Describe the structure of carbohydratesDiscuss the genetic modification of potatoes to reduce amylose content so that adhesives can be extracted

Describe the importance of carbohydrates

Draw the ring structure for alpha glucose and beta glucose

Draw the structure of ribose and fructose

Carbohydrates are essential for energy storage eg starch, energy release eg glucose, structure eg chitin and cellulose. Glucose exists in different formats, alpha and beta. Glucose is made up of a 6 membered ring called a pyranose ring. Ribose is made up of a 5 member ring called a furanose ring.

o Describe the formation of polysaccharides

Explain condensation and hydrolysis reactions

State that glycosidic bonds form between monomers during a condensation reaction

Show with examples the formation of a disaccharide and polysaccharide

When two monomers are joined together a bond is formed between them. This involves the removal of water, we call this a condensation reaction. When a molecule is split water is used to do this, we call this hydrolysis. Sucrose is formed for glucose and fructose and is a disaccharide, the bond between them is called a glycosidic bond. Other disaccharides are lactose and maltose. Starch is formed from many glucose molecules being joined together, we call this a polysaccharide cellulose, glycogen and chitin are others.

document.docxConcept Objective Commento Describe the structure of fatty

acids and explain what is meant by mono/poly/unsaturated

Draw the general structure of a fatty acid and glycerol

Show the formation of an ester bond

Identify saturated and unsaturated fatty acid chains

Fatty acids are made up of a glycerol backbone with three fatty acid tails. We call this structure a triglyceride. When a fatty acid joins to the glycerol an ester bond is formed. Fatty acids may be saturated or unsaturated. In saturated fatty acids all of the bonds are occupied with hydrogen and there are no C=C double bonds- it forms a straight chain. In unsaturated fatty acids there are C=C double bonds, these bonds cause a bend (kink) in the chain

o Explain the difference between cis and trans fats

o Discuss the implications of a high fat diet

o Compare contrasting views on fat intake

Define CIS and Trans fat Give examples of CIS and Trans

fats Recognize a CIS and Trans fat and

state their biological implications

CIS fats such as cis-oleic acid have a characteristic kink in their tail and are found naturally. Trans fats such as trans-oleic acid do not have a kink and are produced artificially through hydrogenation. Trans fats are found in fried foods and also in margarine, they allow manufactures to control the consistency of their products. Trans fats have a higher melting point and are more hazardous to health. To differentiate between Cis and Trans fats we locate the C=C bond and look at the position of the hydrogens on either side. If both hydrogens are on the same side, it is a Cis formation and if opposite sides it is trans

o Describe the structure of an amino acid

o Discuss the importance of essential amino acids in the diet

Discuss the biological importance of amino acids

Describe the generic structure of an amino acid

Describe what is meant by an essential amino acid and discuss their importance

Amino acids are essential for the formation of proteins. Each amino acid has an amino group and a distinctive ‘R’ group. Some amino acids are essential and cannot be synthesized by the body. Others can be synthesized and are called no essential amino acids.

o Explain how amino acids are linked to form polypeptides

Describe the formation of a peptide bond

Construct a dipeptide and polypeptide in diagram

When two amino acids are joined by a condensation reaction a dipeptide is formed. The bond that links them is called a peptide bond. When more amino acids are joined a polypeptide is formed

o Link the sequence of amino acids in a protein to genetics

o Link the amino acid sequence of a polypeptide to primary protein structure

o Describe the stages of protein formation

o Link the amino acid sequence to the 3D structure of a protein

Briefly describe the process of transcription sand translation- linking to amino acid sequence

Discuss the importance of the correct amino acid sequence

Give an example of the consequences of a malformed protein

Discuss the primary protein structure

Transcription is the conversion of a section of DNA in to a smaller molecule of mRNA. This molecule can then pass through the nuclear pores to the ribosomes where it is then translated. Translation uses the mRNA as a template to make a protein. Primary proteins are a long chain of amino acids, secondary proteins have hydrogen bonds which form an alpha helix and beta pleated sheet these tend to be structural such as collagen. Tertiary proteins also have disulphide bonds (bridges) and have a 3D shape (globular) eg enzymes, the 3D shape is due in part to the hydrophobic and hydrophyllic amino acid properties, hydrophobic amino acids will face inwards, causing folds in the molecule, this helps to form the shape of the

document.docxo Describe protein structure Describe how the secondary

stage of protein structure arises Describe the tertiary and

quaternary stages of protein structure

Define conjugated protein

active site in an enzyme. Quaternary proteins are formed from more than one peptide or it may be conjugated by the addition of a prosthetic group (haemoglobin and iron). Haemoglobin is a quaternary protein formed from multiple peptide chains (2α chains and 2β). It is a globular protein; it also has a prosthetic heme group (Fe2+) to whic0h oxygen will bind. Each molecule of haemoglobin therefore has four protein chains and each heme group will bind to one oxygen molecule (O2) therefore each molecule of haemoglobin will bind with 4 molecules of oxygen.

o Discuss the influence of polar and non-polar amino acids and the formation of bonds between the R groups

o

Define polar and non-polar in relation to amino acids

Identify polar and non-polar amino acids

Discuss the bonds that form between non-polar and polar R groups

Polar is water loving and will dissolve easily, non-polar is water hating and will not dissolve in water easily. The R groups of amino acids may be polar or non-polar. Positively charge R groups may for hydrogen bonds with negatively charged ones. Non polar amino acids will tend to fold inwards while polar amino acids may be on the outer side of the protein.

o Discuss the universality of protein formation

Explain the importance of proteins in the body

Describe the optimal working conditions of proteins

Discuss the uses of fibrous and globular proteins

Proteins are needed for growth and repair, for enzymes and hormones, for the clotting of blood and for cell transport- amongst other things. Proteins have an optimum working temperature and pH. Above this optimum temperature or at the wrong pH the proteins will be denatured. Fibrous proteins such as collagen are structural and do not dissolve in water. Globular proteins are more likely to dissolve in water and include enzymes.

o Discuss the practicality of proteomics

Define proteome Discuss the individuality of each

proteome Link a person’s proteome to their

genome

Each organism has a unique genetic code (genome) and as a result has a unique proteome- the proteome is the sum of all the proteins produced by an organism.

o Describe the structure of enzymes including their active site

Describe with examples the functions of enzymes in the body

Draw and label the structure of an enzyme

Discuss allosteric enzymes Describe the function of co-

enzymes

Enzymes have many functions in the organism including digestion, respiration and photosynthesis. All enzymes have an active site which is specific to a particular substrate. Allosteric enzymes have an additional binding point/s which other substances may bind to. This may change the shape (conformation) of the active site making the enzyme active or inactive. Chemicals need to activate the enzyme are called co-enzymes.

o Describe the kinetics of enzyme activity

Describe an enzyme as a substance that reduces activation energy

Draw a chart plotting the energy changes that take place during an enzyme reaction

All chemicals reactions need energy to start them off. An enzyme will reduce the amount of energy needed. The substrate binds with the active site forming an enzyme substrate complex, this puts the substrate under stress causing a slight change in its structure. We call this a conformational change.

document.docx Discuss the action of an enzyme

being to bring about a conformational shape of a molecule

o Describe the activity of enzymes Describe the formation of an enzyme/substrate complex

Describe the lock and key theory Describe the theory of induced fit

Each type of enzyme has a unique shape to its active site. Each substrate has a specific and complimentary shape. The two shapes fit like a key fitting a lock. An enzyme substrate complex is formed when the substrate binds to the active site. Another theory is that the enzyme will change the shape of its active site to fit the substrate, we call this change induced fit.

o Discuss the factors that influence enzymes and their rates of reaction

Discuss the optimum conditions needed for enzyme activity

Draw sketch graphs showing the relationship between enzyme activity and the controlling factors

Use a graph of enzyme activity to extract data relating to activity

Enzymes work best at an optimum temperature, above this temperature the active site will change shape (denature). Each enzyme also has an optimum pH outside of which it will denature. The concentration of the enzyme and the substrate will also affect the activity of the enzyme.

o Explain what happens to an enzyme when it is denatured

Describe the specificity of the active site

Explain why changes occur to the active site as it denatures

Describe these changes as conformational and irreversible

When an enzyme denatures the bonds between the different amino acids that maintain the 3D shape will break. This means that the active site loses its specific shape. We say that the active site has gone through a conformational change. This change is irreversible and will prevent the enzyme from working.

o Discuss the action of competitive and non-competitive enzyme inhibitors

Discuss what is meant by enzyme inhibition

Describe with examples the process of competitive enzyme inhibition

State how to overcome competitive inhibition

Describe with examples non-competitive enzyme inhibition

Discuss the types of enzyme inhibition which are reversible and those which are irreversible

Discuss, with examples, what is meant by end product inhibition

Interpret graphs showing enzyme inhibition

In a metabolic pathway the end product in the chain may switch off the first enzyme by binding to its allosteric site. This causes a temporary change in the shape of the active site. We call this end product inhibition. Sometimes a chemical may have a similar shape to the substrate and will temporary bind to the active site preventing the substrate from binding, this results in competitive inhibition. Some substances such as a heavy metal (eg mercury) may bind with a part of the enzyme or with the allosteric site, this causes and irreversible conformational change (change in shape) and stops the enzyme from working we call this non-competitive inhibition.

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o Discuss the functions of enzymes in industry- including the importance of immobilized enzymes

State uses of enzymes in industry Describe how enzymes are

manufactured and harvested in industry

Discuss the advantages of using immobilized enzymes

Enzymes are biological catalysts and speed up biochemical reactions. They have many uses in the body and in industry. They are used in industry to breakdown the pectin in the cell walls of fruits to make the extraction of the juice easier. Enzymes can be produced by a fermenter, bacteria are modified to produce the required enzyme and are grown at the optimum conditions, eg temperature, nutrients, pH and oxygen levels. The enzymes are harvested by filtration methods. It is advantageous to attach enzymes to a non-soluble component as it makes them easier to retrieve.

o Discuss the role of enzyme inhibitors in medicine- include the use of ethanol to combat methanol poisoning

o Discuss the use of fomepizole in the treatment of antifreeze poisoning

o Discuss methods in which enzyme inhibitors are used to treat alcoholism

An example of the use of enzyme inhibitors is methanol poisoning, ethanol is used as a competitor to reduce the effects on the nervous system. Antifreeze contains the chemical Ethylene glycol, this is broken down by the enzyme alcohol dehydrogenase in the liver and causing glycol poisoning. Fomepizole is a competitor for the Ethylene glycol and therefore a competitive inhibitor for alcohol dehydrogenase. Alcoholics may be treated with Disulfiram this inhibits the enzyme aldehyde dehydrogenase, and, as a result, acetaldehyde (a bi-product of the breakdown of ethanol) accumulates. This leads to nausea, hypotension, and flushing.

o Discuss the production of lactose free milk and how advances in enzyme technology benefits some more than others

Note that there are higher occurrences of lactose intolerance in Asia than Europe or America.

Many people throughout the world are intolerant to the lactose that is found in milk. It is possible to breakdown the lactose in to glucose and galactose in the manufacturing process by adding the enzyme lactase. This tends to be an expensive process and is only done in where the costs can be offset by the purchase price. This often excludes people in poorer countries from purchasing the lactose free products.

o Is it appropriate to study a person’s proteome?

o Many metabolic pathways have been traced one reaction at a time- how can looking at part of a reaction give us an understanding of the whole reaction

A person proteome is unique and is directly related to their DNA sequence. Studying the proteome will allow the identification of certain diseases and give a view of the person’s future susceptibility to the disease. Many metabolic pathways are quite complex trying to understand the whole process in a single step may lead to confusion and misunderstanding. By breaking the process down in to smaller steps will allow the process to be mapped more effectively. If we look at individual steps, then then we can deduce the product of previous reactions and the predict the products of reactions in the subsequent steps.

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o Describe the structure of nucleic acids

o Compare and contrast DNA with RNA

Describe the structure of a nucleotide

Describe complimentary base pairings

Identify purines and pyrimidines Describe what is meant by 5’ and

3’

Nucleic acids consist of a phosphate group, sugar and base. There are 4 bases for DNA and they form pairs A-T (2 H bonds) and C-G (3 H bonds). A purine (A, G) is a double ringed structure and a pyrimidine (T-C) is a single ringed structure. When DNA is replicated the complimentary copy will be made in the 5’ and 3’ direction.

Describe the structure of RNA Compare the structure of DNA

with that of RNA Compare the uses or DNA and

RNA

RNA is made up from a phosphate, sugar and base. Uracil substitutes for thymine. RNA differs from DNA as it is a smaller molecule with a ribose sugar rather than the deoxyribose possessed by DNA. DNA acts as a template for the proteins that are manufactured by the body. mRNA is transcribed DNA, tRNA is a carrier molecule used to transport amino acids in the translation process. Each molecule of tRNA consists of a looped strand of RNA and each differs in structure. Each tRNA carries a different amino acid, at the 3’ end of the tRNA molecule there is a triplet code CCA, it is here where the amino acid will bind. To assist with the binding a specific tRNA-activating enzyme is needed along with a molecule of ATP.

o Describe the structure of DNAo Discuss the work of Watson and

Crick and their elucidation of DNA structure

o Discuss the work of Rosalind Franklin and Maurice Wilkins and their contribution to our knowledge of DNA structure through x-ray diffraction

o Discuss the work of Hershey and Chase and how they provided evidence that DNA is genetic material

Discuss the double helix, antiparallel structure of DNA

Discuss how DNA is formed Produce a timeline leading to the

discovery of the structure of DNA

DNA is formed from 2 strands of nucleic acid that are intertwined to form a double helix. The structure of DNA was officially first identified by the scientists Watson and Crick in 1953. DNA is formed by this addition nucleotides using enzymes.

o Describe the structure and function of a nucleosome

o Use molecular visualization software to analyse the association between histone protein and DNA within a nucleosome

1. Define nucleosome2. state the importance of histone

proteins in the formation of a nucleosome

3. State why the packaging of DNA is important in eukaryotes

DNA exists in very long strands and therefore needs to be packaged. If not packaged the mitosis and meiosis would prove difficult. The DNA is packaged by wrapping around a core of histone proteins to form nucleosomes.

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o Discuss the semi-conservative replication of DNA

o Describe the role of helicase on DNA replication

o Describe the role of DNA polymerase on DNA replication

o Discuss how DNA polymerase is only able to add nucleotides to the 3’ end of the primer

o Discuss continuous and discontinuous DNA replication

o Describe how the structure of DNA has led to our understanding of DNA replication

o Describe the action of the enzymes involved in DNA replication

Recap the stage of the cell cycle in which DNA is replicated

Define what is meant by complimentary base pairing

State that DNA replication is semiconservative

Suggest evidence to support that DNA replication is semiconservative

State that DNA replication is an enzyme led process

State the role of helicase in DNA replication

State the role of DNA polymerase I and III in DNA replication

Discuss the action of DNA polymerase

Discuss the role of DNA gyrase State the role of RNA primase in

replication Explain the formation of Okazaki

fragments and the role of ligase in discontinuous DNA replication

State the role of single strand binding proteins in DNA replication

Discuss the connections between the structure of DNA and our understanding of DNA replication

Draw a flow chart to show the action of, Helicase, DNA Polymerase I and III, Primase, single strand binding proteins and Ligase in DNA replication

DNA is replicated in the S phase of the cell cycle. Each strand of existing DNA is replicated semi-conservatively through complimentary base pairing. This means that in each DNA molecule there will be one of the original strands and one new complimentary strand. We can use radioactive isotopes of nitrogen and observing the strands of DNA during mitosis. DNA replication is an enzyme led process and requires the presence of Helicase, Primase and Polymerase.

Leading strand. DNA helicase unwinds the DNA, Primase adds an RNA nucleic acid to the point where replication will begin. Polymerase binds to the DNA and moves along it from the 3’ to the 5’ direction BUT builds the new strand of DNA molecule in the 5’ and 3’ direction.

Lagging strand. The DNA is replicated in sections called Okazaki fragments these fragments are still formed by Polymerase however need to be joined together by DNA ligase.

DNA Polymerase III elongates the DNA by adding a new nucleotide to the 3’ end of the chainDNA Polymerase I removes the RNA primer and replaces it with DNA nucleotideDNA Polymerase II is believed to repair damaged DNA

DNA Gyrase acts to relieve the strain on the DNA strand as it unwinds.

Single stranded binding proteins are used to stabilize the unwound single strands of DNA and prevents them from annealing (rejoining to form a double strand)

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o Discuss the importance of introns, exons, telomeres, regulators and tRNA genes. State the functions of each

State that not all of the DNA on a chromosome will code for a protein

Define introns and exons and discuss their relevance

Explain what is meant by a telomere

Explain the role of regulator genes

Explain the role of tRNA genes

Not all of the DNA will code for protein synthesis there are sections called introns and exons. Exons provide the code for protein synthesis and introns a sections of DNA that do not code for proteins but are important for the regulation of gene expression. A telomere is a section of DNA that is found at each end of the chromosome, it is believed that this portion of DNA protects the integrity of the DNA structure. tRNA genes are sections of DNA that code for the reproduction of tRNA molecules- these are in turn are important for the synthesis of protein.

o Describe the processes involved in transcription

o State that transcription occurs in the 5’-3’ direction

State the need for transcription Describe the process of

transcription State the direction of

transcription as being in the 5’ 3’ direction

State the key enzymes involved in transcription

The molecules of DNA are long and only certain sections are expressed in certain cells. The molecules are too big to pass through the pores in the nuclear membrane. Therefore, shorter chains of mRNA are used for gene expression, these molecules are produced through the process of transcription. During transcription RNA polymerase unwinds the DNA and uses one strand as a template. It starts copying a site called the promoter and will build the molecule in the 5’ 3’ direction. It will stop transcribing the DNA when it reaches the terminator codon. After which the RNA polymerase will detach and the DNA double helix will reform.

o Explain the role of the promoter and terminator in transcription

Identify promoters and terminators as non-coding genes

State the importance of promoters and terminators in transcription

A promoter is the base code that will initiate the transcription process.

o Explain how nucleosomes help to regulate transcription

o Explain how mRNA is modified after transcription

Discuss the need to regulate transcription

Describe the role played by nucleosomes in the regulation of transcription

Explain how mRNA is modified after transcription

Nucleosomes consist of DNA tightly wound around a histone protein core. The protein blocks the transcription of the DNA by covering the promoter until it is needed.

It is important that the RNA produced through transcription is first modified before it leaves the nucleus. The noncoding intron are removed and the exons joined in a process known as splicing. The 5’ end of the molecule is capped and the 3’ end is cleaved and a tail added.

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o Explain how the splicing mRNA increases protein production

State what is meant by the splicing of mRNA

Explain how the splicing of DNA leads to increased protein production

Splicing DNA involves the removal of noncoding introns and the joining of exons. The splicing of the mRNA allows for a single gene to code for more than on protein. This process takes place in the nucleus of the cell.

o Explain how gene expression is regulated

o Link the environment of a cell to gene expression

State what is meant by gene expression

Explain how gene expression is regulated

State the impact that the environment of cells and organisms impact upon gene expression

Certain chemicals act as enhancers and bind to promoters on the DNA enhancing the rate of transcription. Other chemicals act as silencers which bind to the promoters and reduce transcription. The nucleosomes are also important in the regulation of transcription; they will unravel to expose the section of DNA to be transcribed. If the DNA is exposed to certain chemicals or radiation form the environment the rate of transcription can be effected.

o Explain the process of translation

State why mRNA needs to be translated

State the role of ribosomes and tRNA in translation

Identify the key molecules that are involved in translation

Outline the process of translation

Mature mRNA needs to be translated in order for proteins to be produced. The mRNA will leave the nucleus by passing through the nuclear pores. Once in the cytoplasm it will locate a ribosome. Ribosomes are made from two subunits, proteins and ribosomal RNA. The 5’ end (cap) of the mRNA will bind with the small subunit of the ribosome. The small subunit of the ribosome will move along the mRNA towards the 3’ end until it locates the start codon AUG. At this point the large subunit of the ribosome will bind along with a molecule of tRNA- we call this initiation. The ribosome subunits will then move along the mRNA molecule to the next triplet codon (translocation), here a tRNA molecule with the correct anticodon will bind. The enzyme peptidyl transferase will bind the amino acids that are attached to each molecule of tRNA to form peptide bonds. This will continue forming a primary protein chain- we call this elongation. When the ribosomal complex reaches a stop codon (UAG, UGA and UAA), the peptide chain will be released from the ribosomes (termination). The peptide chain will then go through further modifications until it has the correct structure. Note that the large subunit of the ribosome has three binding points E P and A, the tRNA first binds to the A site and then is moved to the P site and finally the E site where it exits, leaving behind the amino acid.

document.docxo Explain how translation is initiatedo Describe how mRNA is translatedo State the role of free ribosomes in

translationo Explain the function of stop codons

State how translation is initiated Describe the action of the start

codon and stop codon State the processes involved in

translation and describe the action of free ribosomes, tRNA and anticodons

Identify the key enzymes for translation

Translation is initiated by the mRNA binding to the small subunit of the ribosome. Once the start codon AUG (this codes for the amino acid methionine) is located translation will begin. Each tRNA molecule has an anticodon and will be attached to a specific amino acid. The tRNA and amino acid with the correct anticodon will bind to the ‘A’ site of the large subunit on the ribosome complex the tRNA will then move to the ‘P’ site and another tRNA binds to the ‘A’ site. The amino acids bound to the tRNA molecules will be joined with peptide bonds. The key enzyme involved in this process will be peptidyl transferase. The tRNA will then move along to the ‘E’ site from where it will be released.

o State the role of membrane bound ribosomes and link to secretions

State that translation also occurs using the membrane bound ribosomes of the endoplasmic reticulum

State the different destinations and functions of the proteins

Ribosomes are found free floating in the cytoplasm and bound to the rough endoplasmic reticulum. Proteins that are formed by free ribosomes are usually used within the cell. Those that are formed and modified by the RER are often secreted from the cell to be used outside of the cell, eg digestive enzymes.

o Explain how translation in eukaryotes differs from that in prokaryotes

Identify the fact that translation must occur in all living organisms

Compare translation in prokaryotes with that of eukaryotes

Discuss differences in the type of ribosomes in prokaryotes and eukaryotes

Discuss why mitochondria may contain the same type of ribosomes as prokaryotes (endosymbiosis)

All organisms require proteins for growth, repair and metabolic function. These proteins are coded for by the DNA. Therefore, in order for the proteins to be synthesized the DNA must first be transcribed and the translated.

In prokaryotes translation id done by 70s ribosomes as opposed to the 80s ribosomes in the eukaryotes. mRNA in prokaryote is polycistronic (codes for several proteins) in eukaryotes it is monocistronic. The process is much faster in prokaryotes, the lifespan of the mRNA is short and unstable. In Eukaryotes the lifespan of the mRNA is stable and longer. In addition, they have different amino acids that are used at the initiation points. It is believed that mitochondria were engulfed by early prokaryotic cells and formed an endosymbiotic relationship with them, these cells then evolved in to eukaryotes.

o Discuss the relevance of triplet codons and anticodons in determining amino acid sequence

Define triplet codon and anticodon

Discuss the relevance of codons and triplet codons

Discuss how amino acids are joined during the formation of proteins during translation

Each 3 bases form a triplet codon. Each triplet codon codes for a specific amino acid. The tRNA molecule with the complimentary codon (anticodon) will bind to the ribosome mRNA complex during the elongation stage of translation. The enzyme peptidyl transferase is used to join the amino acids, forming a polypeptide chain.

o What is meant by junk DNA and explain how this type of

We do not yet know all the functions of the different sections of DNA. There are sections that do not code for proteins and the

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functions are unknown. We call these non-coding sections of DNA ‘Junk DNA’. Some scientists believe that mutation may occur and make the noncoding DNA functional. We call this process exaptation.

o Identify the differences between DNA replication in prokaryotes and eukaryotes?

Prokaryote: Replication takes place in the protoplasm, chromosomes are circular, single stranded, without telomeres, one origin of replication, no histones (Naked DNA), one replication fork

Eukaryote: Replication takes place in the cytoplasm, chromosomes are linear, double stranded, with telomeres, several origins of replication, histone proteins, several replication forks

o Discuss the work of Meslson and Stahl

o

Used isotopic Nitrogen to monitor the replication of DNA, Bacteria were grown in a medium containing 15N, the bacteria were then transferred to a medium containing 14 N, after several generations the bacteria were harvested and the DNA extracted. The DNA was placed in to cesium chloride and centrifuged. The DNA will from bands at three different levels in the solution 15N, 14N and a mixture of the two in the middle. This proved that DNA was replicated semi-conservatively

o Discuss the PCR and its relevance

o

The polymerase chain reaction is a technique that is used to replicate a small sample of DNA several times over. It is useful in forensic science when trying to identify a perpetrator from a mall sample of DNA, during the process DNA goes through cycles of heating and annealing

o Discuss how we have been able to artificially produce human insulin

Insulin is essential to regulate blood glucose levels. Some people are unable to produce sufficient amounts of insulin and therefore need to inject it. In order to meet the global demand for insulin it can be produced by using genetically modified bacteria. In this procedure the DNA from health pancreas cells is removed and

document.docxthe gene for insulin removed through the use of restriction enzymes. Sticky ends are then added to the gene and it is inserted in to a plasmid that has been extracted from an e coli bacterium. Ligase enzymes are used to join the DNA sections together. The plasmid is then reinserted in to the bacterium and a culture is grown in a fermenter. The insulin is then harvested and purified.

o Discuss the role of tRNA activating enzymes and the role of phosphorylation

Each tRNA molecule binds to a specific amino acid. The amino acid first binds to a molecule of ATP. The amino acid is phosphorylated (phosphate added) and the ATP converted to AMP. The ‘charged’ amino acid now binds to the tRNA. When the tRNA binds to the relevant codon on the ribosome mRNA complex the energy from the ‘charged’ amino acid is used to form the peptide bond.

o Identify polysomes in electron micrographs for prokaryotes and eukaryotes

Several ribosomes may act upon the same molecule of mRNA at the same time. We call these polysomes. We can see them on electron micrographs as clusters attached to an mRNA molecule

o Identify the structure of a tRNA molecule with its binding sites

tRNA is made up from a strand of RNA with three loops, one loop has an anticodon which will bind with the triplet codon on the mRNA. At one end of the molecule is a receptor site where an amino acid will bind with an ester bond.

o Describe cell respiration as the controlled release of energy

Stet the cell respiration is the controlled release of energy in the cell

Discuss the need for a controlled release of energy

Discuss the different energy values of food and relate this to the respiratory quotient

Respiration is a biochemical pathway that slowly releases the energy found in food. If the release of energy was not controlled there is a risk that there will be too much energy released, which may result in overheating and wasted energy. Different food substances release different amounts of energy during respiration, we call this the respiratory quotient (RQ). RQ = CO2 eliminated / O2 consumed

The RQ values we need to know are fats 0.7, proteins 0.9 and carbohydrates 1. The study of the RQ allows us to determine which substrates are being used for respiration

o Describe ATP as an immediate energy source in the cell

State the role of ATP in the body Describe the structure of ATP and

relate this to its function Define coupling reaction and link

this to ATP

ATP is considered the bodies energy currency. It is made from up from the genetic base adenine the sugar ribose and three phosphate groups. The bonds between the phosphate groups are considered to be high energy bonds and will release their energy when the bond is broken. This energy can be used in molecular

document.docxsynthesis (anabolism) and for cell transport. The ATP molecule is manufactured from ADP and inorganic phosphate through cellular respiration. ATP is often involved in a coupling reaction where the energy released from one reaction (exergonic) is used to drive a second reaction (endergonic).

o Describe the process of aerobic respiration

Discuss the need for aerobic respiration

Write word and chemical equations for aerobic respiration

Outline the main stages involved in aerobic respiration

State the products of aerobic respiration

During respiration energy is released from an organic substrate. The energy that is released needs to be controlled. Therefore, respiration is the controlled release of energy from an organic substrate (glucose). If the release of energy was not controlled there would be too much energy released during a chemical reaction and much of this would be converted to heat. Aerobic uses oxygen, this type of respiration is important as it has a higher net energy output (38 ATP) than anaerobic respiration (2ATP). The main stages involved in aerobic respiration are, glycolysis, the link reaction, Krebs cycle and oxidative respiration. During aerobic respiration glucose and oxygen are converted in to water and carbon dioxide.

o Describe the structure and function of mitochondria

Sketch a diagram of the mitochondrion

Identify the components and functions of the mitochondrion

State the chemical reactions that take place in the different components of the mitochondrion

The mitochondrion is a double membrane bound organelle containing granules, 70s ribosomes and mitochondrial DNA. The inner membrane is folded to form cristae which increases surface area, the fluid inside of the mitochondrion is called the matrix. The outer membrane separates the contents of the mitochondrion from the contents of the cytoplasm. The inner membrane contains electron transport chains and the enzyme ATP synthase- oxidative phosphorylation takes place here. Between the membranes is the intermembrane space, protons are pumped in to this space for the process of chemiosmosis. The matrix is the place where the Krebs cycle occurs.

o State the key processes involved in cell respiration

o Identify the key steps in glycolysis and state where in the cell it takes place

o State the end products of glycolysis

Identify glycolysis as the initial stage of respiration taking place in the cytoplasm

Outline the breakdown of glucose to pyruvate

Identify the products of Glycolysis Describe the role of oxygen in

aerobic respiration

Glycolysis is the breakdown of a glucose molecule to produce pyruvate. This process takes place in the cytoplasm and requires an investment of 2 ATP molecules. The reaction results in the formation of several intermediary molecules and 4 molecules of ATP are released. The net products of this reaction are 2 molecules of pyruvate and 2 molecules of ATP along with 2 molecules of NADH + H+. If oxygen is present, then the pyruvate will be absorbed by the mitochondrion

o State the key steps involved in the link reaction

Describe the conversion of pyruvate to acetyl CoA

The next stage is the link reaction, where each molecule of the pyruvate is combined with a molecule CoA forming the molecule

document.docxacetyl CoA. This process involves the release of carbon dioxide through oxidative decarboxylation and the reduction of NAD to form NADH + H+. This process takes place in the matrix.

o Discuss the key stages of the Krebs cycle

Outline the stages of the Krebs cycle

Identify the products of the Krebs cycle

The Krebs cycle is also known as the citric acid cycle (TCA) and takes place in the matrix of the mitochondrion, the molecule of acetyl CoA combines with the 4 carbon molecule oxaloacetate, to form a 6 carbon molecule (citrate) and a molecule of CoA. The citrate goes through a series of steps and the oxaloacetate is eventually reformed. The products of the Krebs cycle are. CoA, oxaloacetate, 2 x CO2, 1 x ATP, 3 x NADH + H+, FADH2. Remember that these products are per molecule of acetyl CoA- each glucose molecule produces 2 acetyl CoA molecules.

o Explain the role of NAD and FAD as electron carriers

o Discuss the key stages involved in the electron transport chain

Define oxidative phosphorylation Describe the role of NADH+H and

FADH2 as electron carriers Describe the electron transport

chain

NAD and FAD are referred to as electron carriers. They are involved in the electron transport chain found in the cristae of the mitochondrial inner membrane. The electron carrier delivers electrons to the proteins in the electron carrier chain. The electrons release energy and cause H+ ions to be pumped in to the intermembrane space. The last step of this chain involves the use of the electrons to form water (O + H2) in the matrix. The loss of electrons from the electron carriers is an oxidation reaction and the energy changes as the electrons pass along the chain is used to join inorganic phosphate to ADP, so this process is referred to as oxidative phosphorylation.

o Describe the process of chemiosmosis

Describe the process of chemiosmosis

As the H+ ions are pumped in to the mitochondrial intermembrane space, a H+ concentration gradient is formed. The H+ ions (protons) flow down their concentration gradient through the enzyme ATP synthase. The change in position of the protons releases energy which is used to form ATP from ADP and inorganic phosphate, in the matrix of the mitochondria. This process is referred to as chemiosmosis. This is an example of a coupling reaction.

o Describe the process of anaerobic respiration

Write word and chemical equations for anaerobic respiration

Discuss the need for anaerobic respiration

Describe the key stages of

if oxygen is not available as the final electron acceptor in the electron transport chain, then the electron transport chain will stop. And the pyruvate from glycolysis will no longer be absorbed by the mitochondria. The pyruvate is instead converted to lactic acid lactic acid is a harmful chemical but can be quickly converted to lactate by the enzyme lactate dehydrogenase, which can be

document.docxanaerobic respiration in humans and in yeast

Describe the effects of the bi-products from anaerobic respiration

used as respiratory substrate by the heart (lactate shuttle). This overall process is referred to as anaerobic respiration and is due the incomplete oxidation of the glucose molecule. It is important in the body as it maintains the level of NAD. (NADH is needed top form the lactic acid).

o Describe what happens during anaerobic respiration in humans and in yeast

Describe the chemical reactions that take place during anaerobic respiration in yeast

Describe the conversion of pyruvate to ethanal and then ethanol in yeast

In yeast the pyruvate is converted in to ethanol and then ethanol and carbon dioxide.

o Compare anaerobic and aerobic respiration

Compare the products of aerobic and anaerobic respiration in humans

Compare anaerobic respiration in humans and in yeast

o Describe the pathway taken by alternative substrates to glucose

Compare the energy values of different substrates

State where fatty acids and glycerol enter the respiratory chain

State where amino acids enter the respiratory chain

Discuss the implications of using proteins as a respiratory substrate

The respiratory quotient (RQ) is a measure of the conversion rate between oxygen and carbon dioxide. It can be used to determine the substrate that is being used for respiration. Carbohydrates have the highest RQ followed by proteins and then fats. One reason for this is that the different substrates join the respiratory process at different stages, Deaminated amino acids can form pyruvate and therefore enter the link reaction, fats form acetyl groups when broken down and can then form acetyl CoA, they join the Krebs cycle. The body will use proteins as a substrate for respiration as a last resort as these proteins are important for other functions in the body such as growth, repair, hormones and enzymes.

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o Discuss the ethics of using invertebrates in respirometers

Define respirometer and discuss the ethics of using invertebrates.

A respirometer is a device used to measure the rate of respiration by measuring the consumption of oxygen it uses potassium hydroxide solution to absorb any carbon dioxide that is produced. Traditionally invertebrates such a s maggots have been used for this process as they provide a quick a recordable result. This is now seen as unethical as it causes stress for the animal, they may be harmed when being transferred to the apparatus and can be harmed if they make contact with the potassium hydroxide solution.

o Define energy investment and payout

Energy needs to be invested in order to initiate the glycolysis reaction, however the amount of ATP produced by this reaction (pay out) exceeds the investment. (4ATP v 2ATP)

o Explain how the formation of the chemiosmotic theory led to a paradigm shift

o Explain the difficulties that Peter Mitchell’s chemiosmotic theory faced before it was expected and discuss why the falsification of a theory does not gain immediate acceptance

Chemiosmosis is the production of ATP by the diffusion of H+ ions across the inner membrane of the mitochondrion, using ATP synthase. It was discovered by Peter D Mitchel; in 1961. This this discovery/theory challenged the conventional views towards ATP synthesis. The publishing of his findings caused a change in understanding within the scientific world. We call this change a view a paradigm shift. Initially it was difficult for Mitchel to convince the scientific community to accept his research as it took a completely different approach to conventional theories. Eventually chemiosmosis was accepted and in 1978 Mitchel was awarded the Nobel prize for Chemistry.

o Explain the use of electron tomography to produce images of active mitochondria

Electron tomography is a technique that uses a transmission electron microscope to obtain 3D images of active mitochondria. Electron tomography has revealed that cristae are connected with the inter membrane space between the inner and outer membranes via narrow openings. The shape and volume of the cristae change when mitochondria are active in ways that are still being investigated.

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document.docxo Describe the

structure of a leaf Sketch a diagram of a leaf Identify the function of each layer

found in the leaf Identify the location of

chloroplasts within the leaf Explain how the leaf is adapted

for the efficiency of photosynthesis

The leaf is a flattened organ that absorbs light for photosynthesis. The blade is the flattened part and the petiole is the part that holds the leaf away from the stem. The leaf is made up or several layers, including the waxy cuticle to reduce water loss, the epidermis is a tough layer of cells for protection. The palisade mesophyll layer contains photosynthetic cells that have chloroplasts. The spongy mesophyll cells have some chloroplasts. The air spaces allow the diffusion of gasses. The lower epidermis is again for protection. The guard cells contain chloroplasts they open and close the stomata- tiny pores to allow gas exchange.

o Define photosynthesis as the production of carbon compounds in cells using light energy

State the photosynthesis is the production carbon compounds using light energy

Write a word equation and chemical equation for photosynthesis

State the biological importance of photosynthesis

Describe how the plant utilizes the product of photosynthesis

Photosynthesis is the production of carbon compounds using light energy. It is very important as it fixes the carbon from carbon dioxide forming organic molecules such as glucose. 6H2O +6CO2 C6H12O6 + 6O2. The glucose can then be converted in to starch, fructose, cellulose and amino acids.

o Describe the range of wavelengths found in visible light

o Describe the absorption spectrum for chlorophyll

Define absorption spectrum (400- 700nm)

Define action spectrum Compare the absorption

spectrum with the action spectrum

Note that most of the action spectrum is within the violet/blue range of wavelengths

Light exists in several wavelengths not all of these are absorbed by the plant. Those which are form the absorption spectrum. Out of the wavelengths that are absorbed only some of them are used for photosynthesis- we call this the action spectrum. The violet/blue (400-525nm) and orange/red (625-700 nm) are the two main wavelengths that make up the action and absorption spectrum. It is important to note that not all of the light absorbed by the plant falls on the chloroplasts and will not be used for photosynthesis. Chlorophyll is made up of the following pigments- Chlorophyll a, chlorophyll b and carotenoids. Some organisms (kelp) have additional pigments that allow them to absorb additional frequencies of light improving efficiency. We call these accessory pigments. The pigments in a leaf can be separated by chromatography.

o Describe the structure and

Sketch the structure of a chloroplast and label the

A chloroplast is an organelle surrounded by a double membrane. It consists of flattened sacks bound by pigmented membranes.

document.docxfunction of the chloroplast

components State the function of the key

components Identify the reactions that take

place in each part of the chloroplast

The thylakoids are stacked to form grana. There may be connecting channels between the thylakoids which are called thylakoid membranes. It is in the thylakoids where the light dependent reactions of photosynthesis take place. The inner liquid of the chloroplast is called the stroma., it is here where the light independent (Calvin cycle) takes place. Starch grains, lipid droplets and 70s ribosomes are also found in the stroma.

o Outline the key stages involved in photosynthesis

Briefly outline the stages of photosynthesis

The key stages in photosynthesis are photosystem I, photosystem II, the Calvin cycle and chemiosmosis-Note PSI and PSII refer to the order that they were discovered. - PSII actually happens first. PSI and PSII are light dependent.

o State the key processes of the light dependent reactions and identify the end products

o Identify the thylakoid membranes as being the site of the light dependent reactions

Define light dependent reaction and state the location of this reaction

Define photo activation and electron excitation

Describe the reactions that occur in photosystem 1

Describe the reactions that occur in photosystem 2

Discuss the role of electron transport molecules

State the products of PS1 and PS2

Everything below takes place either in either the thylakoid membrane (PSII, PSI and chemiosmosis) or the inner membrane fluid of the thylakoid (photolysis)Photosystem II (P680- light 680nm), Photons of light are absorbed by electrons in the reaction centre (P680) of the photosystem, these electrons become excited (photo-activated), as they are in this excited state electrons jump from one orbital to another. The excited electrons are then passed along an electron transport chain. Electrons are removed from water, oxygen and H+ ions are formed these electrons replace those lost from the pigment P680. The electrons that passed along the electron chain are now transported to PSI. Photosystem I P700 (700nm). Electrons are received from PSII via an electron carrier, additional photons of light activate the electrons further. Two electrons then pass on through the photosystem until- with hydrogen they are used to reduce a molecule of NAD to form NADH + H. A H+ concentration gradient forms between thylakoid and the stroma, H+ ions move down the concentration gradient from the thylakoid through ATP synthase and into the stroma. This movement causes the formation of ATP from ADP and inorganic phosphate (chemiosmosis)

o Describe the production of oxygen by the

Define photolysis Describe the process of the

photolysis of water

Photolysis is the splitting of water using light. Two photons of light are needed for the removal of 2 electrons from water forming oxygen and 2 hydrogen ions. The electrons are used to replace

document.docxphotolysis of water Explain how electrons obtained

from the photolysis of water replace those lost by the reaction center in PSII

the ones that were lost from PSII from the pigment P680 during photo-activation.

o State the role of reduced NADP

o State how a proton gradient is formed and link this to ATP formation

State the role of NADP in photosynthesis

State of a proton gradient is established between the inner thylakoid space and the thylakoid membrane

Describe the process of ATP generation through chemiosmosis involving the enzyme ATP synthase

NADP is reduced at the end of PSI (in the stroma of the chloroplast) to form NADH + H. This molecule is then used in the Calvin cycle. The formation of this molecule in the stroma and the production of H+ ions in the thylakoid by photolysis maintains a H+ concentration gradient. This concentration gradient results in the flow of H+ ions though a molecule of ATP synthase located in the thylakoid membrane, the energy changes caused by this movement allows the formation of ATP from ADP and inorganic phosphate (chemiosmosis)

o Describe the use of energy to produce carbohydrates from carbon dioxide

Briefly outline the stages in the Calvin cycle

identify where energy is invested in to the Calvin cycle

Identify where carbon dioxide is used in the Calvin cycle

The Calvin cycle takes place in the stroma, the enzyme rubisco is used to fix a molecule of carbon dioxide onto an existing molecule of RuBP (5C), this forms a 6C compound and oxygen. The 6C compound is quickly broken down to form two molecules of PGA, these molecules are then converted to triose phosphate (G3P)- this requires an energy investment of 2ATP and the use of 2 NADPH. Some of these triose phosphate molecules are used to form glucose. Others are converted back in to RuBP an additional ATP molecule needs to be invested at this point. It is important to note that a single cycle will not produce the required products of glucose and RuBP, several cycles are taking place at the same time and the products of 6 cycles are combined to produce the glucose and the RuBP.

o Explain the effects of limiting factors on the rate of photosynthesis

Discuss the factors that may affect photosynthesis

Produce a sketch graph showing the effect of each factor on the

Anything that can affect the rate of photosynthesis is referred to as a limiting factor. Light, temperature and the availability of CO2 are all limiting factors. Each factor may effect different parts of photosynthesis, as photosynthesis occurs in steps the rate of

document.docxrate of photosynthesis

Identify the optimal conditions for photosynthesis and link this to productivity

photosynthesis is determined by the slowest step (rate-limiting step). Low light intensity results in lower ATP and less NADPH thus slows the formation of G3P in the Calvin cycle. At low CO2 levels carbon cannot be fixed to RuBP so the Calvin cycle cannot proceed. At low temperature enzymes such as rubisco are less active, at high temperatures the enzyme may be denatured and therefore stop working, and the Calvin cycle will stop. Ideally plants should be kept in optimum conditions to maximize photosynthesis and therefore growth.

o Link photosynthesis to changes in the Earth’s atmosphere and fossilization

o

Photosynthesis has changed the composition of the atmosphere through the addition of oxygen and the removal of carbon dioxide. More photosynthesis means more biomass. When plants die they may over many years fossilize to form fossil fuels.

o Produce a chromatograph of photosynthetic pigments

Grind a leave using a pestle and mortar and methanol. Place a sample of the extracted pigment on to chromatography paper and place the chromatogram in to a beaker with a small amount of methanol. Observe the separation of chlorophyll a, chlorophyll b and carotenoids.

o Compare paper chromatography with thin layer chromatography

Thin layer chromatography (TLC) uses a glass plate coated in silica gel, it works similar to paper chromatography however can be faster and givers a sharper (clearer) result.

o Discuss the lollipop experiment as performed by Benson and Calvin to elucidate the carboxylation of RuBP

The Calvin cycle- now called the Calvin Benson cycle, it was discovered using the lollipop experiment. Calvin/Benson wanted to track the carbon in CO2 as it was fixed to from a carbohydrate (glucose). They used a flattened flask that looked like a lollipop. The shape of the flask allowed lots of light to pass through to the contents. Inside the flask they used the algae chlorella these are single celled organisms with a single chloroplast, they absorb CO2 quickly and photosynthesize quickly. Calvin/Benson used radioactive 14C as the carbon source, they add dot to the flask and after a short time they removed a sample. They placed the sample in alcohol to kill the algae. They then used two dimensional chromatography to track to position of the 14C.

o Recreate the work of Robert Hill, looking at the decolourisation of

In 1938 Hill performed an investigation to prove that oxygen is released during photosynthesis form the splitting of water (photolysis). He used the chemical DCPIP. Chloroplasts are removed from a plant and placed into a blue solution of DCPIP,

document.docxDCPIP this chemical acts as a reducing agent and replaces the role of

NADP. The DCPIP accepts the electrons from photosystem I and will decolorize when it does. He concluded from the investigation that it was water and not CO2 that is split to form oxygen during photosynthesis.

o Perform an investigation on photosynthesis using hydrogen carbonate indicator and alginate beads with algae (Scenedesmus)

Algae can be immobilized in alginate beads. This allows us to monitor the rate of photosynthesis using hydrogen carbonate indicator. This indicator changes colour in the presence of CO2. It is Purple in low levels of CO2, red in equilibrium with the atmosphere and yellow in high levels of CO2. Placing alginate beads containing algae into yellow indicator will allow us to monitor the rate of colour change.

o Discuss the invention of the artificial leaf and the potential global implications that may arise from this

If we were able to recreate the efficiency of a photosynthesizing leaf to produce electricity, the world energy problems would be solved. The generation of hydrogen using an artificial leaf would provide unlimited amounts of hydrogen that when burned in oxygen will release energy and produce clean water. Imagine the implications of this if we were able to do it efficiently.