3 1 Biological Molecules External Assessments Internal Assessments

3. 1: Biological Molecules External Assessments: Internal Assessments: AS – Paper 1 and Paper 2 1. Carbohydrates and lipids exam questions (due: ) A-level – Paper 1 and Paper 3 Required Practicals: 1. Investigation into the effect of a named variable on the rate of an enzyme-controlled reaction Comments: 2. Proteins and enzymes exam questions (due: ) 3. DNA and RNA exam questions (due: ) 4. End of topic test

3. 1. 1: Monomers and Polymers What is the difference between a monomer and a polymer? How does a condensation reaction take place? How does a hydrolysis reaction take place? During which process/group of processes are polymers hydrolysed in the body into monomers? Keywords: Polymers, monomers, polymerisation, monosaccharaides, disaccharides, polysaccharides, soluble, insoluble, isomers, nucleotides, polynucleotide, amino acids, dipeptide, polypeptide, condensation, hydrolysis. What is polymerisation? What are isomers? Draw a general structure of an amino acid, which is an example of a monomer. Draw a diagram of the condensation and hydrolysis reactions between two α-glucose monomers.

3. 1. 2: Carbohydrates Starch, glycogen and cellulose: Key words: How are α-glucose monomers arranged to form the polymers of starch and glycogen? How are β-glucose monomers arranged to form the polymer cellulose? How do the molecular structure of starch, glycogen and cellulose relate to their function? starch; condensation reaction; osmosis; glycogen; cellulose; hydrogen bonds Label the diagram to show the structure of starch: List some of the properties of starch: Draw a diagram to show the structure of cellulose: Explain how its structure relates to its function: What is glycogen and what is it used for?

3. 1. 3: Lipids Triglycerides and Phospholipids Keywords: How are triglycerides formed? Are triglycerides polymers? How does the structure of a phospholipid differ from a triglyceride? Triglycerides, Phospholipids, Saturated, Unsaturated, Hydrophobic, Hydrophilic, R-group, Emulsion test Draw the basic structure of a triglyceride and label the parts. Draw the basic structure of a phospholipid and label the parts. What do the keywords below mean? Hydrophilic: Hydrophobic: Which part of a phospholipid is hydrophilic and which is hydrophobic? Describe the emulsion test, using diagrams.

Carbohydrates and Lipids Exam Questions (due: 1. Name the monosaccharides of which the following disaccharides are composed. ) 2. The diagram shows a triglyceride molecule. (a) (i) Sucrose Monosaccharides ……………. and ……………… (1) (a) (ii) Lactose Monosaccharides ……………. and ……………… (1) (b) Describe how you would use a biochemical test to show that a solution contained a non-reducing sugar, such as sucrose. ……………………………………… (a) Name part A. ………………………………. . (1) (b) With reference to the named parts of the diagram, explain the difference between the terms: …………………………………………………………………………… (i) Triglyceride and phospholipid; ……………………………………… ………. . . . ……………………………. . (2) . . . . . . (ii) saturated and unsaturated. . . . . . . (3) ……………………………………… ………. . . . ……………………………. . (2)

3. 1. 4. 1: General Properties of Proteins Key words: alpha-helix; amino acid; β- How are amino acids linked to for polypeptides – the primary structure of proteins? How are polypeptides arranged to form the secondary structure and then the tertiary structure of a protein? How is the quaternary structure of a protein formed? How are proteins identified? pleated sheet; biuret test; dipeptide; disulphide bonds; ionic bonds; hydrogen bonds; peptide bond; polymerisation; polypeptide; primary structure; protein; quaternary structure; secondary structure; tertiary structure; Draw and label an amino acid: What is the test for proteins and what results would you expect? Label the diagram to show the formation of a polypeptide bond:

3. 1. 4. 1: General Properties of Proteins Key words: alpha-helix; amino acid; β- How are amino acids linked to for polypeptides – the primary structure of proteins? How are polypeptides arranged to form the secondary structure and then the tertiary structure of a protein? How is the quaternary structure of a protein formed? How are proteins identified? pleated sheet; biuret test; dipeptide; disulphide bonds; ionic bonds; hydrogen bonds; peptide bond; polymerisation; polypeptide; primary structure; protein; quaternary structure; secondary structure; tertiary structure; Draw the primary structure of a protein: Draw the secondary structure of a protein: Draw the tertiary structure of a protein: Draw the quaternary structure of a protein:

3. 1. 4. 2: Enzymes Enzyme action Key words: How do enzymes speed up chemical reactions? How does the structure of enzyme molecules relate to their function? What is the lock and key model of enzyme action? What is the induced-fit model of enzyme action? activation energy; catalyst; enzyme-substrate complex; induced fit; lock and key; substrate; Draw a diagram to explain the lock and key model of enzyme action: How does an enzyme’s structure relate to its function? Draw a diagram to explain the induced-fit model of enzyme action: Draw a sketch graph to show enzymes speed up a reaction:

3. 1. 4. 2: Enzymes Factors affecting enzyme action How is the rate of an enzyme-controlled reaction measured? How does temperature affect the rate of an enzyme-controlled reaction? How does p. H affect the rate of enzyme-controlled reaction? How does substrate concentration affect the rate of reaction? How does temperature affect the rate of an enzyme-controlled reaction? How does substrate concentration affect the rate of an enzyme-controlled reaction? Key words: active site; denature; optimum; p. H; substrate concentration; temperature How does p. H affect the rate of an enzymecontrolled reaction?

3. 1. 4. 2: Enzymes Enzyme inhibition Key words: How do competitive inhibitors and non-competitive inhibitors affect the active site? What is enzyme inhibition? competitive inhibitor; end-product inhibitor; irreversible; noncompetitive inhibitor How do competitive inhibitors affect the active site? Use diagrams in your explanation. How do non-competitive inhibitors affect the active site? Use diagrams in your explanation.

Proteins and Enzymes Exam Questions (due: 1. A protein is formed from 300 amino acids. The diagrams show the primary, secondary and tertiary structures of this protein. ) 2. The graph shows the effect of substrate concentration on the rate of an enzyme-controlled reaction. (i) Explain what causes the secondary structure to differ in length from the primary structure. …………………………………… (a) (i) Describe what the graph shows about the effect of substrate ……………………………………. (1) concentration on the rate of this enzyme-controlled reaction. (ii) Explain what is meant by the tertiary structure of a protein. ………………………………………………………………………………. (1) ……………………………………… (iii) Heating may affect the tertiary structure of a protein. Explain how. …………………………………(2) a) (ii) What limits the rate of this reaction between points A and B? Give the evidence from the graph for this. ……………………………………………………………………………… ………………………………………………………………………………. . (2) …………………………………(2)

3. 1. 5. 1: Structure of DNA and RNA Key words: cytosine; thymine; adenine; guanine; Structure of DNA What are the components of DNA? How are these components arranged within the DNA double helix? What is the function of DNA? Draw and label a nucleotide phosphate; deoxyribose sugar; condensation reaction; mononucleotide; dinucleotide; polynucleotide; complementary; double helix; antiparallel; hydrogen bonds List the four bases under the following columns: Purines Pyrimidines Explain how DNA forms a double helix using the key words above: Draw and label how two nucleotides condense to form the start of a polynucleotide strand Explain how to the structure of DNA is linked to its function: 1. 2. 3.

3. 1. 5. 1: Structure of DNA and RNA Structure of RNA Key words: What are the components of RNA? How and where is RNA used in cells? adenine; thymine; guanine; cytosine; uracil; deoxyribose; r. RNA; m. RNA; t. RNA How is the structure of RNA different from that of DNA? Name and explain 3 types of RNA and how they are important:

3. 1. 5. 2: DNA Replication of DNA What happens during DNA replication? How is a new polynucleotide strand formed? Why is the process of DNA replication called semi-conservation? Explain the semi conservative model of DNA replication using the key words above: Key words: nuclear division; cell division; DNA helicase; DNA polymerase, hydrogen bonds, nucleotides, complementary

3. 1. 5. 2: DNA Replication Experimental Evidence for Semi-Conservative Replication What happens during DNA replication? How is a new polynucleotide strand formed? Why is the process of DNA replication called semi-conservation? Key words: nuclear division; cell division; DNA helicase; DNA polymerase, hydrogen bonds, nucleotides, complementary Explain the experimental evidence for semi conservative replication of DNA using the diagram below.

DNA and RNA Exam Questions (due: The diagram shows part of a DNA molecule. ) Name the parts of the diagram labelled C, D and E. Part C……………………. Part D……………………. Part E…………………. . . (3) In a piece of DNA, 34% of the bases were thymine. Complete the table to show the name and percentages of the other bases. (2) DNA is a polymer. What is the evidence from the diagram that DNA is a polymer? (1) Name of base Percentage Thymine 34 34

DNA and RNA Exam Questions (due: The diagram shows the bases in a r. RNA molecule. In addition to A, U, C and G there are other bases present in t. RNA. The other bases are shown by the letter D. ) DNA and t. RNA are both polynucleotide strands. Other than their nucleotide structure, give one similarity between the structures of DNA and t. RNA (1) Other than the difference in some of the bases, give three ways in which the structure of DNA is different from t. RNA. (3) 1 2 Which of the bases also occur in DNA? (1) 3

DNA and RNA Exam Questions (due: ) Describe how DNA is replicated (6) Total mark for DNA and RNA Exam Qs: /17

3. 1. 6: ATP What are the components of ATP? How is ATP broken down? How is ATP formed? Label the diagram of an ATP molecule: How is ATP resynthesised after hydrolysis? Key words: adenosine triphosphate; adenine; ribose; inorganic phosphate; ATP hydrolase; hydrolysis; phosphorylate; condensation; respiration. Use a labelled diagram to explain the hydrolysis of ATP:

3. 1. 7: Water is a major component of cells. It has several properties that are important in biology Explain the role of water, with examples, in terms of: Keywords: metabolite; hydrogen bonding; dipolar; specific heat capacity; latent heat of vaporisation; cohesion; surface temperature Large latent heat of vaporisation: Role as a metabolite: Strong cohesion between the molecules: Role as a solvent: Has a high specific heat capacity: