Biological Molecules

Describe the structure of a collagen molecule and the structure of a collagen fibre.

collagen molecule

collagen fibre

Give the precise name of the monosaccharide labelled D in Fig. 2.1.

On Fig. 2.1, label the glycosidic bond with the letter G.

Write your answer on Fig. 2.1.

On Fig. 2.1, draw a circle around the R group of hydroxylysine and label the circle with the letter R.

Write your answer on Fig. 2.1.

Osteogenesis imperfecta is a disease that results from a deficiency in collagen.

Suggest how a named tissue or structure is affected in a person who has this disease.

Describe three ways, visible in Fig. 2.1, in which the molecule of glycogen differs from the molecule of cellulose.

Glycogen is found in the form of granules in mammalian liver and muscle cells. Fig. 2.2 is a diagram of part of a molecule of glycogen isolated from a glycogen granule.

Explain how the structure of glycogen is related to its function in cells.

Explain how the arrangement of cellulose molecules in plant cell walls is related to their function.

State the name of the bonds that form between glycerol and fatty acids.

When a bond forms between glycerol and a fatty acid, water is a product of the reaction.

State the name given to this type of reaction.

Describe the differences between the fatty acids, X, Y and Z, shown in Fig. 4.1a.

State reasons why triglycerides are described as hydrophobic.

Explain why triglycerides are not suitable as a component of cell surface membranes.

Describe the hydrogen bonding that occurs between the water molecules shown in Fig. 2.1.

Explain the role of hydrogen bonding in maintaining the secondary structure of proteins, such as salivary amylase.

Explain the role of hydrogen bonding in maintaining the tertiary structure of proteins such as salivary amylase.

Outline the importance of water as a solvent in plants.

State the name of the bond in molecule A indicated by the arrow.

Molecule B is described as a saturated fatty acid.

State why molecule B is described as a saturated fatty acid.

Molecule D is a polymer.

State the name of the monomer that is used to synthesise this polymer.

State the letter of the molecule that could be formed during the hydrolysis of a polypeptide.

State the letter of the molecule that forms part of the cell surface membranes of eukaryotic cells.

Molecule A and molecule C dissolve in water. Molecule B does not dissolve in water.

Explain why molecule A and molecule C dissolve in water, but molecule B does not dissolve in water.

Two amino acids are represented in the diagram in Fig. 2.1.

Complete the diagram to show how the two amino acids react together to form a dipeptide.

State what is represented by $R_1$ and $R_2$ in Fig. 2.1.

Amylose and cellulose are polysaccharides.

Fig. 2.2 shows the structure of part of a cellulose molecule.

With reference to Fig. 2.2, state how the structure of a cellulose molecule differs from the structure of an amylose molecule.

Cellulose is the main component of plant cell walls.

Explain why cellulose is suitable as a component of plant cell walls.

The molecule formed from a condensation reaction between fructose and glucose.

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The name of the bond broken when two amino acids are separated by hydrolysis.

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The unbranched polymer consisting only of $\beta$-glucose molecules.

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The reagent used to test for the presence of proteins.

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The molecule produced, in addition to fatty acids, when a triglyceride is hydrolysed.

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can form peptide bonds ...........................

contains ester bonds. ...........................

Name a polymer which can be formed only from many molecules of C.

State one way, visible in Fig. 1.1, in which the part labelled 1 of molecule A differs from the part labelled 2.

Molecule D can form macromolecules with other similar monomers.

These macromolecules have three dimensional shapes held in place by interactions or bonds other than those between adjacent monomers.

Name two of these interactions or bonds.

1. ______

2. ______

which two levels of protein structure are shown

1. ______
2. ______

the name of the structures responsible for holding the two polypeptide chains together.

Many people with diabetes need to take regular injections of insulin. Insulin in the form shown in Fig. 3.1 cannot be taken by mouth as it would be hydrolysed by proteases in the gut.

In the space below, draw a diagram to show how the peptide bond between glutamine 15 and leucine 16 in polypeptide chain A could be hydrolysed and show the products of the hydrolysis.