Proteins

Question 1

Haemoglobin

Answer 1

a red pigment that carries oxygen and gives erythrocytes their colour

Question 2

Amino acids

Answer 2

the building blocks of proteins consisting of an amino group -(NH2) and a carboxyl group -(COOH) attached to a carbon atom and an R group that varies between amino acids

Question 3

Peptide bonds

Answer 3

bonds formed by condensation reactions between amino acids.

Question 4

dipeptide

Answer 4

Two amino acids joined together by a peptide bond

Question 5

disulfide bond

Answer 5

a strong covalent bond produced by an oxidation reaction between sulfur groups in cysteine or methionine molecules, which are close together in the structure of a polypeptide.

Question 6

Fibrous proteins

Answer 6

proteins that have long, parallel polypeptide chains with occasional cross-linkages that produce fibres; they have little tertiary structure

Question 7

denaturation

Answer 7

the loss of the 3D shape of a protein (e.g caused by changes in temperature or pH)

Question 8

Globular proteins

Answer 8

large proteins with complex tertiary and sometimes quaternary structures, folded into spherical (globular shapes)

Question 9

Hydrophobic

Answer 9

a substance that tends to repel water and will not mix with or dissolve in water

Question 10

Hydrophilic

Answer 10

a substance with an affinity for water that will readily dissolve in or mix with water

Question 11

Colloid

Answer 11

a suspension of molecules that are not fully dissolved

Question 12

Prosthetic group

Answer 12

the molecule incorporated in a conjugated protein

Question 13

conjugated proteins

Answer 13

protein molecules joined with or conjugated to another molecule called a prosthetic group.

Question 14

Lipoproteins

Answer 14

conjugated proteins with a lipid prosthetic group

Question 15

glycoproteins

Answer 15

conjugated proteins with a carbohydrate prosthetic group

Question 16

Proteases

Answer 16

protein-digesting enzymes