Proteins

Question 1

Amino acids

Answer 1

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

Question 2

Peptide bond

Answer 2

A peptide bond is the bond formed by condensation reactions between amino acids.

Question 3

Polypeptide

Answer 3

A polypeptide is a long chain of amino acids joined by a peptide bond.

Question 4

Fibrous proteins

Answer 4

Fibrous proteins are proteins that have long, parallel polypeptide chains with occasional cross-linkages that form into fibres, but with little tertiary structure.

Question 5

Disulfide bond

Answer 5

A disulfide bond is a strong covalent bond formed as a result of oxidation reaction between sulfur groups in cysteine or methionine molecules, which are close together in the structure of a polypeptide.

Question 6

Globular proteins

Answer 6

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

Question 7

Haemoglobin

Answer 7

A haemoglobin is a large conjugated protein involved in transporting oxygen in the blood, and gives the erythrocytes their red colour.

Question 8

Collagen

Answer 8

Collagen is a strong fibrous protein with a triple helix structure.

Question 9

Denaturation

Answer 9

Denaturation is the loss of the 3D shape of a protein, e.g as a result of changes in temperature or PH.

Question 10

Prosthetic group

Answer 10

A prosthetic group is the molecule that is incorporated in a conjugated protein.

Question 11

Glycoprotein

Answer 11

A glycoprotein is a protein with carbohydrate prosthetic group.

Question 12

Protease

Answer 12

A protease is a protein-digesting enzyme.

Question 13

Lipoprotein

Answer 13

A lipoprotein is a protein with a lipid prosthetic group.