Proteins topic 2.4

Question 1

Amino Acids

Answer 1

The monomer of a protein is called an amino acid
* Amino acids are linked together to form polypeptides

Question 2

Peptide bonds

Answer 2

Amino acids are covalently joined by peptide bonds to form
polypeptide chains (requires condensation reactions)

Question 3

Primary Structure

Answer 3

• Order of amino acid sequence
• Formed by covalent peptide bonds

Question 4

Secondary Structure

Answer 4

• Folding into repeat patterns (α-helix or β-pleated sheet)
• By hydrogen bonds between amine and carboxyl groups

Question 5

Tertiary Structure

Answer 5

• Overall three-dimensional arrangement of a polypeptide
• Determined by interactions between variable side chains

Question 6

Quaternary Structure

Answer 6

Presence of multiple polypeptides or prosthetic groups

Question 7

Functions of Proteins

Answer 7

• Structure (collagen, spider silk)
• Hormonal (insulin, glucagon)
• Immunity (immunoglobulins)
• Transport (haemoglobin)
• Sensation (rhodopsin)
• Movement (actin, myosin)
• Enzymatic (Rubisco, catalase)

Question 8

Proteome

Answer 8

The proteome of any given individual will be unique as
protein expression patterns are influenced by a genome

Question 9

Denaturation

Answer 9

Denaturation is a structural change in a protein that results
in the loss (usually permanent) of its biological properties

Question 10

Denaturation can be caused by certain conditions:

Answer 10

Temperature (heat may break structural bonds)
* pH (alters protein charge ➡ changes solubility & shape)