Evolution & Protein Structure

Question 1

Describe primary protein structure.

Answer 1

The sequence of amino acids, e.g. Gln-Asn-Gly-Leu-Asp-

Question 2

Describe secondary protein structure.

Answer 2

How the chain of AAs coils up into helices, loops and sheets.

Question 3

Describe tertiary protein structure.

Answer 3

The 3D folding of the secondary structures.

Question 4

Describe quaternary protein structure.

Answer 4

Some proteins are made of 2 or more separate subunits (e.g. haemoglobin, a tetramer).

Question 5

Define ‘protein domains’.

Answer 5

Domains are distinct functional and/or structural units in a protein. Usually they are responsible for a particular function or interaction, contributing to the overall role of a protein.

Question 6

Give examples of sequence features.

Answer 6

• active sites
• binding sites
• post-translational modification (PTM) sites
• repeats.

Question 7

What are hox genes?

Answer 7

‘Master switch’ proteins that control development in all metazoans. They are all homologous.

Question 8

What types of mutations may occur in the coding DNA?

Answer 8

Synonymous and non-synonymous.

Question 9

Define synonymous mutations.

Answer 9

Mutations which occur in the coding sequences of DNA that do not alter an amino acid.

Question 10

Define non-synonymous mutations.

Answer 10

Mutations which occur in the coding sequences of DNA that alter an amino acid.