Proteins 2

Question 1

What is the tertiary structure

Answer 1

a 3D folding of the secondary structure. Loops and bends, fold into a globular domain

Question 2

What do we mean by domains?

Answer 2

Protein can be organised into domains, they contribute a specific function to the overall protein

Question 3

5 bonds involved in tertiary structure, stabilise

Answer 3

H
van der vaals
hydrophobic
ionic interactions
disulfide bonds (s-s of cysteine)

Question 4

Quaternary structure

Answer 4

Association of more than one polypeptide. subunits add together to make oligomeric protein. often stabilised by s-s bonds

Question 5

Haemoglobin

Answer 5

carries oxygen, 2 alpha and 2 beta globin chains. Cooperative binding (affinity increases as more O2 binds, due to change in protein structure)

Question 6

What is the conformational change in haemoglobin when it binds to oxygen?

Answer 6

molecular rearrangement of globin chains, causes big structural alignments elsewhere

Question 7

Change in amino acid in Sickle Cell anaemia

Answer 7

Valine instead of glutamic acid

Question 8

collagen structure

Answer 8

3 polipeptide chains wound intpo tropocollagen, microfibril, fibril, fiber

Question 9

What makes tropocollagen strong?

Answer 9

glycine - small, pack in between, every 3 is a turn

proline impose left hand twist and becomes hydroxyproline to form strong hydrogen bonds

Question 10

What residue does crosslinking of collagen fibres involve?

Answer 10

Lysine (lysine derived aldehydes)(lysil oxxidase)

Question 11

Osteogenesis imperfecta

Answer 11

Cysteine instead of glycine. Tropocollagen cannot pack tightly together therefore knock on effect