MGD S1

Question 1

What are the key features of an alpha helix?

Answer 1

Right-handed helix, 3.6 amino acids per turn, 0.54 nm pitch, regular repeating secondary structure, Hydrogen bonding

Question 2

Define “amphipathic”

Answer 2

A molecule which has both a polar (hydrophilic) and non-polar (hydrophobic) end

Question 3

What are the key features of a beta sheet?

Answer 3

Extended conformation, can be parallel or antiparallel

Question 4

Which amino acid residue supports disulphide bond formation?

Answer 4

Cysteine

Question 5

Define “Isoelectric Point”

Answer 5

The pH at which a protein has no overall net charge

Question 6

What are the key features of a peptide bond?

Answer 6

Planar, restricted rotation, trans orientation

Question 7

Define “zwitterion”

Answer 7

A zwitterion is a molecule that has both positively and negatively charged groups

Question 8

What bond types are involved in primary protein structure?

Answer 8

Covalent (peptide)

Question 9

What bond types are involved in secondary protein structure?

Answer 9

Hydrogen

Question 10

What bond types are involved in tertiary protein structure?

Answer 10

Hydrogen, van der waals, hydrophobic interactions, covalent (disulphide), ionic interactions

Question 11

What bond types are involved in quaternary protein structure?

Answer 11

Hydrogen, van der waals, hydrophobic interactions, covalent (disulphide), ionic interactions

Question 12

What is the difference between a homomeric and a heteromeric protein?

Answer 12

Homomeric proteins are made up of multiple identical subunits, but heteromeric are comprised of different subunits