Proteins 2

• Heat - breaks weak bonds
• pH - affects hydrogen bonding and electrostatic interactions
• Detergents and organic solvents - hydrophobic bonds
• Chaotropic agents eg urea - form hydrogen bonds with amino acids and disrupt existing hydrogen bonding and hydrophobic interactions

Yes, as long as the 1y sequence (which dictates the protein's structure) is unaffected

Three

Glycine - it is the only amino acid small enough to fit into the tight centre

Scurvy is caused by a vitamin C deficiency.  Vitamin C is a co-enzyme for prohydroxylase.  Low levels of vitamin C means there is insufficient hydroxylation of proline which means there are fewer hydrogen bonds able to form and the collagen molecules become more unstable.

A mutation in the Gly codon meaning glycine is not present in every 3rd position in collagen.

The structure of proteins change from their normal, globular form (alpha helix) to a non functional fibrous form (beta sheets).

Chaperone proteins are involved in changing proteins back from the fibrous form into the globular form.  Their loss of function would mean less proteins are converted back into the globular form which would allow the accumulation and aggregation of the fibrous form - which disrupts neurological function.

• a) low affinity
• b) high affinity

• Allosteric regulators bind at other sites and they alter the affinity of the subunit for the ligand.
• Positive allosteric regulators increase ligand affinity
• Negative allosteric regulators inhibit ligand affinity