Enzyme Regulation

Question 1

factors causing T to R transition in haemoglobin

Answer 1

1. Iron (II) atom moves into plane of haem after oxygen binding. 2. Helix containing His ligand moves. 3. Movement of helix alters interface between αβ pairs. 4. αβ pairs slide & rotate upon formation of R state

Question 2

allosteric regulation of haemoglobin

Answer 2

negative regulators that promote oxygen release: 2,3-bisphosphoglycerate (in RBC), CO2 & H+ (which are important for delivering oxygen to rapidly metabolizing tissues)

Question 3

increased level of __ allows acclimation to high altitudes

Answer 3

2,3-bisphosphoglycerate

Question 4

when binding curve is further to left…

Answer 4

it has higher affinity for binding oxygen

Question 5

decreasing pH (Bohr effect) & increased CO2 levels…

Answer 5

promote oxygen release. (protonation of His by lowering pH promotes T form of deoxyhaemoglobin