Hemoglobin

Question 1

Hill equation

Answer 1

log(Y/1-Y) = hlog[S] - logK_D

Where KD is the dissociation constant

Y = the fraction of enzyme with substrate bound

Y/1-Y = the fraction of binding sites which are occupied for an enzyme binding substrate

Question 2

Three cases of hill coefficient

Answer 2

1) If h=1, the enzyme exhibits no cooperativity
2) If h=n then the enzyme exhibits perfect cooperative behavior

In this case only enzyme fully bound to substrate or completely unbound would be present. This is never seen in reality

3) If 1<h>
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Question 3

bohr effect

Answer 3

Exchange of oxygen for carbon dioxide and protons. At low oxygen partial pressure, hemoglobin exchanges oxygen for Carbon dioxide and a proton, which lowers the pH. pH is lower in the tissues, so oxygen release occurs here.

Question 4

BPG effect on Hemoglobin

Answer 4

• BPG binds very tightly to deoxy-hemoglobin.
• BPG binds hemoglobin when there is less oxygen available, like in high altitudes.
• binding of BPG promotes release of oxygen

Question 5

pH effect on hemoglobin

Answer 5

• Lower pH promotes release of oxygen
• Increased CO₂ levels reduce blood pH

Question 6

R state of hemoglobin

Answer 6

Stands for relaxed state. This is the state that oxygen is bound in

Question 7

T state of hemoglobin

Answer 7

Stands for tight. This is the conformation in which hemoglobin does not bind oxygen