Transport of oxygen

Question 1

Haemoglobin

Answer 1

> oxygen is transported in red blood cells which contain the protein Haemoglobin
O combines to form oxyhaemoglobin
Complex protein with 4 sub units containing a haem group
the haem group contains an iron ion which can hold a single oxygen molecule
each haemoglobin can carry 4 O molecules

Question 2

Transport of oxygen

Answer 2

> at a low partial pressure of oxygen haemoglobin does not associate with oxygen as the haem groups are near the centre of the molecule
as oxygen tension rises the saturation of haemoglobin increases
eventually an oxygen molecule associates with one of the haem groups
causes conformational shape change
allowing more oxygen molecules to associate

Question 3

Fetal haemoglobin

Answer 3

> has a higher affinity for oxygen than adult H
curve is to the left of adult
because fetal HB must be able to associate with O2 when oxygen tension is low