Carriage of oxygen

What do RBCs contain?

Haemoglobin (globular protein) and oxyhemoglobin (O2 and haemoglobin)

Where are RBCs made?

Bone marrow

What does O2 dissolve in?

Blood plasma, but not in sufficient amounts to provide for cells needs

What does each haem subunit contain?

An iron atom, each bonds with 1 O2 molecule

What does each haemoglobin molecule contain?

4 haem groups each able to bond with 1 molecule of O2

How many O2 molecules can each haemoglobin molecule carry ?

4 O2 molecules

What is dissociation?

Release of O2 from haemoglobin

What is partial pressure?

Pressure that O2 exerts within a mixture of gases used as a measure of amount of O2 in kPa

What is affinity?

Attraction for..

What happens at the lungs?

O2 levels in RBC are low so O2 binds with haemoglobin to form oxyhaemoglobin

What happens at tissues?

O2 levels in body cells are low, O2 diffuses down conc gradient from erythrocyte into body cells

What do oxygen dissociation curves show?

The rate that O2 associates and disassociates with haemoglobin at diff partial pressures of O2

When is haemoglobin referred to as saturated?

When all 4 O2 binding sites are taken up w/ O2

What happens when haemoglobin has a high affinity for O2?

It binds easily and dissociates very slowly

What happens when haemoglobin has a low affinity for O2?

It binds slowly and dissociates easily