Oxygen dissociation curve

Hb responds to low parital pressure of oxygen by dissociating

As tissues use up O2, Hb dissociate more

- S shape shows Hb responds to small decreases in )2 conc. in tissues by giving up alot of O2.

Allostery

- when an O2 combines with haemoglobin

- Hb molecule is slightly distorted

- distortion makes…