oxygen disassociation and the Bohr effect

Question 1

what does an oxygen dissociation curve show?

Answer 1

a curve on a graph that shows how saturated haemoglobin is with oxygen at any given partial pressure.

Question 2

what does it mean when haemoglobin is saturated with oxygen?

Answer 2

how much oxygen is bound to haemoglobin (maximum amount of oxygen it can bind with)

Question 3

describe the loading, transport and unloading of oxygen in areas with low pressure (respiring tissues)

Answer 3

Hb has a low affinity for oxygen so oxygen unloads with Hb so saturation percentage is low.

Question 4

when is oxygen loaded and unloaded?

Answer 4

oxygen is loaded in regions with high partial pressure of oxygen (lungs) and is unloaded in regions with low partial pressure of oxygen (respiring tissues)

Question 5

describe the loading, transport and unloading of oxygen in areas with high pressure (lungs/alveoli)

Answer 5

Hb has a high affinity for oxygen so oxygen loads with Hb so saturation percentage is high.

Question 6

explain how the cooperative nature of oxygen binding results in an
s-shaped oxyhemoglobin dissociation curve.

Answer 6

oxygen is difficult to bind but once the first oxygen binds, the quaternary structure of Hb changes, making further binding of oxygen easier.

Question 7

why does haemoglobin have different properties at different partial pressures?

Answer 7

due to cooperative binding