A6 Haemoglobin

Question 1

What is the role of haemoglobin?

Answer 1

To load or unload oxygen

Question 2

What is the word used to remember the key words to do with haemoglobin?

Answer 2

P - partial pressure
A -Affinity
L- Load or unload
S- Saturated or unsaturated

Question 3

Describe the role of haemoglobin in the respiring cells.

Answer 3

There is a low partial pressure of oxygen therefore there is a low affinity of oxygen so haemoglobin unloads more readily to the cells. Haemoglobin is also less saturated as it has fewer oxygen molecules loaded

Question 4

Describe the role of haemoglobin in the lungs.

Answer 4

There is a high partial pressure of oxygen therefore a high affinity so haemoglobin loads more oxygen more readily and haemoglobin is more saturated as it has lots of oxygen molecules loaded

Question 5

Write the equation of haemoglobin and oxygen to form oxyhaemoglobin.

Answer 5

Hb + 4O2 ⇌ HbO8

Question 6

What does it mean if the line in a graph is right shifted?

Answer 6

At a certain pp02 haemoglobin has a low affinity for oxygen and therefore is less saturated. Haemoglobin unloads oxygen more readily to respiring cells

Question 7

What is the s shape that is shown on a graph for haemoglobin called?

Answer 7

Sigmoidal curve

Question 8

What is an example to use on the right shifted line?

Answer 8

Humming bird as it needs lots of muscular contraction whilst its flying therefore lots of respiration to release ATP. Or Field mouse as it has a high metabolic rate due to its high surface area so it loses heat at a higher rate

Question 9

What does it mean if the line on a graph is left shifted?

Answer 9

At lower pp02 haemoglobin has a higher affinity for oxygen so it becomes more saturated and it loads oxygen more readily forming oxyhaemoglobin.

Question 10

What is an example to use on the lift shifted line?

Answer 10

Lungworm as they live in low pp02 so their haemoglobin needs a high affinity for oxygen

Question 11

Describe the Bohr effect.

Answer 11

The Bohr effect refers to the shift in the oxygen dissociation curve caused by changes in the concentration of carbon dioxide or oxygen or the pH of the environment.

Question 12

How is Carbonic acid formed?

Answer 12

When the two products of respiration, carbon dioxide and water react during a reversible reaction

Question 13

What does carbonic acid do in the body?

Answer 13

It lowers pH of blood plasma

Question 14

What is the pH of blood like when the rate of respiration is high?

Answer 14

The pH of the blood is very low

Question 15

What happens when there is a low or high pH in the blood?

Answer 15

A protein will change shape of its tertiary structure (exposing haem group binding sites). This lowers the affinity of haemoglobin for oxygen.

Question 16

Which way is the sigmoidal curve shifted in a foetus?

Answer 16

The curve is left-shifted so the haemoglobin has a high affinity in low pp02 so therefore loads oxygen more readily from the mothers blood