Transport of gases in the blood

Question 1

What is the purpose of haemoglobin?

Answer 1

To increase the carrying capacity of oxygen of the blood

Question 2

What is a conjugate protein?

Answer 2

A protein with non-polypeptide chains in its structure

Question 3

Describe the structure of haemoglobin

Answer 3

Made of 4 subunits

Each subunit has a polypeptide chain with a haem group attached to it

Question 4

Describe the structure of a red blood cell

Answer 4

Biconcave
No nucleus
Thin

Question 5

How many oxygen molecules can a haemoglobin molecule carry?

Answer 5

4

Question 6

What does allosteric mean?

Answer 6

When the shape of a molecule is changed by another molecule binding to it

Question 7

Explain how easily oxygen is loaded onto a haemoglobin molecules

Answer 7

First one is difficult
Next two are easy
Last one is difficult

Question 8

What is the shape of the oxygen dissociation curve of haemoglobin

Answer 8

S shape

Question 9

What is the Bohr effect?

Answer 9

The effect of CO2 on the O2 dissociation curve of haemoglobin

Question 10

Explain how carbon dioxide is loaded onto haemoglobin

Answer 10

CO2 diffuses in
Reacts with water in the presence of carbonic anhydrase
Forms carbonic acid - dissociates into H+ and hydrogencarbonate ion
H+ reacts with oxyhaemoglobin and releases oxygen
HCO3- leaves, Cl- enters

Question 11

What is the enzyme which catalyses the reaction between CO2 and O2?

Answer 11

Carbonic anhydrase

Question 12

What is the purpose of the chloride shift?

Answer 12

To stabilise the charge inside a red blood cell

Question 13

How does the Bohr effect shift the curve?

Answer 13

To the right

Question 14

How does foetal haemoglobin shift the curve

Answer 14

To the left

Question 15

How does myoglobin shift the curve?

Answer 15

To the left

Question 16

Describe the structure of myoglobin

Answer 16

One polypeptide chain attached to one haem group

Question 17

Does foetal haem. have a high or low affinity for O2?

Answer 17

High

Question 18

Give an adaptation of a pregnant woman to ensure the fetus gets enough O2?

Answer 18

Blood flows in the opposite way to the placenta so there’s a counter current multiplier

Question 19

What is an advantage of myoglobin?

Answer 19

Good store of oxygen bc doesnt release oxygen until partial pressure is hella low

Question 20

What can be said about the affinity of a substance for something if the curve is to the left?

Answer 20

Has a high affinity for oxygen

Question 21

What can be said about the affinity of a substance for something if the curve is to the right?

Answer 21

Has a low affinity for oxygen