12.11 Haemoglobin

Question 1

When does oxygen get transported by haemoglobin and not simple diffusion?

Answer 1

For the transport of organisms that are too large for simple diffusion

Question 2

Affinity definition

Answer 2

Chemical attraction

Question 3

Saturation definition

Answer 3

Full of oxygen (full load)

Question 4

Loading definition

Answer 4

Gaining oxygen onto haemoglobin

Question 5

Unloading definition

Answer 5

Unloading oxygen in haemoglobin to tissues

Question 6

Partial pressure definition (pO2)

Answer 6

The proportion of oxygen in a mixture of gases or a solution

Question 7

Where is saturated haemoglobin found?

Answer 7

After it has been to the lungs

Question 8

Where is unsaturated haemoglobin found?

Answer 8

Before it has passed through the lungs

Question 9

What is unsaturated haemoglobin needed for?

Answer 9

Aerobind respiration to produce ATP

Question 10

What is the structure off haemoglobin?

Answer 10

A quaternary structure with four polypeptide chains, each containing a haem group.

Question 11

What affinity does haemoglobin haver to oxygen?

Answer 11

A high affinity

Question 12

How many molecules of oxygen can each haemoglobin combine with?

Answer 12

Four oxygen molecules

Question 13

When oxygen and haemoglobin combing, what is it called?

Answer 13

Oxyhaemoglobin

Question 14

Percentage saturation of haemoglobin equation

Answer 14

Oxygenated / haemoglobin x 100

Question 15

Why is the first oxygen molecule important?

Answer 15

The first oxygen molecule alters the tertiary structure, making the binding site easier to bind to oxygen

Question 16

The more the more the more

Answer 16

The more oxygen is in the blood, the more oxygen is loaded onto haemoglobin, the more saturated there haemoglobin is

Question 17

What is the name of the partial pressure curve?

Answer 17

Sigmoid curve

Question 18

What is the partial pressure of oxygen in capillaries?

Answer 18

High

Question 19

What is the partial pressure of oxygen in respiring tissues?

Answer 19

Lower

Question 20

Why is the partial pressure of oxygen in respiring tissues lower?

Answer 20

The haemoglobin has a lower affinity to oxygen as the partial pressure is lower o the oxyhaemoglobin starts to break down and unloads the oxygen more easily

Question 21

What is the oxygen in the tissues used for?

Answer 21

Aerobic respiration

Question 22

What is the effect of increased respiration on oxygen dissociation?

Answer 22

• Tissue cells respire quickly, using up the dissolved O2 in the surrounding fluid
  -This reduces the partial pressure to a lower level
  The oxygenated blood arriving with fully saturated haemoglobin will unload more oxygen more easily into the tissue cells
• The haemoglobin therefore, will have an even lower affinity to oxygen

Question 23

What is the Bohr shift?

Answer 23

The sigmoid curve shifts to the right

Question 24

What is the effect of increased carbon dioxide concentration on the sigmoid curve?

Answer 24

The affinity to oxygen is even lower
The partial pressure to CO2 increases, saturation of haemoglobin decreases
Causing the dissociation curve to shift to the right

Question 25

Why does haemoglobin have a lower affinity to oxygen at high levels of CO2?

Answer 25

When CO2 dissolves in the blood, it makes it more acidic Haemoglobin is a protein, so the change in pH alters the tertiary structure of the haemoglobin Therefore oxygen can't bind as easily

Question 26

Heat from respiration helps mammals to maintain a constant body temp Explain the relationship on the sigmoid curve

Answer 26

Smaller mammals have a larger SA:V ratio, therefore more heat lost per unit body mass and a greater rate of respiration Oxygen required for aerobic respiration Haemoglobin releases more oxygen

Question 27

What can cause differences in haemoglobin affinities?

Answer 27

Genetic differences Mutations

Question 28

What type of haemoglobin is found in places of high altitude?

Answer 28

Haemoglobin has a higher affinity to oxygen Curve shifted to the left Becomes fully saturated at lower partial pressure Similar to the fetus curve

Question 29

What type of haemoglobin curve is found in animals like cheetahs?

Answer 29

Haemoglobin has a lower affinity to oxygen Curve shifts to the right Oxygen dissociates from haemoglobin more easily Oxygen more readily available in respiring tissue cells

Question 30

Metabolism definition

Answer 30

Rate of cellular reactions

Question 31

The oxygen dissociation curve of a foetus is to the left of the mothers, explain the advantage

Answer 31

Higher affinity to oxygen at the same partial pressure Oxygen moves from the mother to foetus more easily

Question 32

Explain how oxygen is loaded, unloaded and transported in the blood

Answer 32

- Haemoglobin carries oxygen in red blood cells - Loading takes place in the lungs at a high partial pressure - Unloading takes place in respiring tissue cells at a low partial pressure Unloading linked to carbon dioxide concentration