2. Haemoglobin

Question 1

What is the role of haemoglobin?

Answer 1

Found in red blood cells to carry oxygen around the body.

Question 2

Give examples of where haemoglobin?

Answer 2

Earthworms.
Starfish.
Some insects/plants/bacteria.

Question 3

Give examples of a mass transport system?

Answer 3

Circulatory system.

Question 4

What is haemoglobin made up of?

Answer 4

Is a large protein with a Quaternary structure.
Its made up of 4 polypeptide chain.
Each chain has a haem group containing am iron ion which gives its red colour.

Question 5

What does each molecule of human haemoglobin contain?

Answer 5

4 oxygen molecule.

Question 6

What happens in the lungs?

Answer 6

Oxygen joins to haemoglobin in the red blood cells to form oxyhaemoglobin.
This is a reversible reaction.
Near body cells oxygen leaves haemoglobin and it turns back to haemoglobin.

Question 7

What is it called when oxygen molecule joins to haemoglobin?

Answer 7

Association.

Loading.

Question 8

What is it called when an oxygen molecule leaves oxyhaemoglobin?

Answer 8

Dissociation.

Unloading.

Question 9

What does Affinity for oxygen mean?

Answer 9

The tendency for a molecule to bind with oxygen.

Question 10

Name one of the conditions which affects haemoglobins affinity for oxygen?

Answer 10

Is the partial pressure of oxygen.

pO2.

Question 11

What is pO2?

Answer 11

A measure of oxygen concentration.

Question 12

The greater the concentration of dissolved oxygen in cells the…

Answer 12

Higher the partial pressure of oxygen.

Question 13

A higher concentration of oxygen…

Answer 13

The higher haemoglobins affinity for oxygen is.

Question 14

What is the concentration of oxygen like when oxygen loads onto haemoglobin for for oxyhaemoglobin?

Answer 14

High concentration of oxygen.

Question 15

Where is there a low concentration of oxygen?

Answer 15

When oxyhaemoglobin unloads is oxygen.

Question 16

Explain how oxygen loads and unloads in the body?

Answer 16

Oxygen enters blood capillaries at alveoli in the lungs.
Alveoli have high concentration of oxygen, so oxygen loads onto haemoglobin to form oxyhaemoglobin.
When cells respire they use up oxygen lowering the concentration of oxygen.
Red blood cells deliver oxyhaemoglobin to respiring tissues, where it unloads its oxygen.
Haemoglobin returns to lungs to pick up more oxygen.

Question 17

SUMMARISE.

What happens in the alveoli in the lungs?

Answer 17

High oxygen concentration.
High po2.
High affinity.
Oxygen loads.

Question 18

SUMMARISE.

What happens in the respiring tissue?

Answer 18

Low oxygen concentration.
Low Po2.
Low affinity.
Oxygen unloads.

Question 19

What does an OXYGEN dissociation curve show?

Answer 19

How saturates the haemoglobin is with oxygen at any given partial pressure.

Question 20

At the top part of the S-shaped graph where the oxygen concentration is high, what happens?

Answer 20

Haemoglobin has a high affinity for oxygen, so has a high saturation of oxygen.

Question 21

At the bottom of the S-shaped graph where the oxygen concentration is low, what happens?

Answer 21

Haemoglobin has a low affinity for oxygen, so has a low saturation of oxygen.

Question 22

What does 100% saturation mean?

Answer 22

Every haemoglobin molecule is carrying the maximum of 4 molecule of oxygen.

Question 23

What does 0% saturation mean?

Answer 23

None of the haemoglobin molecules are carrying any oxygen molecules.

Question 24

Why is the graph S -shaped?

Answer 24

When haemoglobin combines with its first oxygen molecule its shape alters in way which makes it easier for other oxygen molecules to join too.
Haemoglobin begins to get saturated, making it harder ti oxygen molecules to join.

Question 25

What does the steep bit in the middle of the S-shaped graph represent?

Answer 25

When its really easy for oxygen molecules to bind.
Also causes a small change in oxygen concentration which causes a big change in the amount of oxygen carried by the haemoglobin.