2. Haemoglobin Flashcards Preview

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Flashcards in 2. Haemoglobin Deck (25)
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1
Q

What is the role of haemoglobin?

A

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

2
Q

Give examples of where haemoglobin?

A

Earthworms.
Starfish.
Some insects/plants/bacteria.

3
Q

Give examples of a mass transport system?

A

Circulatory system.

4
Q

What is haemoglobin made up of?

A

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.

5
Q

What does each molecule of human haemoglobin contain?

A

4 oxygen molecule.

6
Q

What happens in the lungs?

A

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.

7
Q

What is it called when oxygen molecule joins to haemoglobin?

A

Association.

Loading.

8
Q

What is it called when an oxygen molecule leaves oxyhaemoglobin?

A

Dissociation.

Unloading.

9
Q

What does Affinity for oxygen mean?

A

The tendency for a molecule to bind with oxygen.

10
Q

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

A

Is the partial pressure of oxygen.

pO2.

11
Q

What is pO2?

A

A measure of oxygen concentration.

12
Q

The greater the concentration of dissolved oxygen in cells the…

A

Higher the partial pressure of oxygen.

13
Q

A higher concentration of oxygen…

A

The higher haemoglobins affinity for oxygen is.

14
Q

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

A

High concentration of oxygen.

15
Q

Where is there a low concentration of oxygen?

A

When oxyhaemoglobin unloads is oxygen.

16
Q

Explain how oxygen loads and unloads in the body?

A

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.

17
Q

SUMMARISE.

What happens in the alveoli in the lungs?

A

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

18
Q

SUMMARISE.

What happens in the respiring tissue?

A

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

19
Q

What does an OXYGEN dissociation curve show?

A

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

20
Q

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

A

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

21
Q

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

A

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

22
Q

What does 100% saturation mean?

A

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

23
Q

What does 0% saturation mean?

A

None of the haemoglobin molecules are carrying any oxygen molecules.

24
Q

Why is the graph S -shaped?

A

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.

25
Q

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

A

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.