3.2 Haemoglobin & CO2 transport Flashcards Preview

A Level Biology > 3.2 Haemoglobin & CO2 transport > Flashcards

Flashcards in 3.2 Haemoglobin & CO2 transport Deck (29):
1

What type of molecule is haemoglobin?

Conjugated protein with a haem group - 4 polypeptide chains

2

Haemoglobin is found where?

In RBCs

3

Haemoglobin bings to what?

Oxygen

4

What is the role of Haemoglobin?

To transport oxygen around the body

5

To be efficient what must Haemoglobin do?

Readily associate with oxygen at exchange surfaces
Readily dissociate from oxygen when tissues need it

6

What is it called when oxygen and Haemoglobin bind?

Oxyhaemoglobin

7

What are the two types of Haemoglobin?

Haemoglobin with high affinity for oxygen
Haemoglobin with low affinity for oxygen

8

Haemoglobin with high affinity for oxygen does what?

Takes oxygen up easily
Hard to release

9

Haemoglobin with a low affinity for oxygen does what?

Takes it up less easily
Releases it readily

10

What is loading or associating?

The process of oxygen combining with Haemoglobin at exchange surfaces

11

What is unloading or dissociating?

Oxygen released

12

At low concentrations of oxygen what is it difficult to do?

Absorb oxygen

13

Once the first oxygen is loaded what do the remaining 3 molecules do?

Load easily

14

The further to the left the higher the what?

Affinity for oxygen

15

Where is myoglobin found?

In muscle

16

What does myoglobin have/do?

High affinity for oxygen
One haem group
Acts as oxygen reserve

17

When carbon dioxide diffuses into bloodstream what does 10-20% do?

Binds to amine groups forming carbaminohaemoglobin

18

75-85% of carbon dioxide is converted into what?

Hydrogen carbonate by carbonic anhydrase

19

H2CO3 dissociates into what?

H+
HCO3-

20

The HCO3- moves out of RBCs to where?

Plasma

21

Negatively charged chloride ions move into where?

RBCs

22

Why does foetal Haemoglobin have a higher affinity for oxygen?

To maximise oxygen uptake from the mothers bloodstream which has already used some up by the time it reaches the placenta

23

CO2 lowers Haemoglobins what?

Affinity for oxygen

24

Dissolved CO2 has what effect on pH and what does this do? What is this called?

Lowers PH because it is acidic
Causes proteins to change shape releasing CO2
BOHR EFFECT

25

The Bohr effect is important to provide what?

Necessary for providing oxygen to active tissues readily
Oxygen binding easily in lungs

26

At gas exchange surfaces what is removed?

CO2

27

Low levels of CO2 increases what?

PH

28

High pH changes what?

Haemoglobin so oxygen loads readily - increased affinity

29

In tissues where CO2 is made, pH decreases so what happens?

Haemoglobin changes shape
Lowers affinity for O2
So it is unloaded into respiring tissues

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