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)
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1
Q

What type of molecule is haemoglobin?

A

Conjugated protein with a haem group - 4 polypeptide chains

2
Q

Haemoglobin is found where?

A

In RBCs

3
Q

Haemoglobin bings to what?

A

Oxygen

4
Q

What is the role of Haemoglobin?

A

To transport oxygen around the body

5
Q

To be efficient what must Haemoglobin do?

A

Readily associate with oxygen at exchange surfaces

Readily dissociate from oxygen when tissues need it

6
Q

What is it called when oxygen and Haemoglobin bind?

A

Oxyhaemoglobin

7
Q

What are the two types of Haemoglobin?

A

Haemoglobin with high affinity for oxygen

Haemoglobin with low affinity for oxygen

8
Q

Haemoglobin with high affinity for oxygen does what?

A

Takes oxygen up easily

Hard to release

9
Q

Haemoglobin with a low affinity for oxygen does what?

A

Takes it up less easily

Releases it readily

10
Q

What is loading or associating?

A

The process of oxygen combining with Haemoglobin at exchange surfaces

11
Q

What is unloading or dissociating?

A

Oxygen released

12
Q

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

A

Absorb oxygen

13
Q

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

A

Load easily

14
Q

The further to the left the higher the what?

A

Affinity for oxygen

15
Q

Where is myoglobin found?

A

In muscle

16
Q

What does myoglobin have/do?

A

High affinity for oxygen
One haem group
Acts as oxygen reserve

17
Q

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

A

Binds to amine groups forming carbaminohaemoglobin

18
Q

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

A

Hydrogen carbonate by carbonic anhydrase

19
Q

H2CO3 dissociates into what?

A

H+

HCO3-

20
Q

The HCO3- moves out of RBCs to where?

A

Plasma

21
Q

Negatively charged chloride ions move into where?

A

RBCs

22
Q

Why does foetal Haemoglobin have a higher affinity for oxygen?

A

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

23
Q

CO2 lowers Haemoglobins what?

A

Affinity for oxygen

24
Q

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

A

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

25
Q

The Bohr effect is important to provide what?

A

Necessary for providing oxygen to active tissues readily

Oxygen binding easily in lungs

26
Q

At gas exchange surfaces what is removed?

A

CO2

27
Q

Low levels of CO2 increases what?

A

PH

28
Q

High pH changes what?

A

Haemoglobin so oxygen loads readily - increased affinity

29
Q

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

A

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

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