Chapter 7

Question 1

What makes up haemoglobin?

Answer 1

4 polypeptide chains and 4 prosthetic haem groups

Question 2

Haemoglobin primary structure

Answer 2

4 polypeptide chains

Question 3

Secondary structure of haemoglobin

Answer 3

Each polypeptide is coiled in a helix

Question 4

Haemoglobin tertiary structure

Answer 4

Each polypeptide is folded into specific shapes

Question 5

Haemoglobin quaternary structure

Answer 5

Four polypeptides are associated with a haem group

Question 6

Affinity definition

Answer 6

Is the ease at which haemoglobin binds to O2

Question 7

The role of haemoglobin (3 things)

Answer 7

To transport O2, to increase the efficiency of O2 transport, haemoglobin must readily associate and dissociate O2

Question 8

On a dissociation curve if the curve is further to left what does this say about the affinity?

Answer 8

Curve further to left, the greater the affinity

Question 9

With oxygen dissociation, the higher the pH the what the affinity

Answer 9

Higher

Question 10

With oxygen dissociation, the higher the [CO2] the what the affinity

Answer 10

Lower

Question 11

Mass transport defintion

Answer 11

Moving substances efficiently over large distances

Question 12

Structure of arteries

Answer 12

Thick elastic walls and smooth muscle, quite a narrow lumen

Question 13

Structure of arterioles

Answer 13

Smaller arteries - thinner elastic walls and less smooth muscle

Question 14

Structure of a vein

Answer 14

Thin walls with a much larger lumen, has valves

Question 15

Mass flow theory

Answer 15

Active transport is used to actively load the solutes into the sieve tubes of the phloem at the source
This lowers the water potential inside the sieve tubes, so water enters the tubes by osmosis from the xylem
This creates a high pressure inside the sieve tubes at the source end of the phloem

At the sink end, solutes are removed from the phloem
This increases the water potential inside the sieve tubes, so water re enters the xylem by osmosis
This lowers the pressure inside the phloem at the sink end

The result is a pressure gradient from the source end to the sink end
This gradient pushes solutes along the phloem to the sink - where they are needed

Question 16

Tissue fluid being formed and reabsorbed

Answer 16

Hydrostatic pressure is higher in the capillary than the outside at the arterial end.
Therefore, the plasma is forced out of the capillary forming tissue fluid.
The plasma takes the smaller molecules but leaves larger molecules like proteins.
This decreases the water potential in the capillary.
Therefore, fluid moves back in at the venous end via osmosis.
Excess fluid is drained back into the bloodstream via the lymph system.