3.2 Transport In Animals (blood)

Question 1

What is the composition of blood?

Answer 1

• Red blood cells- Transport O2
• White blood cells- Immunity
• Platelets- Clotting
• Plasma- transport of Glucose,amino acids,mineral ions and hormones (mostly consists of water)

Question 2

What is the role of the blood?

Answer 2

To transport:
- gasses
- digested food
- nitrogenous waste (urea)
- platelets to site of injury
- antibodies

Question 3

What is tissue fluid?

Answer 3

Fluid similar in composition to blood which transports substances from blood to cells and vice versa

Question 4

How does tissue fluid differ to blood?

Answer 4

Has no cells/large plasma proteins

Question 5

What is hydrostatic pressure?

Answer 5

Pressure exerted by a liquid on the walls of its container

Question 6

What is oncotic pressure?

Answer 6

Tendency of water to move into the blood (via osmosis) as a result of plasma proteins

Question 7

Which end of a capillary has a higher hydrostatic pressure?

Answer 7

The arteriole end

Question 8

What end of the capillary has the highest oncotic pressure?

Answer 8

The venule end

Question 9

How do substances exit the capillary?

Answer 9

The capillary endothelial wall has fenestrations in it

Question 10

At what end of the capillary does fluid exit the capillary?

Answer 10

The arteriole end

Question 11

What happens at the venule end of the capillary?

Answer 11

Water potential in blood is more negative due to less water so the oncotic pressure becomes higher in relation to hydrostatic pressure and some fluid reenters.

Question 12

What is Lymph?

Answer 12

Fluid with the same composition of plasma/tissue fluid travelling in lymph vessels

Question 13

What are the features of Lymph?

Answer 13

Less oxygen and nutrients than blood or tissue fluid
More waste products
Contains fatty acids

Question 14

What are lymph nodes?

Answer 14

Lymphocytes that have collected together
Produce antibodies/intercept pathogens

Question 15

How does tissue fluid enter lymph vessels?

Answer 15

Through the open ended ends

Question 16

What adaptations do erythrocytes have?

Answer 16

• bi-concave shape provides a larger surface area
• no nucleus means more room for haemoglobin

Question 17

What is the composition of haemoglobin?

Answer 17

4 polypeptides with 4 Fe + ions which O2 bind to

Question 18

How is oxygen obtained at the lungs?

Answer 18

There is a high PP of O2 (high concentration)
Haemoglobin has a high affinity for oxygen
Haemoglobin is saturated by oxygen as lots of Haemoglobin bind to Fe ions

Question 19

How is oxygen delivered to body tissues?

Answer 19

• Low pp of O2
• Haemoglobin has a low affinity for oxygen
• Oxygen dissociates from Haemoglobin causing oxygen to be released
• Haemoglobin has a low saturation of oxygen

Question 20

What is the name of the curve formed by oxygen dissociation?

Answer 20

Sigmoid curve

Question 21

What causes the sigmoid curve?

Answer 21

• Conformational change so ppO2 bring higher increases the affinity for oxygen
• This is called co-operative binding and unloading
• the second and third O2 molecule are easier to bind/unload

Question 22

How does ppO2 effect O2 saturation?

Answer 22

Small increase of ppO2 = Large increase of O2 saturation
Small decrease of ppO2 = Large decrease of O2 saturation

Question 23

How is foetal haemoglobin different?

Answer 23

Has a higher affinity for oxygen- Two polypeptide chains are different
Means that no matter ppO2 oxygen will be transferred

Question 24

What happens to the sigmoid curve of a foetus?

Answer 24

Curve shifted to the left

Question 25

What are the three ways CO2 are transported?

Answer 25

1. 5% directly into plasma
2. 10% bound to haemoglobin
3. 85% in the form of hydrogen carbonate atoms

Question 26

What is the function of carbonic anhydrase in the transport of CO2?

Answer 26

An enzyme which reacts the CO2 with water to form carbonic acid

Question 27

What happens to the carbonic acid in transport of CO2?

Answer 27

It dissociates to form H+ and HCO3-

Question 28

What do the H + ions in transport of CO2 combine with?

Answer 28

Haemoglobin to form haemoglobonic acid

Question 29

How is Hydrogen carbonate removed from the blood cells?

Answer 29

Chloride ions are exchanged and while chloride ions go in the hydrogen carbonate comes out

Question 30

What is the Bohr effect?

Answer 30

H + ions compete for space on haemoglobin molecules
H + ions displace the oxygen from haemoglobin
More oxygen is released to respiring tissues

Question 31

What happens to the dissociation curve in reference to the Bohr effect?

Answer 31

Shifted down to the right