Respiration

Question 1

What are the names of the 2 processes involved in respiration?

Answer 1

glycolysis followed by the Kreb’s cycle

Question 2

What is Fick’s law?

Answer 2

the rate of diffusion depends on the cross-section area, the concentration of solute and the diffusion constant (Krogh’s diffusional constant used instead of Fick’s diffusional constant because it’s easier to measure in biological systems)

Question 3

What is Kleiber’s law?

Answer 3

the total metabolism is roughly proportional to body mass (rate = (body mass)^0.75)

Question 4

Describe the changes in metabolic rate of a poikilotherm with a temperature change of 5 to 35 degrees C

Answer 4

metabolic rate increases by 28x, but oxygen solubility is halved so ventilation needs to increase by 56x

Question 5

What is the % utilisation of oxygen from a medium in humans?

Answer 5

20-25%

Question 6

What is the % utilisation of oxygen from a medium in fish?

Answer 6

around 80% (due to continuous countercurrent ventilation)

Question 7

How much more heat is lost in aquatic animals and why?

Answer 7

90,000x - heat capacity of water is 3,000x that of air, and 30x less oxygen is present in water

Question 8

Why are there no gill-breathing homeotherms?

Answer 8

too much oxygen would be required to provide for heat-regulating mechanisms, and blood cannot be restricted to the gills to minimise heat loss

Question 9

Name 3 types of organisms which have an open circulatory system?

Answer 9

insects, crustacea and molluscs (higher molluscs have brachial heart for increased metabolic needs)

Question 10

What type of circulatory system do oligochaete annelids have?

Answer 10

closed circulatory system - major blood vessels with endothelial lining and auxiliary heart structure.

Question 11

What defines a semi-closed circulatory structure?

Answer 11

the circulatory system works in combination with the water vascular system

Question 12

Name a group of organisms that have a semi-closed circulatory structure

Answer 12

hemichordates

Question 13

What is the Bohr effect?

Answer 13

The production of CO2 in the tissues by aerobic respiration or lactic acid by anaerobic respiration generates an influx of H+ that causes conformational changes in the structure/affinity of haemoglobin.

Question 14

What is the root effect?

Answer 14

a change in the number of units of haemoglobin capable of carrying oxygen, in response to an influx of H+

Question 15

What is the collective outcome of the Bohr and Root effects?

Answer 15

causes the unloading of oxygen from haemoglobin into solution where there is active respiration.

Question 16

What is the chloride/hamburger shift?

Answer 16

The CO2 generated in the tissues diffuses into red blood cells, forming H+ and HCO3- ions which are exchanged for Cl-, further reducing the affinity of haemoglobin for oxygen.

Question 17

What is the Haldane Effect?

Answer 17

the opposite of the chloride/hamburger shift occurring in the gills, where haemoglobin affinity for oxygen is restored.