Gas Exchange

Question 1

Gas exchange in insects

Answer 1

-Protective exoskeleton made of chitin so gases cannot easily pass through

-Small openings called spiracles allow gas in

-Leads to tracheae and then tracheoles
-Each tracheole is a single cell so rapidly diffuses

Question 2

Affinity to Haemoglobin

Answer 2

High oxygen conc = high affinity
Low oxygen conc = low affinity

gas exchange surfaces (high affinity so oxygen attached)
respiring tissue (low affinity so oxygen released)

Question 3

Oxygen association curve

Answer 3

At low partial pressures of oxygen, haemoglobin has a low affinity for oxygen

Bohr Effect
-Increase in CO2 concentration shifts curve to right
causes oxygen affinity to decrease)
-Shifting curve (left = higher affinity, right = lower affinity)

Question 4

inhalation

Answer 4

The external intercostal muscles contract
Diaphragm contracts and flattens.
This causes the ribs to move up and out.
The volume inside the chest increases so the pressure decreases.

Question 5

exhalation

Answer 5

The internal intercostal muscles contract and the diaphragm relaxes and moves up.
The ribs move in & down
This causes the volume inside the chest to decrease and the pressure increase

Question 6

Specific blood vessels

Answer 6

Hepatic artery and vein (liver)
Renal artery and vein (kidney)

Question 7

structure of haemoglobin

Answer 7

Quaternary structure

Each polypeptide chain associated with haemo group