Unit 3 part 2

Question 1

What is ventilation

Answer 1

Refers to the method by which air (or water in fish ) is passed over the respiratory surface to ensure a high concentration gradient is maintained

Question 2

What occurs during inspiration

Answer 2

External intercostal muscles contracts
Internal intercostal muscles relax
Diaphragm contracts
These increases volume of thoracic cavity
Pressure decreases below atmospheric

Question 3

What occurs during expiration

Answer 3

Opposite of inspiration

Question 4

What is cooperative binding

Answer 4

A molecule of oxygen binds to one of the haem units this causes a slight change in the tertiary structure of other haem units so increases their affinity for oxygen allowing the second molecule to bind more easily, and the third and fourth even more easily

Question 5

What is haemoglobin

Answer 5

An iron containing pigment, which loosely and reversible combines with oxygen to form oxyhemoglobin

Question 6

What is the Bohr effect

Answer 6

Decrease in pH of blood plasma due to CO2 dissolving

Question 7

How does pH affect haemoglobin

Answer 7

Change in pH changes the quaternary structure of haemoglobin and lowers the affinity of haemoglobin to oxygen
Oxygen dissociation curve moves to the right
Haemoglobin releases more oxygen