16 Ass 8 pt 2 Transport and Gas Exchange in Mammals

Question 1

Q21 a name X and Y

Answer 1

X: mucous gland
Y:Cartilage

Question 2

State the name of the type of biological molecule of which collagen is an example

Answer 2

protein

Question 3

Name the structures of the gas exchange system that contain smooth muscle (check notes bc there might be more than in memo) 3

Answer 3

bronchiole, bronchus & trachea

Question 4

Name the structures of the gas exchange system that DONT contain smooth muscle (check notes bc there might be more than in memo) 1

Answer 4

alveolus

Question 5

List all of the structures through which a blood clot in the left atrium must travel to reach the
blood vessels supplying the brain.
The structures must be listed in the correct sequence. 5

Answer 5

left atrium, atrioventricular valve, left ventricle, semi-lunar valve, aorta

Question 6

Explain why blocking a small artery in the brain leads to brain damage.

Answer 6

Restricts oxygen flow to the brain cells

Question 7

What does AF stand for?

Answer 7

Atrial fibrillation

Question 8

What does myogenic mean in the heart

Answer 8

The electrical activity controlling the rhythm of a regular heartbeat begins in the heart muscle itself

Question 9

What is Atrial fibrillation? 3

Answer 9

An abnormal heart rhythm

that causes rapid, irregular contractions of the atria.

If untreated can cause a stroke

Question 10

What is a common cause of AF?

Answer 10

When a small group of muscle cells in the left atrium wall starts to send electrical impulses to the surrounding heart muscle cells

Question 11

Explain how the control of the heartbeat by the sinoatrial node can be disrupted by AF, resulting in
rapid and irregular atrial contractions 3

Answer 11

The sinoatrial node won’t be able to work as a pacemaker

because the impulses from other muscles will interfere

the extra impulses will cause extra contractions in the atria

Question 12

Q22 c identify enzyme X

Answer 12

carbonic anhydrase

Question 13

Q22 c identify molecule Y

Answer 13

haemoglobonic acid

Question 14

What does carbonic anhydrase do?

Answer 14

It catalyses the reaction between CO2 and water to form carbonic acid

Question 15

What does haemoglobonic acid do?

Answer 15

It causes oxygen to be released from haemoglobin

Question 16

Q22 c Identify the aqueous environment labelled Z

Answer 16

Tissue fluid

Question 17

List the stages of oxygen dissociation 6

Answer 17

CO2 diffuses from blood plasma into the red blood cells

Carbonic anhydrase catalyses the reaction btw CO2 & water to form carbonic acid

carbonic acid dissociates to form hydrogen ions & hydrogencarbonate ions

Oxygen is released from haemoglobin

hydrogencarbonate ions diffuse out of the red blood cell into the plasma

chloride ions diffuse into the red blood cell

Question 18

Name specialised cells in the gas exchange system that prevent harmful microscopic particles
from reaching the alveoli. 3

Answer 18

Goblet cells, cilliated epithelial cells, macrophages

Question 19

What do Goblet cells do to prevent harmful microscopic particles from reaching the alveoli?

Answer 19

They secrete mucus

which traps dirt and pathogens

Also moistens the air

Question 20

What do cilliated epithelial cells do to prevent harmful microscopic particles from reaching the alveoli? 2

Answer 20

Move mucus away from the lungs

& back to the larynx so it can be swallowed

Question 21

What do macrophages do to prevent harmful microscopic particles from reaching the alveoli? 2

Answer 21

They are clustered on surface of tracheal & bronchial lining

React to and destroy pathogens

Question 22

Explain why red blood cells and albumin do not leave the capillary

Answer 22

They’re too large to fit through endothelial pores

Question 23

Name the chemical reagent or reagents used to test for proteins in a sample of blood plasma
and state the colour change that will be seen if the protein is present. 2

Answer 23

Biuret reagent

it changes from blue to purple

Question 24

What is oedema? 2

Answer 24

a swelling of tissues

caused by the accumulation of tissue fluid surrounding the body
cells in the capillary network

Question 25

Suggest and explain how a low blood albumin concentration can lead to oedema.3

Answer 25

Blood will have a higher water potential with less albumin

so the water potential gradient will be less steep at the venous end so less water returns to the capillary

and more tissue fluid will leave the capillary down the water potential gradient

Question 26

Name the type of membrane protein to which the cell signalling molecules bind

Answer 26

receptor protein

Question 27

Name the blood vessels entering the heart that bring blood from the rest of the body.

Answer 27

Vena Cava

Question 28

Outline and explain the events that occur in the heart during ventricular diastole 4

Answer 28

The ventricles relax, causing the pressure to drop be low the arteries

this causes semilunar valves to snap shut

all heart muscles now relax and blood flows from veins to the atria

while some trickles through atrial ventricular valves into the ventricles

Question 29

Q24 c) State the base sequences of DNA triplet P G and R

Answer 29

CTC
GTG
GUG

Question 30

Name the type of polypeptide in a haemoglobin molecule that is different in sickle cell
haemoglobin compared to normal haemoglobin.

Answer 30

Beta-globin