Mass Transport in Animals

Question 1

What is the definition of digestion?

Answer 1

Large biological molecules are hydrolysed by enzymes into smaller molecules that can be absorbed across cell membrane

Question 2

How are carbohydrates digested?

Answer 2

1. Starch is Hydrolysed by Amylase to Maltose
2. Maltase is then hydrolysed by Maltase into 2 Glucose molecules
3. These are then absorbed by co-transport with Na+

Question 3

How are lipids digested?

Answer 3

1. Lipid droplet is emulsified into small lipid droplets
2. These small lipid droplets are hydrolysed by lipase into micelles
3. These are then absorbed into the ileum

Question 4

What is a micelle?

Answer 4

1. Tiny droplets of monoglyceride + fatty acids that release monoglycerides close to the surface of cells -> diffuse in to epithelium of small intestine

Question 5

What does endopeptidase do ?

Answer 5

Hydrolyses peptide bonds WITHIN a polypeptide

Question 6

What does exopeptidase do?

Answer 6

Hydrolyses the peptide bonds at the ends of the polypeptides

Question 7

What is membrane bound dipeptidase?

Answer 7

Enzymes attached to membranes (eg ileum) hydrolyse the peptide bonds between dipeptides

Question 8

What is haemaglobin?

Answer 8

1. A protein with a quaternary structure
2. Found in red blood cells
3. Transports oxygen

Question 9

What is the Bohr effecct?

Answer 9

1. When an organism respires a lot there is a higher concentration of Co2 in the blood
2. The higher the CO2 level the more carbonic acid present
3. The more acidic the blood the less is Hb’s affinity for O2
4. Oxygen ,therefore, more easily unloads at respiring cells

Question 10

Describe the structure on an artery.

Answer 10

1. Narrower lumen than vein
2. Folded endothelium
3. Thick layer of muscle
4. Elastic tissue

Question 11

What is a benefit of Elastic tissue being able to stretch and recoil?

Answer 11

1. It stretches when under high pressure to prevent any damage
2. When the ventricles relax it recoils to maintain a smooth pressure

Question 12

Describe the structure of a vein.

Answer 12

1. Thin muscle
2. Wide lumen
3. One way valves
4. Low pressure

Question 13

Describe the structure of capillaries.

Answer 13

1. 1 cell thick
2. Lowest pressure

Question 14

What does the pulmonary artery do?

Answer 14

Transports deoxygenated blood to the lungs

Question 15

What does the atria do?

Answer 15

Pump blood to the ventricles

Question 16

What does the Vena Cava do?

Answer 16

Returns blood to the heart from the body

Question 17

What does the Pulmonary vein do?

Answer 17

Returns oxygenated blood from lungs to the heart

Question 18

What does the aorta do?

Answer 18

Transports oxygenated blood to the body

Question 19

What are the atrioventricular valves?

Answer 19

1. Uni directional valves
2. Open when pressure is higher in the atria than in the ventricles

Question 20

What are the semi-lunar valves?

Answer 20

Open when pressure is higher in ventricles than in blood vessels

Question 21

What is atheroma?

Answer 21

The build up of fatty plaque in arteries

Question 22

What is Thrombosis?

Answer 22

Blood clot in arteries

Question 23

What is an aneurysm?

Answer 23

When stretching endothelium baloons out through muscle of an artery

Question 24

What is a myocardial infarction?

Answer 24

A heart attack

Question 25

How might coronary arteries being blocked by fat deposits affect a person?

Answer 25

1. Could cause a heart attack
2. Greatly reduces the flow of O2 and glucose to the heart muscle
3. Cant respire

Question 26

Describe how tissue fluid is formed and then returned.

Answer 26

1. Hydrostatic pressure is higher in blood than in tissue fluid
2. Water and small molecules are forced out
3. Large molecules stay inside the capillary ( proteins)
4. Pressure decreases as you move along the capillary
5. Water potential becomes lower than water potential in tissues as the proteins remain in the blood
6. Water moves into the capillary by osmosis, any excess drains into the lymphatic system