Section 3: Chapter 7: Mass transport NEED TO DO PLANTS

Question 1

How many oxygen molecules can bind to haemoglobin?

Answer 1

4.

Question 2

What is haemoglobin made up of?

Answer 2

2 beta polypeptide chains, 2 alpha polypeptide chains and 4 haem groups.
(good picture pg161 of textbook)

Question 3

As partial pressure of oxygen increases, haemoglobin’s affinity for oxygen ______.

Answer 3

Increases.

Question 4

What happens to the oxygen attached to haemoglobin if the partial pressure of oxygen decreases?

Answer 4

Oxygen is unloaded/disassociated.

Question 5

What are the x and y axis on an oxygen dissociation curve?

Answer 5

x - Partial pressure of oxygen.

y - Saturation of haemoglobin with oxygen.

Question 6

Briefly explain the oxygen disassociation curve.

Answer 6

1) Initally shallow as hard for 1st oxygen to bind.
2) Changes shape after 1st oxygen so 2nd and 3rd bind easier - positive cooperativity.
3) Graph flattens - chance 4th oxygen will bind is low.

Question 7

What is positive cooperativity? (think haemoglobin)

Answer 7

The 1st oxygen binding to haemoglobin makes it easier for the 2nd and 3rd to bind as Hb’s shape changes.

Question 8

How is fetal haemoglobin different from adults?

Answer 8

Higher affinity for oxygen as oxygen saturation of blood has decreased by the time it reaches placenta.

Question 9

What is the Bohr effect?

Answer 9

The greater the concentration of CO2 the more readily haemoglobin releases oxygen.

Question 10

In the presence of carbon dioxide, the affinity of haemoglobin for oxygen ________.

Answer 10

Decreases.

Question 11

What does CO2 do to make haemoglobin have a lower affinity of oxygen?

Answer 11

Created slightly acidic conditions, so Hb changes shape and unloads oxygen easier.

Question 12

What are some common features of circulatory systems? (3 points)

Answer 12

1) Suitable medium - For substances to dissolve in. eg/ blood.
2) Means of moving medium - a pump. eg/ heart.
3) Means of controlling flow. eg/ valves.

Question 13

Why is a mammals circulatory system described as a closed double circulatory system?

Answer 13

• Blood is confined to vessels.

- Blood is passed through he heart twice.

Question 14

Which chamber has thicker, more muscular walls, atrium or ventricle?

Answer 14

Ventricle.

Question 15

What are the 4 main vessels connected to the heart?

Answer 15

Aorta, pulmonary artery, pulmonary vein, vena cava.

Question 16

What is the aorta connected to and what does it carry?

Answer 16

• Left ventricle.

- oxygenated blood → body.

Question 17

What is the pulmonary artery connected to and what does it carry?

Answer 17

• Right ventricle.

- Deoxygenated blood → lungs.

Question 18

What is the pulmonary vein connected to and what does it carry?

Answer 18

• Left atrium.

- Oxygenated blood from the lungs.

Question 19

What is the vena cava connected to and what does it carry?

Answer 19

• Right ventricle.

- Deoxygenated blood from the body.

Question 20

What are the 3 stages of the cardiac cycle?

Answer 20

1) Cardiac diastole.
2) Atrial systole.
3) Ventricular systole.

Question 21

What happens during cardiac diastole? (5 points)

Answer 21

1) Atria and ventricles relax.
2) Heart elastic recoils - lowers pressure.
3) Blood - Pulmonary vein and vena cava → atria.
4) Atrioventricular valves open - blood flows - atrium → ventricles.
5) Semi lunar valves closed.

Question 22

What happens during atrial systole? (1 point)

Answer 22

Atria contract so all blood goes to ventricles.

Question 23

What happens during ventricular systole?

Answer 23

1) Ventricles contract - atrioventricular valves close.
2) Semi-lunar valves open.
3) Blood leaves ventricles through aorta and pulmonary artery.

Question 24

What is the structure of the arteries related to function?

Answer 24

• Thick walls - bc of high blood pressure.
• Elastic tissue - stretch and recoil for smooth blood flow.
• Smooth muscle lined with smooth epithelium - reduce friction, smooth blood flow.

Question 25

What is the structure and function of arterioles?

Answer 25

• branch off arteries.
• Thin and less muscular walls.
• Feeds blood to capillaries.

Question 26

What is the structure of capillaries related to function?

Answer 26

• Small and one cell thick - quick exchange.

Question 27

What is the structure of veins related to function?

Answer 27

• Wide lumen - maximum amount of volume.
• Thin walled - low pressure, no chance of bursting.
• Valves to prevent back-flow.
• Little elastic or muscle tissue as low pressure.
• Carries blood from body → heart.

Question 28

Where are the atrioventricular valves?

Answer 28

Between the atrium and ventricles.

Question 29

Where are the semi-lunar valves?

Answer 29

Pulmonary artery and aorta (vessels that transport blood out of the ventricles).

Question 30

What is the purpose of tissue fluid?

Answer 30

Supplies issues with essential solutes in exchange for waste products.

Question 31

Describe tissue fluid formation.

Answer 31

• Hydrostatic pressure is created in the capillaries by blood pumping.
• Pressure causes tissue fluid to leave blood plasma.
• Ultrafiltration - only small mols leave capillary because only small pressure.

Question 32

Describe tissue fluid return.

Answer 32

• Loss of tissue fluid in capillaries → low hydrostatic pressure.
• Blood at capillary end of lower hydrostatic pressure than tissue fluid.
• Tissue fluid forced back in.
• Blood plasma now has low Ψ, water leaves tissue → blood.
• Remaining tissue fluid → lymphatic system