Chapter 7- Mass Transport

Question 1

What are the components of blood?

Answer 1

Plasma
Red blood cells
Platelets
White blood cells

Question 2

What are the % of plasma in the blood, cells in the blood?

Answer 2

Plasma= 55%

Cells in suspension= 45%

Question 3

What is plasma made from?

Answer 3

90% water
10% dissolved substances- including:
•plasma proteins
• nutrients
• wastes e.g urea
• mineral salts
• hormones 
• gases

Question 4

What is tissue fluid?

Answer 4

The watery liquid surrounding cells (their immediate environment, it bathed the body cells)

Question 5

How do substances leave the capillaries into the tissue fluid?

Answer 5

Through the fenestra/ capillary pores

Question 6

What does the lymphatic system do

Answer 6

• Helps to get rid of harmful body toxins, waste and other unwanted material produced by cells
• transport white blood cells throughout the body to fight infections

Question 7

Whats the role of the heart in tissue fluid formation

Answer 7

• contraction of the ventricles crests high blood/ hydrostatic pressure.
• this forces water and dissolved substances out of the capillaries forming tissue fluid

Question 8

What are the risk factors associated with cardiovascular disease?

Answer 8

Smoking
Diabetes
Physical activity
Obesity 
High cholesterol 
High BP
Genetics
Gender
Age
Ethnicity

Question 9

What is cholesterol?

Answer 9

It’s a waxy lipid found in the cell membrane and is produced in the liver and travels through ur blood stream

Question 10

What does LDL stand for?

Is it the good or bad cholesterol? Why?

Answer 10

Low density lipoprotein
Bad- because it can build up in your arteries which cause them to narrow and may cause blockages.
This can lead to strokes and heart attacks

Question 11

What does HDL stand for?

Is it’s the good or bad cholesterol? Why?

Answer 11

• High density lipoprotein

* Good- as it transports the LDL away from the arteries and prevents blockages back to the liver

Question 12

What is the Bohr effect?

Answer 12

When Co2 lowers the blood pH ( by forming carbonic acid) which causes haemoglobin to realease O2

Question 13

What are 3 factors that cause the Bohr effect?

Answer 13

• High Co2 concentration
• Low blood pH
• High temperature

Question 14

Describe and explain two ways in which red blood cells are adapted to oxygen transport (4marks)

Answer 14

1. biconcave shape- provides a high SA:V ratio
   - meaning there’s a short diffusion pathway for O2
2. Red blood cells lack a nucleus
   - more space for haemoglobin

Question 15

Mammals that live at different altitudes often have different haemoglobin. Suggest how a mammals haemoglobin might be adapted to live at high altitude. (1mark)

Answer 15

•They have a HIGHER (don’t allow just high) affinity to oxygen

Question 16

Haemoglobin can change shape. Explain how a change in shape causes the oxyhemoglobin dissociation graph to be an S shape. (2marks)

Answer 16

• !!COOPERATIVE BINDING
• After the first oxygen molecule binds it causes a shape change.
• Means O2 can binds more easily
• 4th O2 is harder to bind as there is only one space left.

Question 17

With reference to the different partial pressure of O2 (ppO2) throughout the body explain how haemoglobin supplies O2 to different areas of the human body. ( 3marks)

Answer 17

• Haemoglobin is loaded with O2 in an area of higher ppO2.
• There’s higher ppO2 in lungs where gaseous exchange takes place.
• O2 in unloaded in a place of lower ppO2.
• There’s lower ppO2 in capillaries and tissues.

Question 18

Describe the structure of a haemoglobin

Answer 18

It has a Quaternary structure, made of 4 polypeptide chains. Each with a hawk group which contains a Fe2+

Question 19

When can it be said that a haemoglobin is saturated?

Answer 19

When all 4 O2 molecules have bonded to the 4 iron ions (haem group) and no more O2 can be loaded

Question 20

What is the Bohr effect?

Answer 20

• Oxyhemoglobin dissociation graph shift to the right
• when CO2 from respiring tissues bings to the oxyhemoglobin make the affinity to O2 lower.
• Releases O2 easier into the respiring tissues