Health And Risk

Question 1

Why is water a good solvent?

Answer 1

• it’s polar, ions can easily dissolve in it.

- most biological reactions take place in solution

Question 2

What is cohesion?

Answer 2

Attraction between two molecules of the same type

Question 3

What is adhesion?

Answer 3

Attraction between two molecules of different types.

Question 4

What is a mass transport system used for?

Answer 4

Used to carry raw materials from specialised exchange organs to body cells, and remove metabolic waste.

Question 5

Why do multicellular organisms need a mass transport system?

Answer 5

Diffusion across the outer membrane doesn’t yield a fast enough rate of diffusion to meet the metabolic demands of the organism.

Question 6

Which side of the heart pumps deoxygenated blood?

Answer 6

The right side pumps deoxygenated blood to the lungs.

Question 7

Why is the left ventricle thicker than the right?

Answer 7

It needs to produce enough pressure on contraction to pump blood all around the body.

Question 8

What do the atrioventricular and semilunar valves do?

Answer 8

Atrioventricular valves link the atria to ventricles and prevent back flow.

Semilunar valves link ventricles to the pulmonary artery and aorta and present backflow.

Question 9

What is the difference between veins, arteries and capillaries?

Answer 9

• arteries are thick, muscular and have the most elastic tissue. They have an endothelial lining to smooth blood flow.
• veins are wider, blood flows under low pressure. They have valves to prevent back flow.
• capillaries are the site of metabolic exchange. They are only one cell thick

Question 10

what happens during atrial systole?

Answer 10

• ventricles relaxed, atria contract, AV valves open

- pressure in atria increases, pushing blood into ventricles

Question 11

what happens in ventricular systole?

Answer 11

• atria relax, ventricles contract
• pressure in ventricles increases, causes pressure to become higher in the ventricles, AV valves shut.
• pressure in ventricles higher than aorta and PAs, SL valves open

Question 12

what happens during cardiac diastole?

Answer 12

• ventricles and atria relax
• higher pressure in aorta causes SL valves to close
• blood flows back to heart under low pressure

Question 13

what are the ethical issues surrounding the use of invertebrates in experiments on HR?

Answer 13

• cant give consent
• daphnia have a less developed nervous system than vertebrates
• causes distress/suffering to a living organism

Question 14

how does an atheroma form?

Answer 14

• damage to endothelium = inflammatory response
• white blood cells, connective tissue + lipids accumulate
• fibrous plaque builds up, smaller lumen, higher pressure.

Question 15

what are the series of reactions leading to formation of a thrombus?

Answer 15

• thromboplastin (TP) released
• TP + Ca ions = triggering of conv. prothrombin -> thrombin
• thrombin catalyses fibrinogen -> fibrin
• fibrin mesh traps platelets.

Question 16

how does atheroma lead to the formation of a heart attack?

Answer 16

• atheroma damages endothelium causing a rough surface to form
• causes a blood clot to form at the site
• blood clot can obstruct coronary artery

Question 17

how does smoking increase the risk of developing CVD?

Answer 17

• CO binds to haemoglobin, inhibits it
• nicotine makes platelets sticky
• smoking causes decrease in antioxidants

Question 18

how do antioxidants help reduce the risk of CVD?

Answer 18

they protect the cells from damage, preventing cell damage helps prevent atheroma from forming

Question 19

why might people overestimate a risk?

Answer 19

if they are constantly exposed to information about the risk of developing the disease

Question 20

name 3 different types of antihypertensives

Answer 20

• beta blockers
• vasodilators
• diuretics

Question 21

what are the risks and benefits of antihypertensives?

Answer 21

• helps reduce risk of CVD

- palpitations, abnormal HR, fainting, headaches and drowsiness.

Question 22

what does energy budget refer to?

Answer 22

the amount of energy taken in by an organism and the amount of energy used up

Question 23

what is lactose?

Answer 23

beta glucose and galactose with a 1,4-glycosidic bond

Question 24

what is sucrose?

Answer 24

alpha glucose and fructose with a 1,2-glycosidic bond

Question 25

what is maltose?

Answer 25

2x alpha glucose joined with 1,4-glycosidic bonds

Question 26

what is amylopectin?

Answer 26

alpha glucose with 1,4- and 1,6-glycosidic bonds

Question 27

what is glycogen?

Answer 27

• alpha glucose with 1,4- and 1,6- glycosidic bonds
• loads of side branches for rapid hydrolysis
• compact
• insoluble

Question 28

what is starch?

Answer 28

• mixture of amylose and amylopectin with 1,4-glycosidic bonds
• coiled structure, compact, side braches for hydrolysis
• insoluble

Question 29

what is the difference between alpha glucose and beta glucose?

Answer 29

beta glucose has the OH group ‘on top’ whereas alpha glucose has the OH group ‘on the bottom’

Question 30

How are triglycerides synthesised?

Answer 30

with the formation of an ester bond in a condensation reaction between glycerol and 3 fatty acids