lifestyle health and risk

Question 1

how is loss of heat when sweating related to the dipole nature of water molecules?

Answer 1

• uneven distribution of charge
• forms h bonds w other water molecules
• requires a lot of heat energy to break these bonds

Question 2

how do the properties of water make it an ideal transport medium?

Answer 2

• water is a solvent
• water molecules surround ions
• h bonds form between water mols and solute mols
• water is liquid so has the ability to flow

Question 3

what is a suitable control for the daphnia investigation?

Answer 3

• solution with no caffeine/ distilled water
• to compare with caffeine solutions/ to show that the solvent has no effect on heart rate

Question 4

which drug reduces blood pressure?

Answer 4

antihypertensives

Question 5

which chamber of the heart generates the highest blood pressure?

Answer 5

left ventricle

Question 6

how do pressure differences in the heart ensure efficient pumping of the blood into the arteries?

Answer 6

• pressure increase in the ventricles
• greater pressure in the ventricles than in the atria
• causing av valves to close
• causing the sl valves to open
• forcing blood into the arteries

Question 7

why can high blood pressure increase the risk of developing cardiovascular disease?

Answer 7

• causes damage to the endothelium of the arteries
• inflammatory response/ build up of cholesterol leads to the formation of an atheroma
• plaque develops and narrows the lumen of the artery

Question 8

how could the diet of a person affect the development of CVD?

Answer 8

• high salt intake
• increases blood pressure
• high blood pressure causes damage to endothelium of artery
• high intake of cholesterol/ saturated fat
• high LDLs linked to atheroma formation

Question 9

what is the role of LDLs in the development of atherosclerosis?

Answer 9

• LDLs carry cholesterol in the blood
• cholesterol is deposited to form atheroma
• in the endothelium of the artery

Question 10

how can atherosclerosis result in damage to the heart muscle?

Answer 10

• narrowing of lumen of coronary arteries
• which reduces blood flow/ oxygen to the cardiac muscle
• which reduces aerobic respiration

Question 11

what is the role of thrombin in blood clotting?

Answer 11

*thrombin is an enzyme
* which catalyses the conversion of fibrinogen into fibrin
* a mesh of fibrin traps platelets/ rbc to form a clot

Question 12

what would a diagram of a triglyceride look like if a fatty acid was unsaturated?

Answer 12

• double bond between carbon atoms
• a kink in the fatty acid chain

Question 13

how does glucose move into cells by facilitated diffusion?

Answer 13

• carrier protein in cell surface membrane
• glucose moves from high to low concentration
• glucose binds to carrier protein

Question 14

how does the structure of glycogen allow it to be an energy store?

Answer 14

• polymer of glucose
• to provide glucose for respiration
• branched/ has many terminal ends/ has I,6 glycosidic bonds for rapid hydrolysis
• compact to allow large amount of glucose to be stored in a small space
• insoluble so has no osmotic effect on cells

Question 15

how do the structures of amylopectin and glycogen make them suitable for storing energy?

Answer 15

• branched so can be rapidly hydrolysed
• compact so more energy can be stored
• insoluble so has no osmotic effect
• too large to diffuse across cell surface membrane

Question 16

what reagent can be used to show if vitamin C is present?

Answer 16

DCPIP
goes from blue to colourless

Question 17

what is the function of the SL valve in the aorta?

Answer 17

• opens as blood pumped into aorta
• valve closes during diastole
  *prevents backflow of blood from aorta back into the left ventricle

Question 18

why would platelet inhibitors reduce the risk of a heart attack?

Answer 18

• reduce risk of blood clotting
  *less likely that coronary arteries will be blocked

Question 19

how does the structure of a vein relate to its function?

Answer 19

• large lumen to reduce resistance to blood flow back to the heart
• valves prevent back flow of blood
• thin layer of muscular tissue / elastic tissue to maintain blood pressure
• smooth endothelium to reduce resistance to blood flow

Question 20

explain how a blood clot could form in a blood vessel

Answer 20

artery endo damaged which exposes collagen
releases thromboplastin
catalyses conversion of prothrombin to thrombin
thrombin catalyses conversion of fibrinogen to fibrin
fibrin forms a mesh of fibres that trap rbc and platelets
forming a blood clot

Question 21

explain how atherosclerosis in one part of an artery could increase the likelihood of it developing in another part of the same artery

Answer 21

plaques narrow the lumen
further increasing blood pressure

Question 22

state 2 possible side effects of taking drugs to reduce blood pressure

Answer 22

nausea
muscle cramps
fainting
kidney failure

Question 23

describe how high blood pressure could be reduced by medication and lifestyle changes

Answer 23

treatment w antihypertensive medication
reduce salt intake
stop smoking
increase exercise
reduce weight

Question 24

describe the reaction that joins 2 a-glucose molecules to form a disaccharide

Answer 24

condensation
water is formed

Question 25

give one structural difference between amylose and amylopectin

Answer 25

amylose is unbranched and amylopectin is branched amylose has only 1,4 glycosidic bonds but amylopectin has 1,4 and 1,6

Question 26

State the type of reaction where two monosaccharides join to form a disaccharide molecule.

Answer 26

Condensation

Question 27

Which bonds joins two monosaccharides to form a disaccharide molecule?

Answer 27

Glycosidic

Question 28

Name the two monosaccharides that are produced when sucrose is broken down.

Answer 28

Fructose Glucose

Question 29

Compare and contrast the structure of a disaccharide with glycogen.

Answer 29

Both contain C,H,O Both contain glycosidic bonds Both contain glucose glycogen contains 1,4 and 1, 6-glycosidic bonds whereas disaccharides only contain one type of glycosidic bond glycogen only contains glucose whereas disaccharides can contain glucose and other monosaccharides

Question 30

Describe the structure of an unbranched polysaccharide.

Answer 30

polysaccharide made up of many monosaccharide components joined together by (condensation reactions / glycosidic bonds) (only) 1-4 glycosidic bonds present / no 1-6 glycosidic bonds present

Question 31

Explain why high levels of sugars in a person's diet could lead to obesity.

Answer 31

energy intake higher than energy output (excess) (energy / sugars) can be (stored as / converted to) fat leading to weight gain

Question 32

A student stated that loss of heat when sweating is related to the dipole nature of water molecules. Justify this statement.

Answer 32

Water has an uneven distribution of charge So water forms hydrogen bonds w other water molecules And it requires a lot of heat energy to break these bonds To allow water to evaporate

Question 33

Name the type of reaction in which a molecule of water is involved in the breaking of a bond in another molecule.

Answer 33

Hydrolysis

Question 34

State the type of blood vessel that has no collagen in its wall.

Answer 34

Capillary

Question 35

Explain how blood tests and obesity indicators can be used to collect data to predict the risk of developing CVD.

Answer 35

Blood test to measure cholesterol levels High cholesterol level increases risk Calculate BMI BMI above 30 increases risk