Topic 1

Question 1

Explain why many animals need a heart and circulatory system

Answer 1

• heart needed to pump/move blood around the body
• many animals have a small surface area ratio to volume
• a circulatory system is needed to overcome limitations of diffusion
• blood needs to pump molecules around body

Question 2

Explain what is meant by a double circulatory system?

Answer 2

• blood flows twice through the heart for one circuit
• blood goes through heart to lungs and rest of the body

Question 3

What are the properties of water that make it an ideal transport medium ?

Answer 3

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

Question 4

What is the difference between arteries and capillaries

Answer 4

• arteries have thick wall where as caps are one cell thin
• arteries have lots of collegen where as caps have none
• arteries have lots of muscle where as caps have none
• arteries have lots if elastic tissue where as cap have none

Question 5

Explain how the structure of an artery wall is adapted to both withstand and maintain high blood pressure

Answer 5

• lots of collagen which provides strength to withstand pressure
  -muscle tissue allows contraction of lumber
• elastic fibres stretch and recoil which allows lumen to grow and go back

Question 6

Explain how the structure of a vein relates to its function

Answer 6

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

Question 7

Describe the Cardiac cycle

Answer 7

The cardiac cycle consists of three stages: atrial systole, ventricular systole and diastole.
During atrial systole, the atria contract forcing atrioventricular valves open and blood flows into ventricles
During ventricular systole, ventricles contract, semi lunar valves open as oxygenated blood is forced out of the heart through the aorta to the body and through the pulmonary artery to the lungs.
Diastole - atria and ventricles relax, semi lunar valves close

Question 8

Explain differences between pressure changes in left atrium and left ventricle during cardiac cycle

Answer 8

• pressure changes are smaller in atrium than in ventricle
• the atrium has less cardiac muscle than ventricle
• the atrium does not have to use blood as far as ventricle has to
• the increase in pressure happens in the atrium before ventricle
  -atrial systole has to happen before venatical system in order for the ventricle to fill with blood
  -therefore increasing the atrial pressures which increases pressure in ventricles

Question 9

Describe how atherosclerosis occurs

Answer 9

• damage to endothelial cells
• inflammatory response
• large white blood cells enter
• build up of cholesterol
• atheroma forms
• Calcium salts and fibrous tissue present
• elasticity reduced
• artery narrows
• blood pressure increases

Question 10

How does blood clotting process occur

Answer 10

-thromboplastin released which starts cascade
- concerts prothrombin to thrombin
- catalysed conversion of fibrinogen to fibrin
- firin creates mesh fibres
-platelets and blood cells get trapped in mesh
-form a blood clot

Question 11

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

Answer 11

• high salt intake
• increases blood pressure
• high blood pressure damages entholeoum
• higher intake on saturated fats / LDLS increase risk f atheroma forming

Question 12

Describe the roll of LDLS in the development of atherosclerosis

Answer 12

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

Question 13

Describe how very high blood pressure could result in atherosclerosis

Answer 13

• high blood pressure damages endothelium of artery
• this causes a inflammatory response
• white blood cells and cholesterol accumulate
• Atheroma forms
  -calcium slates and fibrous tissue build up
  -Plaque is formed

Question 14

Explain how atherosclerosis can result in damage to heart muscle

Answer 14

-narrowing of lumen in arteries
- reduced blood flows and oxygen to cardiac muscles
- reduces aerobic respiration

Question 15

Explain why high level of sugar in a persons diet could lead to obesity

Answer 15

-energy intake higher than energy output
-excess sugar can be stored as fat
- leads to weight gain
- obesity indicates by BMI above 30 or was it it hip ratio

Question 16

Devise a procedure to compare the effects of decaffeinated coffee and regular coffee on the heart of daphnia

Answer 16

• describe the procedure
  -record heartbreak before and after placing in decaf or reg
• controlled variable for coffee
• refinance to IV/DV
• calculate mean etc

Question 17

Give one structural difference between amylose and amylopectin

Answer 17

-amylose is unbranches and 1,4 glycosidic bonds
-amylopectin branched and has 1,4 and 1,6 glycosidic bonds

Question 18

Describe the formation of glycogen from glucose

Answer 18

• joined i condensation reaction
• formed 1,4 and 1,6 glycosidic bonds

Question 19

Explain how the structure of glycogen allows it to be an energy store

Answer 19

• • polymer of glucose
• provides glucose for respiration
• branched - rapid hydrolysis
  -1,6 glucose bonds
• compact it allow large amounts of energy to be stored in small place
• insoluble - doesn’t effect osmosis

Question 20

Compare and contrast the structure of a disaccharide with glycogen

Answer 20

-both contain carbon, hydrogen and oxygen
- both contain glycosidic bonds
-bonds contain glucose
BUT
-glycogen contains 1,4 and 1,6 where as disaccharide only have one type
- glycogen only contains glucose where as disaccharides contain glucose and other monoscharrdis

Question 21

Compare the structure of amylose, amylopectin and glycogen

Answer 21

-amylose - alpha glucose, 1,4 gb, spiral shaped, not branched and energy store in plants
-amylopectin - alpha glucose, 1,4/1,6 gb , spiral shaped, is branched, energy store in plants
-glycogen - alpha glucose, 1,4/1,6 , spiral ish , is branched, energy store in animals

Question 22

Explain the benefits of statins to human health

Answer 22

• lower blood cholesterol
• inhibition of cholesterol synthesise in liver
• reduce risk of cvd

Question 23

Explain how anticoagulants can help reduce the effects of CVD

Answer 23

-prevent the formation of blood clot
-reduces the stickiness of plates
-clotting factors are not sythsies
- risk of blood vessels is reduced

Question 24

What is the risk of anticoagulants

Answer 24

Internal bleeding
Stomach uclers

Question 25

Explain the role of anti hypertensive drugs

Answer 25

-antihypertensive drugs lower blood pressure
- lower blood pressure reduced risk of damage to endothelium
- reduces risk of inflammatory response
- reduced risk of atheroma forming

Question 26

State 2 possible side effects of taking drugs to reduce BP

Answer 26

• Nausea
  -muscles cramps
  -kidney failure
• dizziness

Question 27

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

Answer 27

• they would reduce the risk of blood clots forming
• therefore less likely that the blood flow to heart muscle will be blocked

Question 28

Describe how high blood pressure could be reduce by medication and lifestyle changes

Answer 28

• antihypertensice drugs
• reduce salt in take
  -stop smoking
• reduce weight
  -increase excersie

Question 29

What is produced when sucrose is broken down

Answer 29

Glucose and fructose