Topic 1 - Lifestyle, Health and Risk Flashcards

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1
Q

Give features of a mass transport system.

A
  • Vessels
  • Transport medium
  • Maintains speed
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2
Q

Why do some organisms require a mass transport system?

A

Larger animals have a smaller surface area to volume ratio and a higher metabolic rate. Diffusion alone is insufficient to supply all cells with the substances they need.

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3
Q

What makes water a dipolar molecule?

A

O is more electronegative than H, so attracts the electron density in the covalent bond more strongly. Forms O delta- (slight negative charge) and H delta+ (slight positive charge).

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4
Q

How is water used in transport?

A

Due to its polar nature it acts as a solvent, allowing transport of biological molecules.

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5
Q

How does public perception of risk differ from actual risk?

A
  • People overestimate risk if something is not under their control, is unfamiliar, or has particularly sever consequences.
  • People underestimate risk if something only has an effect in the long-term.
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6
Q

Give some ethical issues surrounding the use of invertebrates in research.

A

Some consider it wrong to harm any living creature. However others argue that invertebrates are not complex enough to suffer stress or pain.

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7
Q

Draw a diagram of the human hear, including names of chambers, vessels and valves.

A

Right side:

  • Pulmonary artery
  • Vena cava
  • Right atrium
  • Tricuspid valve
  • Right ventricle

Middle:
- Semilunar valve

Left side:

  • Aorta
  • Pulmonary vein
  • Left atrium
  • Bicuspid valve
  • Left ventricle
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8
Q

Relate the structure of the heart’s chambers to their function.

A
  • Atria: thin-walled and elastic, so they can stretch when filled with blood.
  • Ventricles: thick muscular walls pump blood under high pressure. The left ventricle is thicker than the right because it has to pump blood all the way around the body.
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9
Q

Describe the function of the heart’s major blood vessels.

A
  • Vena cava = brings deoxygenated blood from the body to the heart.
  • Pulmonary artery = takes blood from the heart to the lungs.
  • Pulmonary vein = brings oxygenated blood from the lungs to the heart.
  • Aorta = takes blood from the heart around the body.
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10
Q

Relate the structure of arteries to their function.

A

Thick, muscular walls to handle high pressure without tearing. Elastic tissue allows recoil. Narrow lumen to maintain pressure.

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11
Q

Relate the structure of the veins to their function.

A

Thin walls due to lower pressure. Require valves to ensure blood doesn’t flow backwards. Have less muscular and elastic tissue as they don’t have to control blood flow.

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12
Q

Relate the structure of capillaries to their function.

A
  • Walls only one cell thick; short diffusion pathway.
  • Very narrow, so can permeate tissues and red blood cells can lie flat against the wall, effectively delivering oxygen to tissues.
  • Numerous and highly branched, providing a large surface area.
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13
Q

Describe what happens during cardiac diastole.

A

The heart is relaxed. Blood enters the atria, increasing the pressure and pushing open the atrioventricular valves. This allows blood to flow into the ventricles. Pressure in the heart is lower than in the arteries, so semilunar valves remain closed.

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14
Q

Describe what happens during atrial systole.

A

The atria contract, pushing any remaining blood into the ventricles.

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15
Q

Describe what happens during ventricular systole.

A

The ventricles contract. The pressure increases, closing the atrioventricular valves to prevent backflow, and opening the semilunar valves. Blood flows into the arteries.

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16
Q

What causes atherosclerosis?

A

Endothelium becomes damaged which leads to an inflammatory response and possible blood clotting. Substances in the blood build up and harden into a plaque that narrows the artery and raises blood pressure.

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17
Q

Why does blood need to clot?

A
  • Prevents blood loss.
  • Prevents entry of harmful bacteria.
  • Provides a framework for repair.
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18
Q

Explain the process of blood clotting.

A
  1. Platelets release thromboplastin in response to damage.
  2. Causes prothrombin to change to its active form, thrombin.
  3. Turns soluble fibrinogen into insoluble fibrin, forming a mesh that traps blood cells.
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19
Q

How can blood clots be detrimental to health?

A

May restrict blood flow which can mean tissues don’t get the oxygen supply needed. In the case of atherosclerosis, a person may even develop cardiovascular diseases such as angina, stroke, heart attack.

20
Q

Give factors that increase the risk of cardiovascular disease.

A

Genetics (predispositions), age (older or more at risk), gender (men more at risk), diet, high blood pressure, high cholesterol levels, smoking, physical inactivity, obesity.

21
Q

Give three treatments for ardiovascular disease.

A
  • Antihypertensive (ACE Inhibitors, calcium channel blockers, diuretics)
  • Statins
  • Platelet inhibitors (anticoagulants)
22
Q

Give benefits and risks of antihypertensive medication.

A

+ Reduces risk of kidney failure, lowers blood pressure, increases volume of urine to get rid of excess fluids.
- Side effects include dizziness, arrhythmia and nausea.

23
Q

Give benefits and risks of statins.

A

+ Lowers cholesterol, minimal risk of side effects.

- Side effects that do appear tend to be severe e.g. muscle pain, liver damage, increase risk of diabetes, memory loss.

24
Q

Give benefits and risks of platelet inhibitors.

A

+ Prevents blood clots to limit narrowing of arteries, also effective within arteries.
- Prone to heavy bleeding even from small injuries.

25
Q

Differentiate between correlation and causation.

A
Correlation = where a change in one variable occurs at the same time as a change in another variable.
Causation = where a change in one variable causes a change in another variable.
26
Q

Why is the difference between correlation and causation important?

A

Just because two factors correlate does not mean one causes the other. There could be a third variable causing the change in one of the variables.

27
Q

Give features of a good scientific study.

A
  • Clear aim or hypothesis.
  • Representative sample.
  • Valid and reliable results.
28
Q

How might we obtain a representative sample?

A
  • Select a sample large enough to reflect the size of the target population.
  • Randomly select participants to avoid sampling bias.
29
Q

How might we ensure results are valid and reliable?

A
  • Control extraneous variables that may influence results.
  • Repeat study using the same method to check the same results are produced.
  • Use a representative sample.
30
Q

How does public perception of risk differ from actual risk?

A
  • People overestimate risk if something is not under their control, is unfamiliar, or has particularly severe consequences.
  • People underestimate risk if something only has an effect in the long-term.
31
Q

Give some ethical issues surrounding the use of invertebrates in research.

A

Some consider it wrong to harm any living creature. However others argue that invertebrates are not complex enough to suffer stress or pain.

32
Q

What are the consequences of energy imbalance?

A

If a greater amount of energy is burned through exercise than is consumed, it leads to weight loss. If a greater amount of energy is consumed than is burned through exercise, it leads to weight gain.

33
Q

What do carbohydrates consist of?

A

Chains of single units, called saccharides. Contains only carbon, hydrogen and oxygen.

34
Q

Differentiate between the types of saccharides.

A
  • Monosaccharide = single sugar monomer.
  • Disaccharide = two monosaccharides.
  • Polysaccharide = many monosaccharides.
35
Q

How are di and polysaccharides formed?

A

Monosaccharides join to form di and polysaccharides through condensation reactions (meaning a molecules of water is released). Glycosidic bonds are formed. Can be broken by adding water (hydrolysis).

36
Q

Give two examples of monosaccharides and their functions.

A
  • Glucose (six carbon atoms), main substrate for respiration.
  • Ribose (five carbon atoms), component of DNA and RNA.
37
Q

Give three examples of disaccharides and their component monosaccharides.

A
  • Maltose (two glucose molecules)
  • Sucrose (glucose + fructose)
  • Lactose (glucose + galactose)
38
Q

Give two examples of polysaccharides and their function.

A
  • Glycogen
  • Starch
    Both energy storing molecules (glycogen in animals, starch in plants).
39
Q

Relate the structure of glycogen to its function.

A

Highly branched, meaning the molecule can be easily hydrolysed to release energy quickly.

40
Q

Relate the structure of starch to its function.

A

Mixture of two polysaccharides;

  • Amylose = coiled to make the molecule compact, so large amounts can be stored.
  • Amylopectin = highly branched, so energy can be released quickly.
41
Q

Explain how a triglyceride is formed.

A

One molecule of glycerol forms ester bonds with three fatty acids through condensation reactions.

42
Q

Differentiate between saturated and unsaturated fats.

A
  • Saturated fats have no C=C bonds, and are solid at room temperature due to strong intermolecular forces.
  • Unsaturated fats have one or more C=C bonds, and are liquid at room temperature due to weak intermolecular forces.
43
Q

What is meant by a high-density lipoprotein?

A

Made of triglycerides from unsaturated fats combined with protein. Reduces blood cholesterol by transporting it to the liver to be broken down. They are known as ‘good’ lipoproteins.

44
Q

What is meant by a low-density lipoprotein?

A

Made of triglycerides from saturated fats combined with protein. Blocks receptor sites, reducing cholesterol absorption.. They are known as ‘bad’ lipoproteins.

45
Q

How do LDLs contribute to risk of cardiovascular disease?

A

The high blood cholesterol level caused by the LDLs leads to formation of atherosclerosis plaques. This is a causal relationship.