Snab Biology - Topic 1: 'lifestyle, Health And Risk'

Front 1

Polarity of water molecules

Back 1

The oxygen end is d-, and the hydrogen end is d+

Hint 1

Which atoms are more electronegative?

Front 2

Properties of water

Back 2

Dipole, excellent solvent of POLAR and CHARGED molecules, hydrogen bonding, high specific hear capacity, cohesion.

Hint 2

Think about the transport medium and the reasons why water is useful in the body.

Front 3

Mass transport system

Back 3

Comprised of the heart and circulatory system, this overcomes the limits of diffusion.

Front 4

The structure of arteries

Back 4

Thick walls with smooth muscle, elastic fibres and collagen. The wall is lined with a smooth layer of endothelial cells and the lumen is narrow.

Front 5

The function of arteries

Back 5

Take blood away from the heart. Can withstand high systolic pressures. Smooth muscle can alter the rate of blood flow by changing diameter of artery (vaso-dilation/constriction.) has a low friction surface.

Front 6

The structure of capillaries

Back 6

Very thin (one cell thick) walls. About 10 micrometers across.

Front 7

The function of capillaries

Back 7

Allow rapid exchange of materials between blood and tissue fluid. The thin walls allow quicker diffusion. They can form capillary beds anywhere die to small size.

Front 8

The structure of veins

Back 8

Thin walls with little smooth muscle, elastic tissue or collagen fibres. The wide lumen is lined with valves.

Front 9

The function of veins

Back 9

The blood inside is under low pressure, so there is less need for reinforcement. The valves stop backflow. The wide lumen allows the volume of veins to be very high, and so act as a blood reservoir.

Hint 9

High volume allows what?

Front 10

Important factors in diffusion

Back 10

Surface area, thickness of membrane, concentration gradient across membrane

Hint 10

Fick's Law

Front 11

The structure and function of the lungs

Back 11

Gas exchange occurs through multiple alveoli, maximising surface area. The membranes are very thin and the concentration gradient of gases is very high. Therefore, has exchange is rapid.

Front 12

Why do we use daphnia?

Back 12

They are abundant and easily obtained for experimental use. Being transparent allows easy observation. They have a heart, but a simple nervous system which causes them to feel limited stress/fear.

Front 13

Factors for success in the daphnia experiment

Back 13

One much immobilise the daphnia, control other variables (size of specimens, temperature and light, genders, pH,) make an accurate measurement of heart rate, and repeat the experiment many times.

Front 14

Arteries are separated from the ventricles by:

Back 14

Semilunar valves.

Front 15

The atria and ventricles are separated by:

Back 15

Atrioventricular valves.

Front 16

Valves are closed by:

Back 16

Blood pressure on the reverse side.

Front 17

Structures in the heart

Back 17

Front 18

The cardiac cycle

Back 18

First, atrial, then ventricular systole. Then diastole as the heart relaxes.

Front 19

The usefulness of blood clotting

Back 19

It can prevent blood loss and infection, and allows repair to take place.

Front 20

Blood clotting sequence

Back 20

Platelets release thromboplastin, a clotting factor. In the presence of calcium ions and vitamin K, TP converts prothrombin into active thrombin. This then converts soluble fibrinogen into insoluble fibrin, forming a fibrous net creating a clot from blood debris and cells.

Front 21

Atherosclerosis sequence

Back 21

Front 22

Stroke is:

Back 22

When blood to the brain is cut off by a clot or dislodged fatty deposit.

Front 23

Heart attack is:

Back 23

When coronary blood vessels are blocked and the heart has no blood supply. Cardiac arrest.

Front 24

Angina is:

Back 24

When coronary blood vessels narrow. Accompanied by chest pains.

Front 25

Peripheral vascular disease is:

Back 25

Narrowing of peripheral and limbic arteries and veins, including thrombosis.

Front 26

Risk factors in CVD include:

Back 26

Genetics, age, gender, blood pressure and lifestyle factors.

Front 27

Lifestyle factors in CVD include:

Back 27

Smoking, alcohol intake, exercise, dietary factors such as cholesterol and saturated fat.

Front 28

Medical treatments (and their effects) of CVD include:

Back 28

Antihypertensitives which reduce high blood pressure. Reducing blood cholesterol through the use of statins. Inhibiting blood clotting through the use of anticoagulants or platelet inhibitors.

Hint 28

Blood clotting, blood pressure and cholesterol are all factors.

Front 29

The risks of antihypertensives:

Back 29

Diuretics can cause dizziness and nausea and muscle cramps. Beta-blockers have a link with diabetes. ACE inhibitors have associations with coughs, dizziness, heart arrhythmia and impaired kidney function.

Front 30

The risks of statins:

Back 30

Muscle aches, nausea, constipation and diarrhoea; very rarely inflammation to the liver.

Front 31

The risks of anticoagulants:

Back 31

If bleeding occurs, it may be uncontrolled.

Front 32

Monosaccharides include; their properties are:

Back 32

glucose galactose and fructose. All are soluble and have an osmotic effect. They all function as quick release energy.

Front 33

Sucrose is:

Back 33

A disaccharide comprised of glucose and fructose. Soluble.

Front 34

Lactose is:

Back 34

Comprised of glucose and galactose. Soluble.

Front 35

Maltose is:

Back 35

Glucose and glucose. Soluble.

Front 36

Amylose is:

Back 36

Found in starch. Helical shape with no branches. It is insoluble and has no osmotic effect.

Front 37

Amylopectin is:

Back 37

Found in starch. It is helical and branched. It is in soluble and has no osmotic effect. As there are many terminal groups it can be broken down quickly. It is a compact storage molecule.

Front 38

Glycogen is:

Back 38

Found in animals bacteria and fungi. It has branched chains of glucose molecules. It is compact, insoluble and has no osmotic effect.

Front 39

Saccharides are joined by:

Back 39

Glycosidic bonds. This is formed during a condensation reaction. Hydrolysis can break the sugars apart again.

Front 40

The structure of lipids:

Back 40

A glycerol backbone and three fatty acid chains, joined by ester bonds. Variation occurs in the type of fatty acid chains.

Front 41

Saturated fats:

Back 41

Strong intermolecular bonds and a solid at room temperature .The chain is straight. These contain the most energy of any triglyceride.

Front 42

Unsaturated and polyunsaturated fats:

Back 42

Weak intermolecular bonds and a liquid at room temperature. The chain is kinked. These contain less energy than saturated fats. Polyunsaturated fats have multiple double bonds.

Front 43

Genetics and CVD: (3 points)

Back 43

Genetics can cause a tendency to high blood pressure and poor cholesterol metabolism. Arteries can be more easily damaged.

Front 44

Gender and CVD: (1 point)

Back 44

Oestrogen protect women against CVD up until menopause.

Front 45

Age and CVD: (2 points)

Back 45

Elasticity and width of arteries decreases as one grows older.

Front 46

Diet and CVD: (3 points)

Back 46

Excesses in saturated fats, cholesterol and lipoprotein are risk factors to CVD.

Front 47

LDLs; formation, association:

Back 47

Formed from saturated fats, protein, and cholesterol. Associated with the formation of atherosclerosis. Should be maintained at a low level.

Front 48

HDLs; formation, association:

Back 48

Formed from unsaturated fats, proteins, and cholesterol. Transport cholesterol from body tissues to the liver for breakdown. These reduce blood cholesterol level and discourage atherosclerosis. Be maintained at a high level.

Front 49

BMI formula:

Back 49

Body mass divided by height squared.

Front 50

Cohort studies: (4 points)

Back 50

Large number of people is followed over a long time period. Those who develop the condition are put into one group; various risk factors are then looked at by interviewing and correlations are searched for.

Front 51

Case-control studies. (3 points)

Back 51

A group which does have a condition is compared with a group that does not. The past history of each person is investigated to try and identify risk factors. Other variables such as age and gender must be controlled.

Front 52

Causal links: (2 points)

Back 52

Correlation might imply causation but does not necessitate it. Mechanism of action may need to be found through an experiment to show causality.

Front 53

A good study should: (3 points)

Back 53

The data collected should be valid and reliable. The sample should be representative of the whole population otherwise the sample is biased. Extraneous variables should be controlled. Sample size should be as great as possible.

Front 54

Perception of risk is often affected by: (5 points)

Back 54

Ones own experience, peer pressure, the idea of destiny, anecdotal evidence, and the remoteness of the likely consequences.

Front 55

Vitamin C, use and source:

Back 55

An antioxidant which can reduce the risk of oxidative stress. Often found in fruit juices.

Front 56

Vitamin C experiment and sources of error:

Back 56

Vitamin C in fruit juice is titrated against DCPIP. DCPIP decolourises from dark blue when reduced. Errors include: bad glassware, bad experimental measurements, the endpoint is misjudged, and the vitamin C in juice cannot be added by less than one drop at a time.

Front 57

Damage to arterial endothelium may be caused by:

Back 57

Blood flowing QUICKLY under HIGH PRESSURE or by chemicals such as those in cigarette smoke.

Front 58

When designing a trial:

Back 58

Conduct on large groups, conduct over a long time, control variables which are irrelevant.

Front 59

Capillary cells are:

Back 59

Endothelial cells, one layer thick.

Front 60

Elastic fibres are in:

Back 60

The middle layer of the artery wall, which contains muscular structure.

Front 61

The mammalian heart had two sides because:

Back 61

Separate sides supply the heart and lungs, preventing the mixing of deoxygenated and oxygenated blood. This allows as much oxygen as possible to reach the places where Otis needed. It also allows a lower (safe) pressure to be maintained in the lungs.

Front 62

What types of molecule may easily permeate a cell membrane?

Back 62

Non-polar and lipid soluble.

Front 63

Globular proteins generally are:

Back 63

Quite short polypeptide chains, possessing very many polar R groups.

Front 64

tRNA function:

Back 64

Translation. Is specific to an amino acid and has a matching specific anticodon to a mRNA triplet. It transports AAs to the ribosome and keeps them in place whilst they are being joined.