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A Biology A Level > Topic 1 > Flashcards

Topic 1 Flashcards

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1
Q

What is an open circulatory system?

A
  • Blood is not close in blood vessels
  • Substances diffuse between blood and cells
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2
Q

What is a closed circulatory system?

A
  • Blood enclosed in blood vessels
  • High blood pressure
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3
Q

What is a single vs double circulatory system?

A
  • Single is where blood flows through once for each complete circuit
  • Double is where blood flows through twice for each complete circuit
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4
Q

Why do larger organisms require a mass transport system?

A
  • SA:V ratio is smaller so diffusion cannot be effective
  • A transport system facilitates mass flow
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5
Q

What is mass transport?

A
  • Bulk movement of liquids and gases in one direction
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6
Q

What does mass transport help to do?

A
  • Maintain diffusion gradients
  • Ensures cell activity
  • Movement of substances quickly
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7
Q

What is the properties of water?

A
  • Polar molecule - dipole.
  • Hydrogen end negative and oxygen end positive.
  • Hydrogen bonds between positive and negative
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8
Q

What is cohesion and adhesion and why is it important?

A
  • Cohesion is attraction between molecules if the same type. Attraction of water molecules to each other
  • Adhesion is attraction between non-alike molecules. Water molecules to charged surfaces.
  • It is important so water flows easily
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9
Q

How is water a solvent?

A
  • Water surrounds charged particles and causes them to break up
  • Water as a solvent is used as a transport medium and a reaction medium
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10
Q

What is the structure of blood vessels?

A
  • Walls contain collagen which makes them strong and durable.
  • Elastic fibres which stretch and recoil.
  • Smooth muscles allow dilation and constriction.
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11
Q

What are the features of arteries?

A
  • Narrow lumen
  • Thick walls
  • More collagen, smooth muscle and elastic fibres
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12
Q

How does the structure of arteries relate to their function?

A
  • Lots of elastic fibres recoil to maintain high blood pressure
  • Collagen to avoid damage
  • Smooth endothelial wall to reduce friction
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13
Q

What are the features of veins?

A
  • Wider lumen
  • Thinner walls
  • Less collagen, smooth muscle and elastic fibres.
  • Valves
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14
Q

What are the features of capillaries?

A
  • One cell thick endothelium for diffusion
  • Small lumen
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15
Q

How does the structure of veins relate to their function?

A
  • Less elastic fibres as blood is under lower pressure
  • Valves prevent backflow of blood
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16
Q

What is the cardiac cycle?

A
  • Events that take place within one heartbeat
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17
Q

What happens in atrial systole?

A
  • Atria contract and pressure increases
  • Atrioventricular valves pushed open forcing blood into ventricles
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18
Q

What happens during ventricular systole?

A
  • Ventricles contract and pressure increases
  • AV valves shut, semi-lunar valves open
    Blood forces into arteries and out of heart
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19
Q

What happens during diastole?

A
  • Atria and ventricles relax
  • SL valve closes so atria fill with blood
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20
Q

Why is there a difference in thickness between the right atrium wall and right ventricle wall?

A
  • The right atrium wall is thinner because of higher blood pressure required in the ventricles.
  • The right atrium only pumps blood to the ventricle but the ventricle pumps blood to the lungs
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21
Q

Why is the left ventricle wall thicker than the right ventricle wall?

A
  • It has to pump blood further around the body
  • Has to withstand high pressure
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22
Q

What is atherosclerosis?

A
  • The hardening of the arteries due to damage of the endothelium causing fatty deposit to build up
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23
Q

How does atherosclerosis develop?

A
  • Endothelium is damaged.
  • Inflammatory response means fatty deposit builds causing an atheroma.
  • Plaque builds up and hardens.
  • Causes narrowing and loss of elasticity which creates a high blood pressure.
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24
Q

What is the consequence of atherosclerosis?

A
  • Reduces elasticity in the arteries
  • Increased blood pressure
  • Reduced blood flow
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25
Q

How does the clotting cascade start?

A
  • Platelets come into contact an form long thin projections which triggers the clotting cascade.
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26
Q

What happens in the clotting cascade?

A
  • Platelets form a platelet plug.
  • Thromboplastin is released and catalyses protein prothrombin into enzyme thrombin.
  • Vitamin K and calcium must be present.
  • Thrombin catalyses fibrinogen into insoluble fibrin which causes a mesh to trap red blood cells.
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27
Q

How can atheroma’s increase the risk of blood clotting?

A
  • The plaque deposited rupture the endothelium
  • Triggering thrombosis
28
Q

How does a blood clot lead to heart attacks?

A
  • Atheromas and blood clots restrict blood flow to areas of the heart
  • Means less oxygen is received and cells cannot produce ATP or respire making them die
29
Q

How does a blood clot on the brain cause a stroke?

A
  • Reduced blood flow means oxygen/glucose will not reach cells in the brain.
  • no aerobic respiration and no ATP produced. - - The brain needs lots of ATP to function, so lactic acid produced from anaerobic respiration inhibits enzymes and is toxic
30
Q

What are risk factors?

A
  • Factors leading to an increased chance of disease
31
Q

What are factors linked to CVD?(5)

A
  • Diet - high salt and high saturated fats
  • High blood pressure - damage artery walls
  • Smoking - affects haemoglobin
  • Genetic - inherit high BP
  • Age - build up over time
32
Q

What are factors that will increase risk of CVD?

A
  • Obesity
  • High blood pressure
  • High blood cholesterol
  • Smoking
  • Diet high in fats or salts
33
Q

What is correlation?

A
  • When a change in one variable is accompanied by a change in another
34
Q

What is causation?

A
  • When a change in one variable is caused by a change in another
35
Q

What is a risk?

A
  • The chance/occurrence of an unwanted event
36
Q

What are the types of medication used to treat CVD?

A
  • Statins
  • Anticoagulants
  • Platelet inhibitors
  • Antihypertensives
37
Q

How do antihypertensives work?

A
  • Lower blood pressure to reduce risk of arterial damage
  • Reduce heart rate and prevent muscles in vessel walls contracting
38
Q

How do anticoagulants work?

A
  • Reduce the risk of a blood clot forming which inhibits platelet production
39
Q

How do Statins work?

A
  • Inhibit production of LDL cholesterol to stop atherosclerosis
40
Q

How do platelet inhibitors work?

A
  • Reduce blood clotting by preventing platelets from becoming activated
41
Q

What are the benefits and risk of statins?

A
  • Benefits: reduce atheroma development of atheroma, increase HDL’s
  • Risks: Taken long term, side effects of tiredness vomiting and muscle weakness
42
Q

What are the benefits and risks of anti-hypertensives?

A
  • Benefits: Reduce blood pressure, measured at home
  • Risks: Headaches, drowsiness, heart palpitations
43
Q

What are the benefits and risks of anticoagulants?

A
  • Benefits: reduce formation of blood clots and reduce size of any existing blood clots
  • Risks: excessive bleeding
44
Q

What are the benefits and risks of platelet inhibitors?

A
  • Benefits: reduce formation of new blood clots
  • Risks: coughing, dizziness, excessive bleeding, liver dysfunction
45
Q

What are cohort studies?

A
  • Follow the group of people without disease to see who develops it over time
46
Q

What are case studies?

A
  • Look at the histories of risk factors for those who currently have the disease
47
Q

What are carbohydrates?

A
  • Biological macromolecules made of C, O and H atoms
48
Q

What are monosaccharides?

A
  • Single sugar monomers
  • Formula = (CH2O)n
  • Glucose, fructose, galactose
49
Q

What is glucose?

A
  • Hexose sugar
  • Formula = C6H12O6
  • Alpha glucose and beta glucose
50
Q

What is a glycosidic bond?

A
  • A bond when two hydroxyl (OH) groups on monosaccharides join
  • Formed via condensation reaction
51
Q

What are disaccharides?

A
  • Two monosaccharides joined via condensation reaction
  • Glycosidic bonding
  • Maltose, sucrose, lactose
52
Q

What are polysaccharides?

A
  • Chain of monosaccharides joined by glycosidic bonds in a condensation reaction
  • Starch, cellulose, glycogen
53
Q

Why are polysaccharides a good energy store?

A
  • Compact
  • Insoluble
  • Rapidly hydrolysed
54
Q

What does starch consist of?

A
  • Amylose
  • Amylopectin
55
Q

What is amylose?

A
  • Alpha glucose
  • Joined by 1,4 glycosidic bonds
  • Chain coils into helix shape and is compact
56
Q

What is amylopectin?

A
  • Alpha glucose
  • Joined by 1,4 and 1,6 glycosidic bonds
  • Branched structure for quick release and rapidly hydrolysed
57
Q

What is the structure of glycogen?

A
  • Highly branched 1,4 and 1,6 glycosidic bonds
  • More terminal glucose molecules which are added or removed by rapid hydrolysis
58
Q

What are lipids?

A
  • Macromolecules
  • Large, complex and non polar molecules
  • For energy storage, insulation and hormones
59
Q

What is a triglyceride?

A
  • Formed of one molecule of glycerol and three fatty acids in condensation reaction
60
Q

What bond links each fatty acid and the glycerol?

A
  • Ester bond
61
Q

What do triglycerides form?

A
  • Three molecules of water
  • One ester bond
62
Q

What are the properties of saturated fats?

A
  • Single carbon bonds (C-C) in hydrocarbon chain
  • Straight chains with strong intermolecular forces
  • Solid at room temp
63
Q

What are the properties of unsaturated fats?

A
  • Double carbon bonds (C=C) in hydrocarbon chain
  • Kinked structure so weaker intermolecular forces
  • Liquid at room temp
64
Q

What are HDL’s?

A
  • High density lipoproteins (good cholesterol)
  • Unsaturated fats
  • Transports cholesterol from body tissue to liver where it is excreted
  • Reduce blood cholesterol when too high
65
Q

What are LDL’s?

A
  • Low density lipoproteins (bad cholesterol)
  • Saturated fats
  • Moves cholesterol from liver into bloodstream
66
Q

How is obesity measured?

A
  • BMI
  • Waist to hip ratio
67
Q

What factors should be taken into consideration when analysing data?

A
  • Sample size
  • Individuals
  • Control group
  • Influence of variables

A Biology A Level (8 decks)

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