SNAB Biology AS Unit 1 Topic 1
A mindmap primarily for the synoptic element of the A2 paper. A broad overview of topic 1 of unit 1; lifestyle, health, and risk
- Created by: Zoe
- Created on: 30-05-13 18:39
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- AS TOPIC 1 - LIFESTYLE, HEALTH, AND RISK
- Transport and Circulation
- Water
- Good solvent
- Polar
- Hydrogen bonding
- Creates cohesion
- Why do we need transport?
- Need substances to enter and leave the body
- Small organisms: diffusion is good enough
- Big organisms: smaller SA/V ration
- Mass transport system overcomes limitations of diffusion
- Arteries, veins and capilarries
- Arteries
- Relatively thick wall
- Withstands high blood pressure
- Smooth muscle
- Alters diameter of lumen to vary blood flow
- Elastic fibres
- Allows stretching of walls
- Smooth layer of endothelial cells
- Low friction
- Narrow lumen
- Relatively thick wall
- Veins
- Relatively thin wall
- Blood under low pressure
- Very little smooth muscle/elastic fibres
- No pusle of blood so no stretching
- Wide lumen
- Large volume acts as blood resevoir
- Valves
- Prevents back flow
- Relatively thin wall
- Capillaries
- Very thin walls
- Allow rapid exchange between blood and tissues
- Very thin walls
- Arteries
- Water
- Cardiac Cycle and Heart Rate
- Atria and ventricles contract during systole and relax during diastole
- Elastic recoil of heart muscles lowers pressure in atria and ventricles
- CVD
- Blood clotting
- Minimises blood loss
- Helps prevent entry of pathogens
- Provides a framework for repair
- Damage exposes collagen fibres, to which platelets attach
- Platelets release thromboplastin
- In presence of calcium ions and vit K, thromboplastin converts prothrombin into thrombin
- Thrombin converts soluble fibrinogen into insoluble fibrin
- Fibrin traps cells and debris --> clot
- Thrombin converts soluble fibrinogen into insoluble fibrin
- In presence of calcium ions and vit K, thromboplastin converts prothrombin into thrombin
- Platelets release thromboplastin
- Fibrin traps cells and debris --> clot
- Atherosclerosis
- Positive feedback
- Damage to lining
- Inflammatory response
- Atheroma forms
- Plaque formation
- Raised blood pressure
- Damage to lining
- Inflammatory response
- Atheroma forms
- Plaque formation
- Raised blood pressure
- Raised blood pressure
- Plaque formation
- Atheroma forms
- Inflammatory response
- Damage to lining
- Raised blood pressure
- Plaque formation
- Atheroma forms
- Inflammatory response
- Stroke
- Angina
- Heart attack
- Treatment
- Antihypertensives
- Diuretics
- Lowers blood volume and pressure
- Dizziness, nausea, muscle cramps
- Beta Blockers
- Block response of heart hormones, making contractions less frequent and less powerful
- Possible link to diabetes
- ACE Inhibitors
- Block production of angiotensin, which causes arterial constriction and a rise in blood pressure
- Cough, dizziness, arrhythmia, impaired kidney function
- Diuretics
- Statins
- Lower cholesterol level in blood by blocking liver enzyme
- Muscle aches, nausea, constipation, diarrhoea, inflammation, liver failure, people stop eating healthy diet
- Anticoagulants
- Reduce risk of clot formation
- Uncontrolled bleeding, dosage control essential
- Platelet Inhibitory Drugs
- Platelets become less sticky
- Irritation of stomach lining, stomach bleeding
- Antihypertensives
- Blood clotting
- Structure and Function of Carbohydrates
- Monosaccharides
- E.g. glucose
- Disaccharides
- E.g. lactose
- Polysaccharides
- Unbranched
- E.g. amylose
- Found in starch
- Alpha glucose molecules
- Tight spirals
- No osmotic effect
- Insoluble
- E.g. amylose
- Branched
- E.g. glycogen
- Energy storage molecule
- Compact
- No osmotic effect
- Insoluble
- E.g. glycogen
- Unbranched
- Glycosidic bonds
- Formed in an condensation reaction
- Monosaccharides
- Structure and Function of Lipids
- Insoluble in water
- Soluble in organic solvents
- Triglycerides = 3x fatty acids + 1 glycerol
- Formed in condensation reactions
- Variation in Triglycerides
- Length of hydrocarbon chain
- Absence/presence and number of double bonds
- Mix of fatty acids
- Saturated Fats
- Strong intermolecular bonds
- Solid at RTP
- Straight
- Monounsaturated
- Weaker intermolecular bonds due to kink(s)
- Polyunsaturated
- Liquid at room temperature
- Polyunsaturated
- Liquid at room temperature
- Weaker intermolecular bonds due to kink(s)
- Polyunsaturated
- Risk Factors for CVD
- Genetic
- Tendency for high BP and poor cholesterol metabolism
- Mutations in genes affect HDL:LDL levels
- Gender
- Oestrogen = protection (before menopause)
- Ageing
- Elasticity and width of arteries decrease with age
- Diet
- Correlations between dietary habits and level of CVD
- High Blood Pressure
- Smoking
- CHemicals in smoke physically damage artery linings
- Causes arterial constriction
- Inactivity
- Exercise reduces blood pressure and raises HDLs
- Obesity
- Energy Balance
- BMI = Body mass in kg / (height in m) squared
- Genetic
- Correlation/ Causation
- Correlation suggests there MIGHT be a causal link
- To show causality, a mechanism by which one factor causes the other needs to be proved
- What makes a good study?
- Valid and reliable data
- Valid = accurately measure what it's supposed to
- Reliable = data that accurately measures what they are supposed to every time
- Sample representative of whole population
- Variables controlled as far as possible
- Good sample size
- Valid and reliable data
- Transport and Circulation
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