Atherosclerosis And Cardiovascular Disease

Damage to endothelium triggers an inflammatory response; white blood cells move into the artery wall; they accumulate LDL cholesterol forming foam cells; calcium salts and fibres deposit, forming a hardened plaque

Plaque narrows lumen / restricts blood flow; this raises blood pressure; raised blood pressure damages endothelium further (causing more plaque formation in a positive feedback cycle)

Cholesterol / LDL / fatty material; calcium salts / fibrous tissue / dead foam cells

Thrombin converts (soluble) fibrinogen into (insoluble) fibrin

Atherosclerotic plaque damages the endothelium / exposes collagen; platelets stick to the damaged surface; this triggers the clotting cascade / thromboplastin release, leading to thrombus formation

A thrombus is a clot that forms in a blood vessel; an embolism is a clot that has broken away and travelled through the circulation to block a vessel elsewhere

Genetics / family history; age; gender / sex (any two)

Nicotine raises heart rate and blood pressure (damaging the endothelium); carbon monoxide binds to haemoglobin, reducing oxygen delivery; chemicals in smoke damage the endothelium directly; smoking lowers HDL / raises LDL cholesterol

Non-modifiable factors include genetics, age and gender; modifiable factors include diet, smoking, inactivity and high blood pressure; high saturated fat raises LDL, which builds up in artery walls forming plaques; smoking damages the endothelium, triggering plaque formation; inactivity contributes to obesity and high blood pressure; reducing saturated fat lowers LDL cholesterol; stopping smoking allows the endothelium to recover; regular exercise lowers blood pressure and increases HDL; reducing salt intake lowers blood pressure; combining these changes slows atherosclerosis progression and lowers overall CVD risk

A substance that neutralises / removes free radicals (preventing oxidative damage)

Antioxidants neutralise free radicals; (free radicals would otherwise) damage the endothelium / oxidise LDL; reducing plaque formation / atherosclerosis (and therefore lowering CVD risk)

Fruits contain a range / mixture of antioxidants (working together); they also contain other beneficial compounds (e.g. fibre, flavonoids) not present in supplements

Blue to colourless

Orange juice contains a higher concentration of vitamin C; less juice is therefore needed to reduce / decolourise the same volume of DCPIP

Finding the concentration of vitamin C in the juice $$c=1.0\times \frac{1.2}{0.4}$$ $$c=3.0{\text{ mg/cm}}^{3}$$ The concentration of vitamin C in the juice is 3.0 mg/cm³.

Repeat each titration multiple times and calculate a mean; use a colour standard / colorimeter to judge the end point; standardise drop size; ensure all samples are at the same temperature (any two)