B1- OCR Gateway Biology Science
- Created by: Georgia
- Created on: 29-12-11 18:51
Biology
Healthy- no infections or disease
Fit- how well you can perform physical tasks… strength, speed, agility, flexibility, stamina
Cardiovascular efficiency- ability of heart to supply muscles with oxygen… measured by stamina
Blood pressure- pressure is needed to pump blood to body parts…
Low blood pressure -poor circulation -tissues get less food and oxygen fainting
High blood pressure -smoking -overweight -too much alcohol -stress
Blood vessels burst -strokes -brain damage -kidney damage
Smoking- carbon monoxide combines with haemoglobin in red blood cells, instead of oxygen- heart rate has to increase to get enough oxygen to tissues… heart contracts more… increases blood pressure.
· Nicotine increases heart rate… heart contracts more often… increases blood pressure.
Poor diet- cholesterol=fatty substance and high salt levels
Some cholesterol for making cell membranes… too much- build up in arteries
Makes plaques in artery wall… narrow arteries- restricts blood flow… heart attack.
Narrow arteries… 1) heart muscles supplied with blood- coronary arteries
2) narrowed- blood flow restricted… heart muscle gets less oxygen
3) a thrombosis (blood clot) also restricts blood flow
4) if a thrombosis occurs in an already narrow coronary artery, blood flows to the heart might be blocked completely
5) area of heart muscle will be cut off from oxygen supply- heart attack
Balanced diet- supplies all essential nutrients
Nutrients
Functions
Made of
Stored
Carbohydrates
Provide energy
Simple sugars e.g. glucose
Liver as glycogen OR converted to fats
Fats
Provide energy store, insulations
Fatty acids and glycerol
Under skin OR around organs as adipose tissue
Proteins
Growth and repair of tissue, emergency energy
Amino acids
Not stored
Vitamins and minerals
Various functions e.g. vitamin C prevents scurvy; iron (mineral) makes haemoglobin for healthy blood
Water
Prevent dehydration
Some amino acids- not made by body… have to get from diet- essential amino acids.
All essential amino acids can be attained by eating meat (produced by animals) - first class proteins.
Plant proteins don’t contain all essential amino acids- second class proteins.
Diet factors-
Children and teenagers-more protein needed for growth
Older people- more calcium to protect from degenerative bone diseases e.g. osteoporosis.
Active people- more protein for muscle development and more carbohydrate for energy
Females need more iron- iron lost in menstrual blood
₂₂₂₂
Different diets… religious, e.g. Hindus don’t eat cows, sacred… personal, e.g. vegetarians, cruel to eat meat… medical reasons, intolerance or allergies
Too little protein- kwashiorkor… swollen stomach
Overpopulation- demand for protein-rich food is more than amount that’s available
Money- not enough to invest in agriculture… without good farming techniques cannot grow enough protein-rich food
EAR (Estimated Average daily Requirement) of protein (g) = 0.6 x body mass (kg)
Teenagers- more, growing
Pregnant and lactating women- more, baby needs it
Anorexia and bulimia… poor…
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