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B1 Revision Notes

Diet and Energy

  • Carbohydrates are for energy
  • Fats are for energy and making cell membranes
  • Proteins are for growth, making new cells, repair and energy
  • Vitamins and minerals are for keeping healthy
  • Fibre is to keep the digestive system working well
  • Water is to transport other nutrients
  • Metabolic rate is the rate at which reactions take place in the cells in your body.
  • Generally
    • men have faster metabolic rates than women
    • young people have faster metabolic rates than old people
    • the more muscle to fat you have the higher your metabolic rate will be

Diet, Exercise and Health

  • Your liver makes cholesterol. It's needed to make cell membranes
  • Too much cholesterol is bad for you because it forms blockages in blood vessels, restricting blood flow, that can lead to heart disease
  • Saturated fats can increase cholesterol and unsaturated decrease it,
  • Saturated fats are in animal products and unsaturated are in plant products
  • Inherited factors effect cholesterol levels
  • A high level of cholesterol increases the risk of plaques around the walls of your arteries. This slows downs the blood so it clots. The clot or part of the plaque breaks of and gets carried in the blood. This then blocks a smaller vessel, blocking blood flow
  • Sometimes a clot blocks one of the arteries that take oxygenated blood to the heart. This causes a heart attack.
  • Low-density lipoprotein (LDL) is bad cholesterol and can cause heart disease
  • High-density lipoprotein (HDL) is good cholesterol because HDLs protect against heart disease. They help remove cholesterol from the walls of the blood vessels.
  • Diabetes
    • increases risk of heart attacks
    • In type 2 diabetes, blood sugar levels rise because certain cells in the body do not respond properly to the hormone insulin
    • a healthy lifestyle decreases the risk of diabetes

Pathogens and Infections

  • Pathogens are micro-organisms that cause disease
  • Bacteria can reproduce rapidly in the body and produce toxins that get carried around in your blood.
  • Viruses reproduce in body cells. They then burst out of the cell, destroying it
  • An epidemic is when a wide range of people have a disease
  • A pandemic is when a disease effects a whole country, or even spreads worldwide
  • Semmelweiss
    • Hungarian doctor that worked in an Austrian hospital in the 1840's
    • There were 2 wards: one with medical students and one with midwives
    • Women were dying of puerperal fever just after giving birth normally. 
    • A professor was accidentally cut with a knife and later died of similar symptoms. 
    • Semmelweiss released disease spread through contact so made all the doctors wash their hands
    • The death rate went down

Fighting Infection

  • White blood cells destroy pathogens
    • Phagocytes take the bacteria into their cytoplasm and kill them. It's called engulfing them
    • Lymphocytes make antibodies or antitoxins to match a bacterium's toxins exactly. These counteract the toxins the bacterium makes

Drugs against disease

  • Painkillers are over the counter or prescribed to reduce pain but they don't cure anything
  • Antibiotics are drugs that kill bacteria inside your body without…



Thank you really helped me a lot! XD

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