BIOLOGY TOPIC 2 - ORGANISATION

• what is the 'lock and key theory'?


  an enzyme's active site is complementary to the shape of its substrate
• what does amylase do and where is it found?


  breaks down carbohydrates into simple sugars

  pancreas and salivary glands
• what does protease do and where is it found?


  breaks protein down into amino acids

  small intestine, pancreas and stomach
• what does lipase do and where is it found?

  break down fats into fatty acids and glycerol

  pancreas, mouth and stomach
• how does bile speed up breakdown of fats?


  emulsifies fats to form droplets which increases surface area
• where is bile made and stored?

  made in liver

  stored in gallbladder
• where does the aorta carry blood to?


  from the heart to the body
• where does the vena cava carry deoxygenated blood to?


  from the body to the heart
• where does the pulmonary artery carry blood to?


  from the heart to the lungs
• where does the pulmonary vein carry blood to?


  from the lungs to the heart
• what does the coronary artery do?


  supplies blood to the heart muscle
• where are pacemaker cells found?


  right atrium
• what is coronary heart disease?


  layers of fatty material build up inside the coronary arteries, narrowing them
• advantages and disadvantages of stents


  advantages = long term solution, can't be rejected

  disadvantages = risk of infection/complications from surgery, scar tissue forming
• advantages and disadvantages of statins


  advantages = lowers cholesterol, no surgery required

  disadvantages = drugs can have side effects, have to be taken long term, don't work instantly
• advantages and disadvantages of biological replacement valves


  advantages = less likely to clot

  disadvantages = more likely to wear out, can be rejected, patient will have to take immunosupressants
• advantages and disadvantages of mechanical replacement valves


  advantages = last longer, can't be rejected

  disadvantages = clots may develop
• what is cancer?


  uncontrolled cell growth and division
• what's the difference between malignant and benign tumours?


  benign = contained within membrane

  malignant = invade neighbouring tissues and spread through the body through blood
• gcse definition of health


  the state of physical and mental wellbeing
• what lifestyle factors impact cardiovascular diseases?


  poor diet, lack of exercise, smoking
• what do epidermal tissues do in plants?


  protect from water loss
• what do palisade mesophyll do in plants?


  absorb light energy
• what do spongy mesophyll do in plants?

  gas exchange
• what do xylem do?

  transport water from roots to plants
• what do phloem do?

  transport food to where it is needed
• what do guard cells do in plants?

  control gas exchange and water loss