Biology topic 2

• Cell Organisation


  cell > tissue > organ > organ system > organism
• tissues


  similar cells that work together to complete a function
• Enzymes


  Catalysts for chemical reactions in living things
• Enzyme shapes


  'lock and key'

  every enzyme has an active site, with a unique shape that fits onto the substance

  
• Enzymes: temperature


  a higher temp increase the rate of reactions in enzymes, however if it gets too hot they enzymes start to deform and stop working
• Enzymes: pH


  if the pH is too high or low it affects the bonds holding together the enzyme - effects the actives sight and so denatures the enzyme.
• pH on enzymes: Practical

  1) put a drop of iodine solution on spotting tile

  2) put a water beaker on top of a Bunsen burner, heat until 35 degrees. keep temp constant

  3) use syringe to add 1cm of amylase solution to 1cm of a buffer solution with pH 5.

  4) Put tube into water beaker for 5 minutes

  5) use syringe to add 5cm of a starch solution to boiling tube.

  6) mix contents of boiling tube and start a stop watch.

  7) starting next to the control variable, use continuous sampling add the solution into the iodine solution every 30 seconds

  8) repeat with buffers of different pH
• Amylase


  Breaks STARCH into SUGARS
• Protease


  breaks PROTEINS into AMINO ACIDS
• Lipase


  breaks LIPIDS into GLYCEROL and FATTY ACIDS
• Bile


  NEUTRALISES the STOMACH ACID and emulsifies fats.

  Produced in liver
• Amylase produced in:


  - salivary glands

  - pancreas

  - small intestine
• Protease produced in:


  - Stomach

  - pancreas

  - small intestine
• Lipase produced in:


  - Pancreas

  - small intestine
• Sugars test:


  Benedict's Solution

  blue > brick red
• Starch test:


  Iodine solution

  brown-orange > blue-black
• Protein test:


  Biuret solution

  blue > purple
• Lipid test:


  Sudan III solution

  mixture will seperate - top will be Bright red.
• The Lungs

  
• Alveoli


  - tiny sacs of lung tissue specialized for the movement of gases between air and blood.

  - Oxygen diffuses into the bloodstream through them.

  - Carbon dioxide diffuses into the lungs through them
• The Heart

  
• Pacemaker


  in the RIGHT ATRIUM.

  controls the heartbeat through electrical impulses.
• Arteries


  - AWAY FROM HEART

  - SMALL LUMEN

  - THICK WALLS

  - HIGH PRESSURE
• Veins


  - INTO HEART

  - LARGE LUMEN

  - THIN WALLS

  - VALVES

  - LOW PRESSURE
• Capillaries


  - REALLY TINY

  - VERY CLOSE TO EVERY CELL

  - PERMEABLE WALLS

  - SUPPLY FOOD AND OXYGEN

  - TAKE AWAY CARBON DIOXIDE

  - WALLS ARE 1 CELL THICK
• Inside the Blood


  WHITE BLOOD CELLS: defend against infection

  PLATELETS: help blood clot

  PLASMA: carries everything in the blood

  RED BLOOD CELLS: carry haemoglobin that carries oxygen, has a biconcave disk shape
• Coronary Heart Disease


  illness of the heart caused by a blockage in the coronary arteries
• coronary heart disease: STENTS

  Keep arteries open.

  - Tubes inserted inside of arteries to keep them open

  - They push the wall out squashing the fatty deposits

  - Creates more space in the artery
• coronary heart disease: STATIN

  Reduce cholesterol in the blood

  - Having too much cholesterol can cause fatty deposits to form,

  - Statins lowers the 'bad' cholesterol in the bloodstream.
• Statins pros


  - reduce risk of strokes, heart attacks and heart diseases.

  - can increase beneficial cholesterol

  - may prevent other diseases
• Statins cons


  - must be taken regularly and so risk of forgetting

  - can cause negative side effects

  - effect is not instant
• Communicable diseases


  can be spread from person to person or animals to people.

  can be caused by virus, bacteria, protist or fungi.

  sometimes called contagious or infectious.

  e.g. measles, the flu
• non-communicable


  cannot spread between people or animals.

  generally last for a long time and get worse slowly.

  e.g. cancer, asthma
• factors affecting your health

  - diet

  - stress

  - life situation e.g. access to medicine
• risk factors increasing chance of illness


  - exercise done

  - substances in environment e.g. air pollution

  - substances in your body
• risk factors that can cause disease

  - smoking

  - obesity

  - too much alcohol consumption

  - radiation exposure
• types of Tumours


  BENIGN - tumour stays in one place rather than invading other tissues - not normally dangerous, is NOT CANCEROUS.

  
  

  MALIGNANT - tumour grows and spreads to healthy tissue. Cells can break off and spread through the blood, these form secondary tumours. Are DANGEROUS are CANCEROUS
• Risk factors of cancer: lifestyle


  SMOKING - lung cancer

  OBESITY - many different cancers

  UV EXPOSURE - radiation highers risk

  VIRAL INFECTION
• Risk factors of cancer: genetics

  can inherit faulty genes.
• inside a leaf