Organisation

• cells - basic building blocks of all living organisms
• Tissue - A group of similar cells that work together to carry out a particular function.
• Organs- groups of tissues that work together to perform a specific function.
• Organs are organised into organ systems which work together to form organisms
• Enzymes - biological catalysts that speed up chemical reactions in living organisms
• Enzymes are proteins that help speed up metabolism (the chemical reactions in the body)
• Lock & key enzymes

  • Enzymes speed up Chemical reactions to do this they have an active site, the substrate is the molecule, the enzymes react with which needs to fit perfectly into the active site & if the substrate doesn’t fit perfectly the reaction wont be catalsyed
• Factors affecting enzymes

  -temperature increases the rates of reaction

  -if the temperature gets too high/hot Some of the bonds holding the enzyme together will break, causing the enzyme to have a different shape and no substrate to be able to fit in the active site, leaving the enzyme denatured
• factors affecting enzymes

  -Enzymes have an optimum pH in which they work best at

  -the pH of enzymes is too high or low, it interferes with the bonds, holding the enzymes together. This changes the shape of the active site. leaving the enzyme denatured
• Amylase is a carbohydrates that breaks down to create starch
• Proteases is protein that breaks down to create amino acids
• Lipases which is lipids (fat) breaks down to create glycerol & fatty acids
• Bile is made in the liver & stored in the gall bladder. it is an alkaline That neutralises hydrochloric acid from the stomach. It emulsifies fats meaning it breaks it down into tiny droplets also increasing the surface area. The alkaline conditions & larger surface area increases the rate in which lipases breaks down & also digestion is faster
• Enzymes practical

  • firstly, you add drops of iodine into a spotting tile
  • You don’t have three solutions : 2 cm³ of amylase, 2 cm³ starch & 2 cm³ buffer solution
  • Set up Bunsen burner with a beaker of water on top heat till 35°C
  • In a boiling tube, mix amylase and buffer solution
  • Then add tube into the water
  • leave for five minutes
  • Then at the stratch to the solution & mix
  • Then immediately start a stopwatch
  • Then take samples using a droppin pipette
  • Add to the iodine
• Enzyme practical

  -if the iodine changes from a brownie orange to a blue black, then starch is presents

  -Practical with different pH values
• Benedict test for reducing sugars

  • Prepare your food
  • Add 5 cm³ of your food into a test tube
  • Prepare a water bath of 75°C
  • Add 10 drops of Benedict solution to your test tube
  • Then add the test tube into the water bath for five minutes
• Benedict test for reducing sugars

  -Is the colour of the food changes from the normal blue colour to yellow green or red it shows reducing sugars are present

  -The colour depends on how much sugars is in the food
• Iodine test for starch

  • Add 5 cm³ of your food into a test tube
  • Add iodine, solution & gently shake
• Iodine test for starch

  • If starch is present, the solution will change from a brownie orange to a black or blue black
• Biuret test for protein

  • Prepare your food
  • Add 2 cm³ of your food into a test
  • Add 2 cm³ of Biuret solution to your test tube & shake
• Biuret test for protein

  • if protein is present, the solution will change from blue to purple
• Sudan III test for lipids

  • Prepare your food
  • Add 5 cm³ of your food into a test tube
  • Add three drops of Sudan solution into the test tube
  • Then shake gently
• Sudan test for lipids

  • if it contains lipids to make sure separate out into two layers, the top layer will be bright red
  • If no, lipids are present, no separate red layer will form at the top of the liquid
• Lungs function & structure

  • first, breathe in air through our noses
  • It goes through our trachea
  • Then divide between our bronchi
  • Then further divides between branch structures called bronchioles the bronchioles ends at small bags called alveoli
• How the alveoli is adapted to carry out gas exchange?

  • There are many alveolis
  • Which provides a larger surface area
  • The walls of the alveoli are one cell think
  • Which provides a short diffusion path
  • Good blood supply
  • In which helps to maintain the diffusion gradient
• Heart is an organ that pumps blood around the body in a circulatory system
• Heart function & structure

  • The right ventricle pumps deoxygenated blood to the lungs where gas exchange takes place
  • The left ventricle pumps oxygenated blood around the rest of the body
• Heart

  body tissue - vena cava - right atrium - right ventricle- pulmonary artery-lungs - pulmonary vein - left atrium - left ventricle - aorta - body tissue
• The natural resting heart rate is controlled by a group of cells located in the right artrium Act as a pacemaker. Artificial pacemakers, electrical devices use to correct irregular Heart rate
• Arteries

  • A thin wall & muscles
  • Carry blood away from the heart
• Capillaries

  • Thin wall, short diffusion half full substances to go in between the blood and body cells
  • Involved in the exchange materials at the tissues
• Veins

  • thin wall & they contain valves
  • carry blood to the heart
• Blood is a tissues consisting of plasma, in which the red blood cells, white blood cells and platelets are suspended
• Red blood cells

  • Carry oxygen from the lungs to the cells in the body
  • They do not have any nucleus
  • They are shaped like a biconcave disk
• White blood cells

  • Change into phagocytosis, antibodies & antitoxins
  • they have a nucleus
• Platelets (small fragments of cell)

  • they float about in the cell & help the blood clot at a wound
  • Don’t have a nucleus
• Plasma

  • this carries everything in the blood:white blood cells, red blood cells & platelets
• Cardiovascular diseases are diseases in the heart or blood vessels
• Consequences of faulty valves

  • Less blood reaches the body
  • The valves not being able to open fully & my develop a leak
• Advantage of treating cardiovascular diseases

  • Having a transplant in surgery, could be lifesaving
  • Drugs can help you prevent other diseases