Topic 2 - B2

• What is the order of cell organisation in the body?


  similar cells -> tissues -> organs -> organ systems
• What do each of these tissues do inside the body?

  • Muscular tissue

  -> contracts to move what ever its attached to

  • Glandular tissue

  -> makes and secretes (releases) chemicals like enzymes and hormones

  • Epithelial tissue

  -> cover parts of the body like the inside of gut
• What is a catalyst?


  Is a substance which increases the speed of reaction without being changed or used up in the reaction
• What acts as a biological catalyst?


  Enzymes
• What factors affect enzymes ability to work?

  • temperature

  •pH
• Practical procedure to investigate the effect of pH on enzyme activity

  1. Place a tripod and gauze on a Bunsen burner

  2. Heat water in beaker until 35°C (use thermometer)

  3. Get spotting tile and fill spots with iodine solution

  4. Using syringe add 1cm³ of amylase and 1cm³ of buffer solution (pH 5) to test tube

  5. After five minutes add 5cm³ of starch solution to test tube

  6. Start time and every 30s using a pipette add some solution to spot on spotting tile

  7. Do this until the solution turns orange/red from blue/black and stop timer

  8. Repeat with different pHs of buffer solution and compare timings
• Independent variable (IV)

  • pH
• Dependent variable (DV)

  • Enzyme activity
• Controlled variables (CV)

  • Time, volume of amylase solution, concentration
• Starch - Amylase > maltose
• Proteins - protease > amino acids
• Lipids - lipase > glycerol + fatty acids
• What is the role of bile?


   •Neutralises stomach acid

  • Emulsifies fats
• What is the role of the salivary glands?


  Produce amylase enzyme in saliva
• What is the role of the liver?


  Where bile is produced
• What is the role of the gallbladder?


  Where bile is stored
• What is the role of the large intestine?


  Where excess water is absorbed from food
• What is the role of the rectum?


  Where the feces are stored before they are released through the anus
• What is the role of the small intestine?


  • Bile is released from gallbladder into small intestine

  • Enzymes: protease amylase and lipase complete digestion

  • Digested food is absorbed into blood
• What is the role of the pancreas?


  • Produces enzymes: protease amylase lipase and insulin

  • Releases protease amylase lipase into small intestine
• What is the role of the stomach? 


  • Pummels the food with its muscular walls

  • Produces the protease enzyme - pepsin

  • Produces hydrochloric acid

  -> to kill bacteria

  -> give the right pH for the pepsin to work (pH - 2)
• How do you prepare a food sample?

  1. Get a piece of food and break it up using a pestle and mortar
  2. Transfer the ground up food to a beaker and add some distilled water
  3. Give the mixture a good stir with a glass rod to dissolve some of the food
  4. Filter the solution using a funnel-lined with filter paper to get rid of the solid bits of food
• How do you test for sugar?

  1. Prepare a food sample and transfer 5cm³ to test tube
  2. Prepare a water path so it is set to 75°
  3. Add some Benedict solution to a test tube (about 10 drops) using a pipette
  4. Place the test tube in the water bath leave it for five minutes
  5. If the food sample contains sugar the solution will change from blue to green yellow or brick red– depending on how much sugar is in the food
• How do you test for starch?

  1. Prepare a food sample and transfer 5cm³ of your sample to a test tube
  2. Then add a few drops of iodine solution and gently shake the tube to mix contents
  3. If the sample contains starch the color of the solution will change from browny-orange to black or black-blue
• How do you test for protein?

  1. Prepare a sample of your food then transfer 2cm³ of your sample to a test tube
  2. Add 2cm³ Biuret solution to the sample and mix the contents by gently shaking
  3. If the food sample contains protein the solution will change from blue to purple
• How do you test for lipids( oils and fats)?

  1. Prepare a sample of food (but you don't need to filter it) transfer about 5cm³ into test tube
  2. Use pipette and add 3 drops of Sudan III stain solution and shake gently
  3. If sample contains lipids it will seperate and the top layer with be red
• What is the pathway of oxygen?


  mouth/nose -> trachea -> bronchus -> bronchiole -> alveoli
• What is the pathway of blood?


  vena cava -> right atrium -> valve -> right ventricle -> valve -> pulmonary artery -> pulmonary vein -> left atrium -> valve -> left ventricle -> valve -> aorta
• How and where is heart rate controlled?


  Group of cells called pacemaker in the right atrium wall
• How does the pacemaker control the heart rate?


  Produce a small electric impulse which spreads just surrounding muscle cells causing them to contract
• What do white blood cells do?


  • Phagocytosis

  -> engulf pathogens

  • Antibodies

  -> use to fight micro-organisms

  • Antitoxins

  -> neutralise any toxins produced by micro-organisms
• What do platelets do and what happens when you don't have enough?


  • help blood clot in wound - stop blood pouring out and micro-organisms getting in

  • a lack of platelets causes excessive bleeding and bruising
• What is plasma?


  A pale straw coloured liquid which carries everything
• What does plasma carry?


  • Red/white blood cells

  • Platelets

  • glucose, amino acids and protein

  • carbon dioxide from lungs

  • urea from liver to kidneys

  • hormones

  • antibodies and antitoxins produced by white blood cells
• How can coronary heart disease cause heart attacks?

  1. Conanary arteries (supply blood to muscles of heart) get blocked by layers of fatty material building up
  2. Arteries become narrow so blood flow is restricted and there is a lack of oxygen to heart muscles causing a heart attack
•  What is cholesterol?


  An essential lipid that your body produces and needs to function properly, too much of a certain type of cholesterol (LDL cholesterol) can cause health problems
• How can having a high cholesterol cause coronary heart disease?


  LDL cholesterol in the bloodstream can cause fatty deposits to form inside arteries
• How does stents reduce risk of coronary heart disease?


  Stent pushes on artery wall squishing the fatty deposit which slows down the rate of fatty deposits building up
•  What are the two types of tumour cells?


  • benign

  • maligant
• What is a benign tumour cell?


  Tumor cells grow until there's no more room, tumour stays in one place rather than invading other tissues in the body - non cancerous