1. What are the risk factors associated with heart disease
    • Smoking
    • High salt intake
    • High cholesterol
    • High blood pressure
    • Lack of exercise
    • Heredity 
    • Gender
    • Age
  2. Why do areas of the heart muscle die during a myocardial infarction?
    • Reduced blood flow in coronary artery, blocked
    • Less O₂ supplied
    • Respiration drops so cells die
  3. How are bacteria destroyed by phagocytes?
    • Phagocyte engulfs bacteria to form phagosome
    • Lysosomes fuse to it, emptying contens
    • Release enzymes, that hydrolyse bacteria
  4. What possible features could bacteria have that are never present in white blood cells?
    • Cell wall
    • Capsule
    • Circular DNA
    • DNA without histones
    • Flagellum
    • Plasmid
    • Pilus
    • 70S ribosomes (smaller)
    • Mesosome
  5. What are the adaptations of epithelial cells for absorption?
    • Microvilli -> increase SA
    • Mitochondria -> supply ATP for co-transport
    • Vesicles -> to bring carrier proteins to membrane
  6. How does absorption of glucose into the epithelial cell lead to water moving into cell?
    • Lowers Ψ
    • Gradient created
    • Water moves into cell by osmosis
  7. Why does the thickness of the ventricular walls increase during systole?
    • They are contracting
    • Causes an increase in ventricular pressure
  8. Why does blood flow in the aorta increase when ventricular pressure in the heart increases?
    • Ventricle pressure rises, blood starts to flow into aorta
    • Pressure above that in aorta causes AV to open
  9. How do you calculate heart rate?
    Exam qu: A dog's blood flow in the aorta rises 4 times in 2 seconds. What is the dog's HR?
    • Calculate beats per second (beats/sec)
    • Multiply by 60

    • 4beats ÷ 2sec = 2beats/sec
    • 2 × 60 = 120BPM
  10. Why does maltase only break down maltose (into glucose)?
    • Tertiary structure
    • Means that the active site complementary to maltose
    • By induced fit
    • Enzyme is a catalyst
    • Lowers activation energy
    • By forming an E-S complex
  11. Describe non-competitive inhibition of an enzyme.
    • Non-comp inhib binds to allosteric site on enzyme
    • Changes shape of active site
    • Substrate no longer complementary so E-S complex cannot form
    • Cannot be overcome by more substrate
  12. Describe competitive inhibition of an enzyme.
    • Comp inhib has similar shape to substrate
    • Competes for the active site
    • Can be overcome by more
    • substrate
Card Set
Biology and disease past paper questions.