bio

• three differences between eukaryotic and prokaryotic cells?

  prokaryotic are smaller, eukaryotic are bigger. Prokaryotes don’t have a nucleus, prokaryotes don’t have mitochondria
• Human lungs


  • Provide a large(r) surface area
  • Capillaries are thin or alveoli / capillary walls are thin or one cell thick
  • Capillaries are close to the alveoli
  • Breathing (mechanism) moves air in and out or lungs are ventilated
  • Large capillary network (around alveoli) or good blood supply
• Gas exchange in human lungs

  1. Bring in (fresh) oxygen

  2. Remove carbon dioxide

  3. Maintain a concentration / diffusion gradient
• Many alveoli in human lungs
• Alveoli


  Provide a large(r) surface area
• Thin capillaries or alveoli / capillary walls

  Provide a short diffusion path (for oxygen / carbon dioxide)
• Breathing mechanism moves air in and out or lungs are ventilated
• Large capillary network (around alveoli) or good blood supply
• Large capillary network or good blood supply

  Removes oxygen(ated blood) quickly and brings carbon dioxide to the lungs quickly to maintain a concentration / diffusion gradient
• describe each stage of the cell cycle?

  DNA replicates and do other sub cellular structures such as the mitochondria/ribosomes. One set of chromosomes is pulled to each end of the cell the cytoplasm and cell membrane divides
• explain the lock and key theory?

  each enzyme has an active site, which is complementary to a substrate. So the substrate is broken down so products are released
• why does raft enzyme only act on a specific type of molecule?

  the active site has one specific shape
• what do you need to remember to do when using benedict’s solution?

  use a water bath to heat the solution after mixing it
• what are the colours for each of the different food tests?

  Iodine test: orange ->Blue-black Benedict's test: green -> yellow -> brick red Biuret test: blue -> lilac Sudan III test: no stain -> Red stain-orange
• what does the plant with excess glucose ss s result of photosynthesis?

  convert it into starch
• what happens to starch when there isn’t enough glucose from photosynthesis?

  it’s converted back into glucose so it can release energy
• what are some ways to develop an experiment?


  use different species, find a mean, test other factors
• how does not having enough sunlight cause yellow leaves and stunted growth?

  chlorophyll breaks down so there’s not enough glucose to make proteins for growth (via photosynthesis)
• what are magnesium ions used for in a plant?

  to make chlorophyll in their leaves
• what does TMV do to a plant?

  stunts growth as the leaves turn yellow meaning that there’s less photosynthesis causing there not to be enough glucose to make proteins for growth
• bacteria live on nodules (part of a living root tissue). these bacteria convert nitrogen gas into soluble nitrate ions. how do nodules benefit bacteria?

  they can obtain glucose from the plant for respiration
• what are nitrate ions used for in a plant?

  to create amino acids which are needed for the growth of a plant
• what are some control factors scientists can use in analysis?


  height, race, ethnicity, gender, BMI, age
• what makes data valid?

  long term, large amount of people
• what can make data invalid?

  people lie about there results, people change , short survey , small amount of people
• what are the effects of liver failure?

  no bile made - fats aren’t emulsified, pH of small intestine is not alkaline , enzymes in small intestine will not work effectively so they may lose weight. Lactic acid not broken down -> lactic acid builds up and it’s toxic so oxygen debt is higher meaning muscle pain. Glycogen stores not formed -> so cannot control blood glucose so diabetes may occur. Proteins aren’t broken down -> amino acids aren’t deaminated so ammonia isnt made and taken away however ammonia is toxic so it will build up in the blood.
• how do monoclonal antibodies work?

  they bind to the pathogen you’re looking for and afterwards then can show up using fluorescent dye to stain the bound mAbs
• what does a patient having increased phagoctosis do?

  the patient can engulf more pathogens therefore there’s less damage to the cells
• clinical trials how do they work?

  given first to healthy volunteers at a very low dose to see side effects. Then tested on some patients with the disease to check for the optimum dose, this can be done in a double blind trial where neither doctor or patient knows which drug is real to avoid biased results. can also do this to see if the drug actually works
• why are human mAbs probably better to use than mouse ones?

  less chance of rejection