1. State the definition for Homeostasis
    Homeostasis is the maintaining of a Constant Internal Enviroment.
  2. What Temperature do Enzymes work best at in the body?
    a) 560
    b) 350
    • c)370
    • Explanation;
    • If our body temperature is too hot or too cold then our enzymes will begin to denature and our body will not be able to function properly.
  3. Name 4 things that need to be controlled in our bodies.
    • Body Temperature, Water Content, Ion Content and Blood Sugar Level.
    • Explanation;
    • Body Temperature- We cannot be too hot or too cold our body temperature must stay constant.
    • Water Content-Too much water could move in or out of our cells which would damage them which is why water content must stay constant.
    • Ion Content- Too much Ions could move in or out of cells causing damage to our cells.
  4. What part of the Brain controls our Body Temperature?
    • Thermoregulatory Centre
    • This is your own body thermosat. It contains Receptors that are sensitive to the temperature of the blood that is flowing through the Brain. The Thermoregulatory Centre also recives impulses from the skin regarding the skins temperature.
  5. How does your body respond when you are too hot?
    • Hairs lie flat.
    • Sweat Glands produce sweat which evaporates through the skin.
    • Blood Vessels supplying the skin moves closer to the surface of the skin which makes it easier for heat to be transferred from blood to outside enviroment.
  6. How does your body respond when you are too cold?
    • Hairs stand up to trap an insulating layer of air.
    • No sweat is produced
    • Blood Vessels close to skin surface are closed off.
    • You begin to shiver which generates energy as heat.
  7. Explain what an Enzyme is?
    • An Enzyme is a Biological Catalyst.
    • Enzymes are Proteins which are a chain of Amino Acids. These chains are are folded into unique Shapes which enzymes use for their unique jobs.
  8. What does Amylase Break down and what into?
    Amylase breaks down Starch into Maltose and other simple sugars eg Dextrins.
  9. Where do we find Amylase in the body?
    Salivary Glands, Pancreas and Small Intestine.
  10. What does Protease break down and what into?
    Protease breaks down Proteins into Amino Acids.
  11. Where is Protease found in the body?
    Stomach, Pancreas and the Small Intestine.
  12. What does Lipase break down and what into?
    Lipase breaks down Fats into Glycerol and Fatty Acids.
  13. What is a Limiting Factor?
    A Limiting Factor is something that is preventing Photosynthesis from taking place any faster.
  14. What is the obvious limiting factor at night?
    • Light Intensity.
    • Explanation; Because light provides the Energy needed for Photosynthesis to take place, so it affects the RATE OF PHOTOSYNTHESIS. As light intesity increases so does the Rate of Photosynthesis but only to a certain point where there is another limiting factor that isnt light intensity.
  15. What is the obvious limiting factor in the winter?
    • Temperature.
    • Explanation; If the temperature is too low or too high then the Enzymes in the plants begin to denature and not work resulting in the plant being damaged.
  16. What is Diffusion?
    • Diffusion is the passive movement of particles from an area of HIGH CONCENTRATION to an area that is a LOW CONCENTRATION.
    • Diffusion happens in both liquids and gases because the particles are able to move freely.
  17. What is Osmosis?
    Osmosis is the movement of water molecules across a partially permamble membrane from a region of a high water concentraion to a region of low water concentration.
  18. What does Photosynthesis produce?
    Photosynthesis produces food for the plant. To do this it needs light, water and Carbon Dioxide.
  19. What does Chlorophyll absorb?
    • Chlorophyll absorbs Light Energy from the sun.
    • Explanation; This light energy is then used to convert CO2 and Water into the sugar GLUCOSE.
  20. How does CO2 from the air enter the plant?
    CO2 enters the plant through small holes at the bottom of the leaf called STOMATA.
  21. Explain how Water from the Soil gets to the leaves? (3)
    It enters from the soil through the roots, then travels up the stem through tubes called the XYLEM and into the leaves.
  22. Where does CO2 and Water come together to make Glucose through PHOTOSYNTHESIS?
    Palisade Cells.
  23. Is Oxygen a waste product of Photosynthesis for the plant?
    yes and it leaves the plant back through the STOMATA
  24. What do Enzymes (biological Catalysts) reduce in a reaction?
    Active Energy.
  25. Explain how enzymes work?
    • Enzymes have a active site.
    • This active site is a special shape which fits with a substrate.
    • when an enzyme and substrate collide an enzyme-substrate complex forms, where the substrate binds with the Enzymes Active Site.
  26. Explain why increasing the temperature make Enzymes work faster to a certain point.
    As the temperature increases, the rate of enzyme action increases because the molecules have more kinetic energy and therefore move around more. This results in more collisions between enzymes and substrates and therefore more enzyme-substrate complexs are formed. However they only increase to a certain point and then begin to denature.
  27. What is the Optimum Temperature?
    the Optimum Temperature is the temperature that enzymes work best at.
  28. Why do enzymes DENATURE?
    The bonds that hold together the active site break which changes the shape of the enzyme. The substrate will then no longer fit into the Active site and therefore no enzyme-substrate complexes are formed. so the reaction can no longer take place.
  29. What is Mitosis?
    Mitosis is cell division for Growth and Repair.
  30. How many cells are formed from Mitosis?
    Two Cells are formed from Mitosis.
  31. Name the 5 Stages of Mitosis.
    • 1)Parent Cell.
    • 2)Chromosomes make identical copies of themselves.
    • 3)They line up along the centre.
    • 4)They move apart(split)
    • 5)Two daughter cells produced with identical chromosomes to the 1 parent cell.
  32. What happens if we have too much water or ion content in our bodies?
    Too much moves in and out of cells and damage them.
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