bionergectics

    Cards (43)

    • Photosynthesis
      1. Takes place in the leaves
      2. Takes place in chloroplasts
      3. Chlorophyll absorbs light energy
      4. Converts carbon dioxide and water into glucose and oxygen
    • Photosynthesis is an endothermic reaction, where energy is transferred from the environment to chloroplasts by light
    • Carbon dioxide and water supply for photosynthesis
      1. Carbon dioxide diffuses into leaves through stomata
      2. Water is taken up from soil by roots and transported to leaves via xylem
    • Products of photosynthesis
      • Glucose is the main product
      • Oxygen is also produced but not as important
    • Uses of glucose produced by photosynthesis
      • Cellular respiration
      • Making cellulose
      • Making starch
      • Making amino acids
      • Making oils and fats
    • Plant growth rate is often dependent on the rate of photosynthesis
    • Factors affecting the rate of photosynthesis are light intensity, temperature, carbon dioxide concentration, and the amount of chlorophyll
    • Factors affecting photosynthesis
      • Light intensity
      • Temperature
      • Concentration of carbon dioxide in the air
      • Amount of chlorophyll that the plants have
    • Chlorophyll
      The pigment within chloroplasts that absorbs the light energy needed for photosynthesis
    • Plants have less chlorophyll
      They won't be able to carry out as much photosynthesis
    • Cellular respiration
      An exothermic reaction which transfers energy from glucose and is continuously occurring in living cells
    • Factors that can reduce chlorophyll levels
      • Disease (e.g. tobacco mosaic virus)
      • Environmental stress
      • Lack of nutrients (e.g. water)
    • Limiting factors for photosynthesis are normally light, carbon dioxide and temperature
    • Cellular respiration
      Breaking apart glucose molecules to release the energy that's trapped inside
    • Graphing limiting factors for photosynthesis
      1. Plot light intensity on x-axis
      2. Plot rate of photosynthesis on y-axis
    • How organisms use their energy
      • Building up larger molecules from smaller ones (e.g. combining amino acids to form proteins)
      • Muscular contraction for movement
      • Maintaining body temperature
    • Energy is needed for loads of reactions in our cells, most of which are catalyzed by enzymes
    • As light intensity increases
      Rate of photosynthesis increases
    • The line flattens out when something else becomes the limiting factor, such as carbon dioxide concentrations or temperature
    • Metabolism
      All the chemical processes that occur within a living organism in order to maintain life
    • As carbon dioxide concentration increases
      Rate of photosynthesis increases
    • Aerobic respiration
      • More common type, takes place whenever there's enough oxygen, most efficient way to transfer energy from glucose, takes place continuously in both plants and animals, takes place within mitochondria
    • As temperature increases
      Rate of photosynthesis increases initially, then starts to drop as enzymes denature
    • Aerobic respiration
      Glucose + Oxygen -> Carbon dioxide + Water
    • Anything beyond 45 degrees, the enzymes are fully denatured and the rate of reaction falls to zero
    • Graphs can show multiple limiting factors, by comparing curves at different conditions
    • The equation for aerobic respiration is the opposite of the equation for photosynthesis
    • Farmers creating conditions to increase photosynthesis
      • Using greenhouses to trap heat and provide artificial light
      • Pumping in carbon dioxide
      • Using paraffin heaters for heat and CO2
      • Applying fertilizers for essential minerals
      • Using pesticides to control pests
    • Anaerobic respiration
      • Respiration without oxygen, used when there is not enough oxygen to keep up with the demands of aerobic respiration
    • Creating optimal conditions for photosynthesis can be costly for farmers, so they have to weigh the extra cost against the expected yield increase
    • Anaerobic respiration
      Glucose -> Lactic acid
    • Anaerobic respiration is less efficient because it involves incomplete breakdown of glucose and leads to lactic acid buildup
    • Anaerobic respiration in plants and yeast
      • Glucose is converted to ethanol and carbon dioxide instead of lactic acid
      • In yeast, this process is called fermentation and is used to make bread, beer, and wine
    • Exercise
      Causes the body to carry out more cellular respiration
    • Cellular respiration during exercise

      1. Muscles require more energy
      2. Muscles require more oxygen
      3. Breathing rate and volume increase
      4. Heart rate increases
    • Insufficient oxygen during intense exercise

      Cells use anaerobic respiration
    • Anaerobic respiration

      Less efficient than aerobic respiration, produces lactic acid
    • Lactic acid buildup during exercise
      Causes a burning sensation in muscles
    • Removing lactic acid after exercise

      1. Lactic acid carried to liver
      2. Lactic acid reacts with oxygen
      3. Lactic acid converted back to glucose
    • Oxygen debt

      Extra oxygen needed to remove lactic acid after exercise
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