bioenergetics

• photosynthesis

  • takes place in chloroplasts in green plant cells - contain chlorophyl which absorb light
  • energy is transferred to chloroplasts from environment by light
  • photosynthesis is endothermic - energy transferred from environments
  • carbon dioxide + water = glucose +oxygen
• respiration

  • transfers energy from glucose to convert the rest of glucose into other useful substances
  • cellulose - strong plant cells
  • amnio acids - glucose combined with nitrate ions making amino acids = proteins
  • stored as oils or fats - storing in seeds
  • stored as starch - stored in roots ready when photosynthesis isnt occurring is insoluble
• rate of photosynthesis

  • light intensity
  • concentration of co2
  • temperature
  • amount of chlorophyll
• photosynthesis practical

  • rate at which pondweed produces oxygen = photosynthesis rate
  • source of light placed at specific distance
  • pondweed left to photosynthesis for set time - oxygen collected in capillary tubes
  • syringe used to draw gas bubble in tube and measured
  • temperature and time = control
  • repeated twice with light source varying distances
  • independent = distance light is away
  • dependent = oxygen produced
  • $light intensity =$$1/distance^2$
• greenhouses

  • trap suns heat
  • light is needed for photosynthesis , supply of artificial light
  • increase carbon dioxide and temperature with parafin heaters
  • keeping plants enclosed keep them free of pests
• respiration

  • process of transferring energy from glucose which goes in every cell
  • build up larger molecules to smaller ones
  • muscles to contract
  • allows to regulate body temperature
• metabolism

  • all the chemical reactions in an organism
  • small glucose molecules joined to form starch , glycogen and cellulose
  • lipid molecules made of one molecule of glycerol and three fatty acids
  • glucose combined with nitrate ions = amino acids
  • glucose broken down
  • excess protein broken down to produce urea
• aerobic respiration

  • happer in mitochondria
  • glucose+oxygen=carbon dioxide+water
• anaerobic respiration

  • does not transfer as much energy
  • glucose=lactic acid
  • in yeast cells is called fermentation
  • glucose=ethanol+carbon dioxide
• exercise

  • oxygen debt is amount of extra oxygen your body needs to react with build up of lactic acid
  • oxygen reacts with lactic acid to from cos and water