Bioenergetics

• photosynthesis is an endothermic reaction
• during photosynthesis, energy is transferred from the enviroment to the chloroplasts
• factors that limit the rate of photosynthesis is:

  light intensity

  concentration of CO2

  temperature

  amount of chlorophyll
• glucose produced in photosynthesis is used for:

  • cellular respiration
  • converted into starch for long term storage
  • produce fats and oils for storage
  • produce amino acids for protein synthesis
  • glucose and nitrate ions from the soil is used to produce proteins
• aerobic respiration uses oxygen for respiration

  it transfers energy from glucose

  takes place in the mitochondria
• the equation for aerobic respiration is

  glucose + oxygen → water + carbon dioxide
• anaerobic respiration is used there is not enough oxygen to carry out aerobic respiration
• anaerobic respiration is used when not enough oxygen is being supplied to the muscles
• anaerobic respiration doesnt transfer as much energy as aerobic respiration because glucose isnt fully oxidised (it wont combine with oxygen)
• the equation for anaerobic respiration in animals is:

  glucose → lactic acid
• the equation for anaerobic respiration in plants and yeast is:

  glucose → ethanol + carbon dioxide
• fermentation is anaerobic respiration in yeast cells
• fermentation has a good economical impact as it manufactures bread and alcoholic drinks
• during exercise the human body reacts to increased demand for energy
• when you exercise you respire more
• during exercise the heart rate, breathing rate, and breath volume increases to supply the muscles with more oxygenated blood
• increased muscle activity causes lactic acid build up which can cause cramps
• incomplete oxidation of glucose causes the build up of lactic acid and oxygen debt
• oxygen debt occurs when there isn't enough oxygen available during intense exercise
• intense exercise can causes fatigued muscles that will contract less
• metabolism is the sum of all reactions in a cell/body