bioenergetics (4)

• what is photosynthesis

  the process by which plants make glucose from sunlight. it is an endothermic reaction.
• word equation for photosynthesis

  carbon dioxide + water --> glucose + oxygen
• Symbol equation for photosynthesis

  co2 +h2o --> o2 + c6h12o6
• factors that affect the rate of photosynthesis

  temperature, light intensity, carbon dioxide concentration , amount of chlorophyll
• how does temperature affect the rate of photosynthesis

  as the temperature increases the rate of photosynthesis increases due to the control of enzymes , this increase continues until the optimum temperature for the enzymes is reached then anything after this causes the enzymes to denature and the reaction to slow down.
• how does light intensity affect the rate of photosynthesis

  higher the light intensity, faster the rate of reaction
• how does the concentration of carbon dioxide affect the rate of photosynthesis

  as concentration of carbon dioxide increases so does the rate of photosynthesis
• how does the amount of chlorophyll affect the rate of photosynthesis

  as the amount of chlorophyll increases so does the rate of photosynthesis
• practical for measuring the rate of photosynthesis

  measuring the oxygen production of a plant
• method for photosynthesis practical


  Put your 10 cm piece of pond weed into a beaker of water. Cover the pondweed with an inverted filter funnel. Fill the measuring cylinder with water. Use the ruler to position the beaker of pondweed 1 metre away from the light source. Start the stop watch and: a.count and record the number of bubbles released in three minutes b. record the volume of gas produced and collected in the measuring cylinder in the same three minutes.
• limiting factor

  a condition, that when in shortage, slows down the rate of a reaction.
• how can farmers use limiting factors to their advantage

  enhance the conditions of the greenhouse for a greater rate of photosynthesis. increasing growths and therefore profits
• inverse proportion


  when one factor increases whilst the other decreases
• inverse square law

  light intensity (fish symbol) 1 / distance ^2
• uses of glucose from photosynthesis (x5)


  respiration, converted into insoluble starch for storage, produce fat , produce cellulose to strengthen walls , combine with nitrates to form amino acids which produce proteins.
• is respiration exo or endothermic


  exothermic
• word equation for aerobic respiration


  glucose + oxygen --> carbon dioxide + water
• word equation for anaerobic respiration in animals 


  glucose --> lactic acid
• word equation for anaerobic respiration in plant and yeast cells (fermentation)


  glucose --> ethanol + carbon dioxide
• what can fermentation be used to make 


  bread and alcoholic drinks
• bodys responses to exercise

  heart rate , breathing rate and breath volume all increase
• oxygen debt

  the amount of extra oxygen the body needs after exercise to react with the accumulated lactic acid and remove it from cells
• metabolism definition


  the sum of all the reactions in a cell or the body
• examples of metabolic reactions (x5)


  glucose molecules being converted to starch, glycogen and cellulose by being joined together, a glycerol molecule and 3 fatty acids forming a lipid molecule , glucose and nitrate ions forming amino acids, the reactions in respiration , urea forming the breakdown of protein