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• What is the word equation for photosynthesis?

  Carbon dioxide + water -> glucose + oxygen
• How do plants use glucose?

  - Respiration

  - Making cellulose

  - Making amino acids

  - Stored as oils or fats

  - Stored as starch
• What factors can limit the rate of photosynthesis?

  - Intensity of light

  - Concentration of CO2

  - Temperature

  - Chlorophyll
• How does light intensity affect the rate of photosynthesis?

  As the light level is raised, the rate of photosynthesis increases steadily, but only up to a certain point
• How does carbon dioxide affect the rate of photosynthesis?

  Increases the rate up until a certain point up until the graph flattens our
• How does temperature affect the rate of photosynthesis?

  Temperature is too low- Enzymes needed for photosynthesis work too slow

  Temperature is too high- enzymes are damaged and denature
• Graph of light intensity and temperature?

  
• Graph of light intensity and Co2 concentration?

  
• PRACTICAL:

  Measure rate of photosynthesise using oxygen production?

  1) Source of white light is placed at a specific distance from the pondweed

  2) Pondweed left to photosynthesise for some time

  3) Count the bubbles that are seen when the plant is photosynthesising

  Control = Temperature, time pondweed is left to photosynthesise

  Depedent= Oxygen production

  Independent= distance away from light source
• What is the inverse square law?

  Light intensity = 1 ÷ (d)^2

  
• How to artificially create the ideal conditions of farming?

  - Greenhouses

  - Help to trap the sun's heat

  - Make sure that temperature isn't a limiting factor

  - Costs a lot of money
• What is respiration?


  The process of transferring energy from glucose, which goes on in every cell
• What can the energy from respiration be used for?

  - Build up larger molecules from smaller ones

  - Used to allow muscles to contract

  - Energy used to keep body temperature steady
• What is metabolism?

  The sum of all chemical reactions in an organism
• What is aerobic respiration?

  Glucose reacts with oxygen to release oxygen
• Equation for aerobic respiration

  glucose + oxygen → carbon dioxide + water + energy

  
• What is anaerobic respiration?

  Glucose is broken down to release energy without oxygen
• Equation for anaerobic respiration?

  glucose --> lactic acid + energy

  
• Why is anaerobic respiration less efficient than aerobic respiration?

  - Transfers energy less

  - Glucose isn't fully oxidised
• What is oxygen debt?

  The amount of oxygen needed to convert lactic acid into glucose after anaerobic respiration
• Why can anaerobic respiration lead to muscle fatigue?

  A build up of lactic acid in muscles prevents efficient muscle contraction
• What is fermentation?

  anaerobic respiration
• What is the equation for fermentation?

  Glucose --> ethanol + carbon dioxide
• What is fermentation used for?

  To make bread and alcoholic drinks
• What happens when you exercise?

  - Respire more

  - Breathing rate and breath volume increases

  - Vigorous exercise can lead to anaerobic respiration

  -Long periods of exercise can cause muscle fatigue
• What happens when you respire anaerobically?

  Oxygen debt:

  - Have to repay the oxygen you didn't get to your muscles in time

  - Breathing hard for a while after you stop exercising to get more oxygen into your system

  - Pulse and breathing are also staying high while there are high levels of lactic acid and CO2

  -Oxygen forms with the lactic acid to form CO2 and water
• How could you investgate the effect of exercise on the body?

  1) Measure breathing rate by counting breaths and heart rate by taking pulse

  2) could take pulse after sitting down or jogging for 5 minutes

  3) Pulse rate will increase the more intense the exercise is, as your body needs more oxygen in the muscles and to take more carbon dioxide away from the muscles

  4) To reduce the effect of any random errors on your results, do it as a group and plot the average pulse rate for each exercise