bioenergetics

• what 3 factors affect photosynthesis?

  temperature, concentration or carbon dioxide, light intensity
• what happens to the rate of photosynthesis if temperature increases?


  the rate increases
• what happens to the rate of photosynthesis if the temperature goes above 45 degree celcius?

  rate drops to zero because the enzymes controlling photosynthesis have been destroyed
• what happens to the rate of photosynthesis if the concentration of carbon dioxide increases?


  the rate of photosynthesis increases
• after reaching a certain point, an increase in CO2 has what affect?

  no further affect, CO2 is no longer the limiting factor
• after reaching a certain point, any increase in light has what effect?

  no further affect, its no longer the limiting factor
• whats a limiting factor?

  a factor that prevents a reaction from going faster
• what happens to the rate of photosynthesis as light intensity increases?


  the rate of photosynthesis increases
• endothermic?

  reactions that take in heat/ require heat energy
• whats chlorophyll?

  the green pigment found in most plants, responsible for photosynthesis
• whats the word equation for photosynthesis?

  light

  carbon dioxide + water ---> glucose + oxygen

  chlorophyll
• whats the symbol equation for photosynthesis?

  6CO2 + 6H2O -> C6H12O6 + 6O2
• what is the inverse square law?

  when a light source is moved to double the distance then the light intensity reduces by a quarter
• how do we investigate photosynthesis? (require practical)

  investigating the effect of light intensity on the rate of photosynthesis using an aquatic organism such as pondweed
• method for investigating photosynthesis RP?

  method:

  1. place a piece of pondweed in a beaker and shine a light at it using a lamp a specific distance away
  2. record the number of bubbles of gas coming out of the pondweed in one minute
  3. repeat this with the lamp at different distances from the pondweed
• whats the independent variable in photosynthesis RP?

  the light intensity (distance from the light)
• whats the dependent variable (one we measure) in photosynthesis RP?

  number of bubbles in one minute
• whats the control variable (one we keep the same)

  piece of pondweed, temperature, concentration of carbon dioxide
• what happens to the heart rate, breathing rate and the breath volume during exercise?

  they all increase to supply the muscles with more oxygen and glucose for the increase in aerobic respiration
• what is aerobic respiration?

  respiration that uses oxygen to release energy from glucose
• what is anaerobic respiration?

  Respiration without oxygen, producing energy and lactic acid
• when is anaerobic respiration needed?

  during periods of vigorous activity, when the muscles aren't supplied with enough oxygen, so anaerobic respiration takes place in the muscle cells
• what is the word equation for normal respiration (aerobic respiration)?

  Glucose + Oxygen -> Carbon Dioxide + Water + Energy
• what is the symbol equation for normal respiration (aerobic respiration)?

  C6H12O6 + 6O2 -> 6CO2 + 6H2O
• whats the word equation for respiration without oxygen (anaerobic respiration) in animals?

  glucose -> lactic acid
• whats the word equation for anaerobic respiration in plants and yeast?

  Glucose → Ethanol + Carbon dioxide
• what type of chemical reaction is respiration?

  exothermic
• whats an exothermic reaction?

  reactions that release energy/ heat into the environment
• whats fermentation?

  the conversion of sugar to alcohol and carbon dioxide in yeast
• whats lactic acid?

  a compound produced when cells respire without oxygen
• whats oxygen debt?

  oxygen defficiency caused by anaerobic respiration during vigorous exercise
• whats a metabolism?

  the sum of all the chemical reactions occurring in the body
• where in the body is lactic acid broken down after exercise?

  the liver