Bioenergetics - T4

• photosynthesis equation

  water + carbon dioxide ------> glucose + oxygen

  6CO2 + 6H2O ------> C6H12O6 + 6O2
• is photosynthesis exo or endothermic

  endothermic (takes in light energy)
• what four factors affect the rate of photosynthesis

  -CO2 concentration

  -light intensity

  -temperature

  -chlorophyll concentration
• graph of how co2 conc affects photosynthesis


  levels off when there is another limiting factor

  
• graph of how light intensity affects rate of photosynthesis


  levels off when there is another limiting factor

  
• graph of how temperature affects rate of photosynthesis


  increases until optimum temp

  enzymes denature so no photosynthesis

  
• what is the inverse square law


  the light intensity is inversely proportional to the square of the distance from the source

  
  

  light intensity = 1/distance^2

  
• what are these factors important in

  enhancing greenhouse conditions to gain max rate while still maintaining profit
• uses of glucose from photosynthesis:

  - used for respiration

  - converted into insoluble starch for storage

  - used to produce lipids for storage

  - used to produce cellulose, which strengthens the cell wall

  - used to produce amino acids for protein synthesis

  - to produce proteins, plants also use nitrate ions that are absorbed from the soil
• respiration


  continually occurring exothermic reaction that supplies the energy for all living processes
• aerobic respiration

  glucose +oxygen-> carbon dioxide + water
• anaerobic respiration

  glucose -> lactic acid

  
  

  LESS ENERGY due to the incomplete oxidation of glucose
• plant / yeast respiration

  glucose -> ethanol + carbon dioxide

  
  

  fermentation

  -> economic importance in manufacture of bread and alcohol
• what is respiration needed for

  movement

  warmth

  chemical reactions to build larger molecules
• what does exercise cause

  inc HR, BR, breathing volume

  -> supply more oxygenated blood

  
  

  if insufficient, anaerobic respiration will take place
• effects of anaerobic respiration

  long period of vigorous activity cause muscles to fatigue and stop contracting effectively

  -> lactic acid build up causes O2 debt
• what is oxygen debt


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

  blood transports from muscles to liver, where it is converted to glucose
• what is metabolism

  sum of all chemical reactions in the body-> energy from respiration used for the continual enzyme controlled processes of metabolism that synthesise new molecules
• metabolism reactions includes:

  - glucose into starch, glycogen or cellulose

  - formation of lipids from fatty acids and glycerol

  -formation of amino acids from glucose and nitrate ions

  -respiration

  -breakdown of excess proteins into urea