Biogenetics

• Photosynthesis equation

  Carbon dioxide + water ——-> glucose + oxygen
• photosynthesis is an endothermic reaction as it takes in energy from the environment to the chloroplast by light
• Effect of temp on photosynthesis

  
  

  The temp needs to be just right, as if the temperature is too low. The enzymes needed for photosynthesis will work more slower. But if the plant is too hot the enzymes needed for photosynthesis & other reactions will become damaged. This happens at 45°.
• Effect of light intensity on photosyn

  
  

  As the light intensity increases the rate of photosynthesis also increases steadily. up to a certain point as light intensity increases, the rate of reaction does not ( when reached this point) as other limiting factors e.g temperature & carbon dioxide have occurred
• effect of carbon dioxide on photosy

  
  

  As CO2 increases, photosynthesis also increases up to a certain point past this point if CO2 increases the rate of photosynthesis doesn’t showing that CO2 is no longer a limiting factor
• Limiting factor - stopping photosynthesis from happening any faster
• effect of chlorophyll on photosythes

  
  

  The amount of chlorophyll can be affected in a plant by disease or environmental stress. these causes chlorophyll to become damaged or not make enough chlorophyll. This means that photosynthesis is reduced as not much light is absorbed.
• Use of inverse proportional - the inverse square law on light intensity in photosynthesis

  Inverse proportional describes the relationship between two factors, one in which increases & one in which decreases. The light source & plant increase the light intensity decreases. The light intensity is inversely proportional to the square of the distance.
• Farmers can use their knowledge of limiting factors to enhance the conditions in the greenhouse for a greater rate of photosynthesis. This will increase growth leading to increase profits.
• Photosynthesis, practical

  • Have a flask in which has sodium hydrogen carbonate
  • In the flask, add pondweed
  • place a white light, 10 cm away from the flask
  • Leave to photosynthesise
  • Then start a stopwatch
  • In one minute measure the amount of bubbles
  • Repeat two more times
  • Then measure the mean amount of bubbles
• Photosynthesis, practical, repeat, practical, changing the distance of the lamp to 20 cm, 30 cm & so on
• Respiration - the process of transferring energy from glucose in which goes on in every cell
• Respiration is an exothermic (given out)reaction which is continuously occurring in living organisms
• Aerobically (using oxygen)

  • uses glucose
  • Produces carbon dioxide & water
  • exo reaction
  • Transfers, large amounts of energy
• Anaerobically (without oxygen)

  • uses glucose
  • produces lactic acid
  • exo reaction
  • transfer & releases smaller amounts of energy than aerobic
• Anaerobic respiration is called for fermentation & has an economic impact on the manufacturers of bread & alcohol drinks
• Metabolism - all the chemical reactions that take place in a cell or in the body
• Metabolism includes

  Glucose - in which is converted into glycerol, starch & cellulose
• Metabolism includes

  Lipids - made from glycerol molecules & three fatty acids
• Metabolism includes

  Urea - made from the breakdown of excess protein
• Metabolism Includes

  Respiration - releasing energy from glucose
• Metabolism includes

  Proteins - which are made from amino acids which can be made from glucose & nitrate ions in plants