16. Photosynthesis

• Where does photosynthesis take part

  Chloroplast of cells in leaves
• What is oxidation

  Loss of electrons and hydrogen
• What is reduction

  Gain of electrons and hydrogen
• What happens during the light dependent reaction

  Photons of light are absorbed by the chlorophyll. This causes a pair of electrons to become excited and leave the chlorophyll. These electrons travel along the ECT through a series of redox reactions. These redox reactions release energy that are used to pump protons through the membrane, the protons, then pass through ATP synthase creating ATP.
• Where does the dependent reaction happen?

  Thylakoid membane
• What is photolysis

  A molecule of water is split into electrons and protons and oxygen
• Products of light dependent reaction?

  ATP, reduced nadp
• Where does the light independent reaction take place

  Storms of the chloroplast
• Describe the calvin cycle (LIR)

  Co2 combines with a 5C molecule called Ribulose biohosphate. This is catalysed by rubisco. Forms two glycerate 3 phosphate molecules (3C) this is then reduced to two molecules of triose phosphate

  1/6 becomes organic substances

  the other 5 regenerates RuBp
• Which reaction would be most affected by temperature

  Light independent- contains enzymes
• What are some factors limiting rate of photosynthesis

  Light - amount of photons

  water - photolysis

  temperature- kinetic energy
• What is the benefit to using commercial glasshouses

  farmers can achieve higher yields, and it allows crops to be grown out of season
• Why do commercial glasshouses increase crop yield?

  They control limiting factors
• How can light intensity, be controlled in a glasshouse?

  Artificial lighting
• How can carbon dioxide concentration be controlled in a glasshouse?

  Pump carbon dioxide through the glasshouse
• How can temperature be controlled in a glasshouse?

  Ventilation, shading, heating, and cooling systems.
• Why could high temperatures lower the rate of photosynthesis?

  High temperatures cause more water loss, excessive water loss can lead to plants closing their stomata so this means carbon dioxide would not be able to enter the leaves and rates of photosynthesis would drop