Energy Transfers

• What is the equation for photosynthesis?

  6CO2 + 6H2O --> C6H12O6 + 6O2
• Define aerobic respiration


  respiration using oxygen
• Define anaerobic respiration


  respiration without oxygen
• What is the equation for respiration?


  C6H12O6 + 6O2 --> 6CO2 + 6H2O
• In animals, what does anaerobic respiration produce?


  lactate
• In plants, what does anaerobic respiration produce?


  ethanol + CO2
• What does ATP stand for?

  adenosine triphosphate
• What is ATP made from?


  adenine, ribose sugar and 3 phosphate groups
• How is ATP produced?


  ADP + inorganic phosphate using energy from an energy releasing reaction
• What enzyme catalyses the production of ATP?

  ATP synthase
• Define phosphorylation


  the addition of a phosphate group to a molecule
• How is energy released from ATP?


  it is hydrolysed into ADP + inorganic phosphate
• What catalyses the hydrolysis of ATP?


  ATP hydrolysis
• What 6 features of ATP make it adapted to storing energy?

  small, soluble, easily hydrolysed, can't pass through cell membranes, can cause phosphorylation, quickly regenerated
• What are thylakoids?


  fluid filled sacs found in the chloroplasts which contain chlorophyll a, chlorophyll b and carotene
• What is a photosystem?


  chlorophyll or carotene attached to its associated protein
• What are grana?

  stacks of thylakoids held together by lamella
• What are the 2 photosystems used to capture light energy?


  PS1 and PS2
• What wavelength does PS1 absorb best?

  700nm
• What wavelength does PS2 absorb best?

  680nm
• What is the stroma?

  substance within the chloroplasts inner membrane which contains enzymes, sugars and acids
• What are starch grains?

  stores of carbohydrates which do not need to be used immediately
• What is reduction?


  gaining of electrons
• What is oxidisation?


  the loss of electrons
• What is the coenzyme in photosynthesis?


  NADP
• What are the 2 stages of photosynthesis?


  light dependant and light independent
• Define photoionisation

  the excitation of chlorophyll, releasing electrons which are used to produce ATP, NADPH, and for photolysis
• What is another name for the light independent reaction?

  the Calvin cycle
• Where does the light dependant reaction occur?

  thylakoid membrane
• Where does the light independent reaction occur?

  stroma
• What is the energy from photoionisation used for?

  photophosphorylation to produce ATP, forming NADPH from NADP, and photolysis
• What are the two types of photophosphorylation?

  cyclic and non-cyclic
• When does photophosphorylation occur?


  during the light dependant reaction
• In non-cyclic photophosphorylation, what occurs during the photoionisation of chlorophyll?


  the excited electrons are released from chlorophyll in PS2 and move down the electron transport chain to PS1
• In non-cyclic photophosphorylation, what occurs during the photolysis of water?


  light energy hydrolyses water to produce protons, electrons and oxygen. these electrons replace those lost from PS2
• In non-cyclic photophosphorylation, what occurs for ATP to be produced?


  electrons lose energy as they travel down the transport chain, as the energy from it is used to transport protons into the thylakoid, creating a concentration gradient, and forcing protons to diffuse through ATP synthase into the stroma
• In non-cyclic photophosphorylation, what occurs for NADPH to be produced?


  electrons are excited in PS1, and these electrons are transferred to NADP to form NADPH
• Define chemiosmotic theory


  the process of electrons flowing down the electron transport chain to produce a proton gradient
• What occurs during the first stage of the Calvin Cycle?

  RuBP and CO2 produce GP, which is catalysed by rubisco
• RuBP


  ribulose biphosphate