Topic 5

• What are the two stages of photosynthesis?

  Light-dependent reaction and light-independent reaction
• Where do the light-dependent reactions occur in a plant cell?

  On the thylakoid membranes or grana
• What is the purpose of the light-dependent reaction?

  To create ATP and reduced NADP
• What is the fluid center of the chloroplast called?

  Stroma
• What is chlorophyll a's color?

  Blue/green

  
• Why do leaves appear green?

  Because 500-550nm wavelengths are reflected
• What are the five key pigments in chlorophyll and their colors?

  1. Chlorophyll a - blue/green
  2. Chlorophyll b - yellow/green
  3. Carotene - orange
  4. Xanthophyll - yellow
  5. Phaeophytin - grey
• What happens during photoionisation of chlorophyll?

  Electrons become excited and leave chlorophyll
• What is photolysis?

  Splitting of water into oxygen, H+, and e-
• What is the equation for photolysis of water?

  $H_2O \rightarrow \frac{1}{2} O_2 +$$2e^- +$$2H^+$
• What is the role of NADP in photosynthesis?

  To form reduced NADP by picking up H+
• What is chemiosmosis in the context of photosynthesis?

  Protons move through ATP synthase to produce ATP

  
• What are the steps of chemiosmosis in photosynthesis?

  1. Electrons move along electron-carrier proteins
  2. Energy from electrons pumps protons across membranes
  3. An electrochemical gradient is created
  4. Protons pass through ATP synthase, producing ATP
  5. Protons combine with NADP to form reduced NADP

  
• What is the Calvin cycle also known as?

  The light-independent reaction
• What does the Calvin cycle use to form a hexose sugar?

  Carbon dioxide, reduced NADP, and ATP
• What enzyme catalyzes the reaction in the Calvin cycle?

  Rubisco
• What is the product of the Calvin cycle?

  Hexose sugar
• What happens to some carbon from triose phosphate (TP) in the Calvin cycle?

  It is converted into useful organic substances
• What is the role of RuBP in the Calvin cycle?

  To regenerate for the continuity of the cycle
• What are limiting factors in photosynthesis?

  Factors that reduce the rate of photosynthesis

  
• What are common techniques to remove limiting factors in agriculture?

  1. Artificial lighting to maximize light intensity
  2. Heating greenhouses to increase temperature
  3. Burning fuel to release more carbon dioxide
• What is the relationship between photosynthesis and plant growth?

  Maximizing photosynthesis promotes plant growth
• What is substrate-level phosphorylation?

  Adding phosphate groups to glucose from ATP
• Where does glycolysis occur?

  In the cytoplasm
• What are the three key stages of glycolysis?

  1. Phosphorylation of glucose
  2. Splitting of glucose into TP
  3. Oxidation of TP to form pyruvate

  
• What is the net amount of ATP produced from glycolysis?

  2 ATP

  
• What happens to pyruvate after glycolysis?

  It is oxidised to acetate

  
• What is produced during the link reaction?

  2 x Acetyl CoA, 2 x CO2, 2 x reduced NAD
• What does the Krebs cycle generate?

  8 reduced coenzymes, 2 ATP, and 4 CO2

  
• What is the role of the electron transport chain in respiration?

  To pass electrons and pump protons

  
• What does the electrochemical gradient do in respiration?

  It drives protons back into the matrix
• What is produced when protons move through ATP synthase?


  ATP
• What is the relationship between respiration and metabolism?

  Respiration produces ATP needed for metabolism
• What factors affect respiration?

  Temperature and pH changes
• What are the key terms related to photosynthesis and respiration?

  • Chloroplast
  • Thylakoid membrane
  • Grana
  • Light-dependent reaction
  • Light-independent reaction
  • Pigment
  • Stroma
  • Rubisco
  • Electrochemical gradient
  • Substrate-level phosphorylation
• What is the role of pyruvate in aerobic respiration?

  It is needed for subsequent stages.
• Where does the conversion of pyruvate into acetyl CoA occur?

  In the mitochondrial matrix.

  
• What accumulates in the mitochondrial matrix during aerobic respiration?

  Reduced coenzymes.
• What do reduced coenzymes release in the mitochondrial matrix?

  Protons (H+) and electrons (e-).
• How do electrons move through the electron transport chain?

  They lose energy as they move.