Topic 5

• Where does the light-dependent reaction occur?

  Thylakoid membranes of chloroplast
• Where does the light-independent reaction take place?

  Stroma of chloroplast
• What is the structure of thylakoid membranes?

  • Folded membranes
  • Contain photosynthetic proteins (chlorophyll)
  • Embedded with transmembrane electron carrier proteins
• What is chlorophyll's role in photosynthesis?

  Absorbs light in thylakoid membranes
• How do different pigments affect leaf color?

  Different proportions lead to different colors
• What is the advantage of having many pigments?

  Maximizes spectrum of visible light absorbed
• What is the first stage of photosynthesis?

  Light-dependent reaction in thylakoid membranes
• What does photolysis produce?

  Oxygen, H+, and electrons
• What happens during photoionisation of chlorophyll?

  Electrons are excited to a higher energy level
• What is chemiosmosis in photosynthesis?

  Protons move back across thylakoid membrane
• What is the role of ATP synthase in photosynthesis?

  Produces ATP from proton movement
• What are the products of the light-dependent reaction?

  ATP, reduced NADP, and oxygen
• What occurs in the Calvin cycle of the light-independent reaction?

  • Uses CO2, reduced NADP, and ATP
  • Forms hexose sugar
  • Occurs in stroma with Rubisco enzyme
• What is RuBP?

  5-carbon molecule in Calvin cycle
• What is GP?

  Glycerate-3-phosphate, a 3-carbon molecule
• What happens to GP in the Calvin cycle?

  It is reduced to form triose phosphate
• How is glucose produced in the light-independent reaction?

  Through multiple cycles of the Calvin cycle
• What are limiting factors of photosynthesis?

  Light intensity, CO2 concentration, temperature

  
• How does light intensity limit photosynthesis?

  Reduces ATP and reduced NADP levels

  
• How does temperature limit photosynthesis?

  Enzyme denaturation affects reaction rates

  
• How does CO2 concentration limit photosynthesis?

  Less CO2 reduces GP formation

  
• What agricultural practices maximize plant growth?

  • Artificial lighting to increase light intensity
  • Heating in greenhouses to raise temperature
  • Burning fuel to release CO2
• What is the benefit of agricultural practices for plant growth?

  Higher yields lead to more profit
• What are the stages of aerobic respiration?

  Glycolysis, Link reaction, Krebs cycle, Oxidative phosphorylation
• Where does glycolysis occur?

  Cytoplasm
• What is substrate-level phosphorylation in glycolysis?

  2 ATP added to glucose phosphate
• What are the products of glycolysis?

  Net gain of 2 ATP, 2 reduced NAD, 2 pyruvate
• Where does the link reaction occur?

  Mitochondrial matrix
• What are the products of the link reaction per glucose molecule?

  2 acetyl-CoA, 2 CO2, 2 reduced NAD
• Where does the Krebs cycle occur?

  Mitochondrial matrix
• What are the products of the Krebs cycle per glucose?

  8 reduced coenzymes, 2 ATP, 6 CO2
• Where does oxidative phosphorylation occur?

  Cristae of mitochondria
• What is the role of reduced coenzymes in oxidative phosphorylation?

  Regenerate NAD and FAD for reactions
• How is ATP made in oxidative phosphorylation?

  Protons move through ATP synthase
• What is the role of oxygen in oxidative phosphorylation?

  Final electron acceptor in the chain
• How does a lack of oxygen affect respiration?

  Stops Krebs cycle and link reaction
• Where does anaerobic respiration occur?

  Cytoplasm
• What happens during anaerobic respiration in plants?

  Pyruvate is reduced to ethanol and CO2
• What happens during anaerobic respiration in animals?

  Pyruvate is reduced to lactate
• How can fatty acids and amino acids be used in respiration?

  They can enter the Krebs cycle