Photosynthesis and Cellular Regulation

• What is the full form of ATP?

  Adenosine Triphosphate
• What role does ATP play in cells?

  ATP is one of the main energy currencies in both our cells and plant cells.
• What is the structure of ATP?

  • Adenosine (adenine + ribose)
  • Three phosphate groups bonded together
• What type of bonds are present between the phosphate groups in ATP?

  Phosphoanhydride bonds
• What happens when phosphoanhydride bonds in ATP are broken?

  Energy is released to power other cellular activities.
• What is the equation representing the breakdown of ATP?

  ATP → ADP + Pi → AMP + Pi
• Why are the phosphoanhydride bonds in ATP considered thermodynamically unstable?

  They are easily broken by hydrolysis into ADP and Pi.
• What does it mean that ATP is a kinetically stable molecule?


  It has a high activation energy requirement for its hydrolysis.
• Why is ATP considered a fantastic candidate for energy currency?

  Due to its duality in chemical stability, being thermodynamically unstable yet kinetically stable.
• What is photosynthesis?

  Photosynthesis is the process by which plants, algae, and some bacteria convert light energy from the sun into chemical energy stored in organic molecules such as glucose.
• What are the two stages of photosynthesis?

  1. Light-dependent stage
  2. Light-independent stage
• Where does photosynthesis occur in plant cells?

  In the chloroplasts of cells.
• What are the main components of chloroplasts?

  • Double membrane
  • Thylakoid membranes
  • Grana (stacked thylakoid membranes)
  • Stroma (fluid-filled space)
• What is the function of the thylakoid membranes in chloroplasts?

  They are the location for the light-dependent stage of photosynthesis.
• What is the function of grana in chloroplasts?

  Grana increase the surface area available for light absorption.
• What is the role of the stroma in chloroplasts?

  The stroma contains the enzymes required for the dark stage of photosynthesis.
• Where does the light-dependent stage of photosynthesis occur?

  In the thylakoid membranes.