Storing And Releasing Energy

Question 1

Why is energy important?

Answer 1

Without energy biological processes, such as photosynthesis and muscle contraction, would not occur. No photosynthesis could lead to plant death

Question 2

Describe photosynthesis and energy

Answer 2

• plants produce glucose Via photosynthesis
• photosynthesis is the process where energy from the light is used to make glucose from water and carbon dioxide
  Light energy is converted into chemical energy in the form of glucose

Over all equation: 6CO2 + 6H2O + energy -> C6H12O6 + 6CO2

• energy is stored in the glucose until the plant release it by respiration

Question 3

Describe ATP

Answer 3

• glucose is broke down to make ATP
• ATP is made up of an adenine base, ribose sugar and three phosphate groups
• ATP is synthesised from ADP and inorganic phosphate molecules using energy. ATP synthase catalyses this reaction. Reaction is called phosphorylation
  The energy is stored as a chemical energy in the phosphate bond

When energy is needed, ATP is broken back down into ADP and inorganic phosphate molecule, via hydrolysis and enzyme ATPase, and energy is released from phosphate bond

Question 4

Describe and explain ATP’s properties

Answer 4

ATP has specific properties that make it a good energy source:

• ATP stores or releases only a small, manageable amount of energy at a time, so no energy is wasted
• its a small, soluble molecule so it can be easily transported around the cell
• its easily broken down, so energy can be easily released
• it can transfer energy to another molecule by transferring one of its phosphate groups
• ATP cant pass out of the cell, so cell always has an immediate supply of energy

Question 5

Describe and explain what the compensation point is?

Answer 5

The particular level of light intensity at which the rate of photosynthesis exactly matches the rate of respiration of a plant

When rate of oxygen production = rate of oxygen usage, oxygen generation is zero. this is the compensation point