Key area 6: respiration

• What is respiration?


  The chemical release of energy from the food we eat
• Where is the chemical energy for respiration found?

  stored in glucose and released through a series of enzyme-controlled reactions
• How is ATP made?

  by the energy that's released from the breakdown of glucose
• How is ATP made?

  By joining ADP and Phosphate
• What can energy from the breakdown of ATP be used for?

  Muscle cell contraction

  Cell division

  Protein synthesis

  Transmission of nerve impulses
• When does aerobic respiration take place?

  In the presence of oxygen
• Word equation for aerobic respiration?

  Glucose + Oxygen -> Carbon Dioxide + Water + Energy
• The two stages of aerobic respiration?

  Stage 1: glucose is broken down into 2x molecules of Pyruvate ( 2 ATP + 2Pi -> 2ATP) **takes place in cytoplasm - doesn't require oxygen

  
  

  Stage 2: Each pyruvate molecule broken down into carbon dioxide + water (large number of ADP + Pi -> large number of ATP) **takes place in mitochondria - does require oxygen
• What is fermentation?


  when respiration cannot happen due to an absence of oxygen, fermentation takes place
• What's the word equation for fermentation in plant cells?

  Glucose → Ethanol + Carbon Dioxide + Little Energy
• What's the word equation for fermentation in animal cells?


  Glucose → Lactic acid +Little Energy
• What happens in fermentation in animal cells?

  Glucose is broken down into 2 molecules of pyruvate (2ADP + Pi -> 2ATP).

  Pyruvate molecules produce lactate with a lack of oxygen but when there is more oxygen supplied, this is reversed.

  **all happens in the cytoplasm

  
• What are the products of respiration?

  Carbon dioxide, water, and energy.
• What are the products of fermentation in animal cells?

  Lactic acid + little energy
• What are the products of fermentation in plant cells?

  Carbon dioxide + ethanol + little energy
• What happens in fermentation in plant cells cells?

  Glucose is broken down into 2x pyruvate molecules (2ADP + Pi -> 2ATP)

  2x pyruvate molecules produce ethanol + carbon dioxide

  ** happens in the cytoplasm - is irreversible
• Where does respiration occur?


  Mitochondria
• Where does fermentation occur?

  Cytoplasm
• How many ATP molecules are made in fermentation?

  2 ATP