Metabolism

• What is metabolism and what is it controlled by

  • Metabolism is the sum of all the chemical reactions in a cell or in the body  
  • These reactions in metabolism are controlled by enzymes and many need a transfer of energy 
  • This energy is transferred by respiration and is used to make new molecules
• Where do many chemical reactions in the body get the energy to make new molecules?

  Respiration
• Why is glucose an important chemical in metabolism

  • Glucose is an important chemical in metabolism 
  • Energy is released from glucose in respiration , which can be used to make new molecules
  • Glucose is also the starting point for many new molecules / chemicals

  
• What are the 3 ways that glucose is converted in plant cells?

  • In plant cells. glucose is converted into cellulose , which strengthens the plant’s cell wall 
  • In plant cells, glucose is converted into starch , which is a storage form of glucose 
  • In plant cells, glucose is reacted with nitrate ions to make amino acids which are used to synthesise proteins 

  
• What is glucose converted into in humans?

  In humans, glucose is converted into glycogen , which is a storage form of glucose

  
• In metabolism, what are glycerol and fatty acid molecules converted into?

  In metabolism, 1 glycerol molecule is reacted with 3 fatty acid molecules to form a lipid molecule , which are found in the cell membrane
• In metabolism, what are proteins converted into

  • Humans don’t need to eat a large amount of protein 
  • In metabolism, excess proteins are broken down into urea , which is then excreted by the kidneys