Metabolism

• What is metabolism?

  The sum of all reactions in a cell
• How is energy used in metabolism?

  For enzyme-controlled processes synthesizing new molecules
• What is cellulose used for in plants?

  Structural support in plant cell walls
• How is starch formed in plants?

  By converting glucose molecules
• What are two roles of the liver in metabolism?

  • Converts glucose into glycogen
  • Breaks down excess amino acids into urea
• How are lipids formed in the body?

  From glycerol and three fatty acids
• What does the liver detoxify?

  Poisons like ethanol from alcohol
• How does the liver transfer broken-down substances?

  Via the blood to the kidneys
• What two substances do plants need to make amino acids?

  Glucose and nitrate ions
• What organelle synthesizes proteins from amino acids?

  Ribosome
• Does a person with more muscle have a faster or slower metabolism?

  Faster metabolism due to muscle mass
• What is meant by metabolic rate?

  The speed of metabolism processes
• What factors may affect a person's metabolic rate?

  • Amount of physical activity
  • Body composition (muscle vs. fat)
  • Age
  • Hormonal levels
• How does body mass affect predicted early death?

  Higher body mass may lead to earlier death