Metabolism and Exercise

• What is metabolism?

  The sum of all reactions in a cell
• What do metabolic reactions use to make new molecules?

  Energy from respiration
• Which molecules combine to make amino acids?

  Glucose and nitrate ions
• What are lipids broken down into?

  Glycerol and fatty acids
• What do glucose molecules join together to form?

  Bigger carbohydrates like starch or glycogen
• What happens to energy needs during exercise?

  • More energy is needed
  • More aerobic respiration occurs
  • More oxygen is required
• What increases to supply more oxygen to muscles during exercise?

  Heart rate, breathing rate, and breath volume
• What is muscle fatigue?

  Muscles get tired and stop contracting efficiently
• What is oxygen debt?

  Extra oxygen needed to remove lactic acid
• What occurs during vigorous exercise regarding oxygen supply?

  Not enough oxygen is supplied to muscles
• What is metabolism?

  The sum of all the reactions that happen in a single cell or the body
• What are some examples of metabolic reactions?

  Glucose and nitrate ions combined to make amino acids, then made into proteins, Lipids broken down into glycerol and fatty acids, Glucose molecules joined together to make bigger carbohydrates (e.g. starch or glycogen)
• What happens to the body during exercise?

  More energy is needed, more aerobic respiration is needed, and more oxygen is needed
• What are the three things that increase to get more oxygen to the muscles during exercise?

  1. Heart rate, 2. Breathing rate, 3. Breath volume
• What is muscle fatigue?

  The muscles get tired and stop contracting efficiently during long periods of exercise
• What is oxygen debt?

  The amount of extra oxygen needed to react with built-up lactic acid and remove it from cells
• What happens during anaerobic respiration in the muscles during vigorous exercise?

  Lactic acid builds up in the muscles
• How does the body deal with the lactic acid buildup from anaerobic respiration during exercise?

  The heart rate and breathing rate stay high after exercise to repay the oxygen debt, and the liver converts the lactic acid to glucose
• What are the key components of metabolism?

  • Metabolic reactions use energy from respiration to make new molecules
  • Examples include:
  • Combining glucose and nitrate ions to make amino acids and proteins
  • Breaking down lipids into glycerol and fatty acids
  • Joining glucose molecules to make larger carbohydrates like starch or glycogen
• How does the body respond to the increased energy demands of exercise?

  • Heart rate, breathing rate, and breath volume increase to get more oxygen to the muscles
  • This is needed to support the increased aerobic respiration required during exercise
  • Anaerobic respiration also occurs, leading to lactic acid buildup and oxygen debt
• What are the effects of long periods of exercise on the body?

  • Muscle fatigue - the muscles get tired and stop contracting efficiently
  • Oxygen debt - the extra oxygen needed to react with and remove built-up lactic acid
  • The body deals with this by:
  • Keeping heart rate and breathing rate elevated after exercise to repay the oxygen debt
  • The liver converting lactic acid to glucose