Chapter 9: Respiration

• What is Respiration?

  A series of chemical reactions that transfers energy to your cells.
• Where does aerobic respiration take place?

  Mitochondria
• What do organisms need energy for?(3)

  • chemical reactions to build larger molecules
  • muscle contraction for movement
  • keeping warm
• Why is respiration called exothermic?

  Release of energy.
• Write the word equation for aerobic respiration.

  glucose + oxygen ➞ carbon dioxide + water
• Write the word equation for anaerobic respiration in muscles.

  glucose ➞ lactic acid
• Write the balanced symbol equation for aerobic respiration.

  C6 H12O6 + 6O2 ➞ 6CO2 + 6H2 O
• Why does aerobic respiration release more energy per glucose molecule than anaerobic respiration?

  oxidation of glucose is complete in aerobic respiration and incomplete in anaerobic respiration
• What is anaerobic respiration in yeast cells called?

  Fermentation
• Write the word equation for anaerobic respiration in plant and yeast cells.

  glucose ➞ ethanol + carbon dioxide
• How does the body supply the muscles with more oxygenated blood during exercise?(3)

  heart rate, breathing rate, and breath volume increase
• What substance builds up in the muscles during anaerobic respiration?

  Lactic acid
• What happens to muscles during long periods of activity?(2)

  muscles become fatigued and stop contracting efficiently
• What is oxygen debt?

  amount of oxygen the body needs after exercise to react with the accumulated lactic acid and remove it from cells
• How is lactic acid removed from the body?

  lactic acid in muscles ➞ blood transports to the liver ➞ lactic acid converted back to glucose
• What is metabolism?

  sum of all the reactions in a cell or the body
• How can Limewater be used to show respiration is taking place?

  When limewater goes cloudy, CO₂ is present. CO₂ is also a product of respiration.
• Why is yeast needed to make beer?

  When yeast respires ethanol & CO₂ are produced. Ethanol makes the beer alcoholic.
• Why is yeast needed to make bread?

  Yeast is needed to make bread because it ferments the dough, producing carbon dioxide gas which causes the bread to rise.
• How does liquid parrafin keeps the yeast respiration anaerobic?

  The parrafin acts as a barrier between oxygen and the glucose solution with yeast. No oxygen means respiration stays anaerobic.
• What is glycogen?

  The storage carbohydrate in muscles
• Why is respiration effective in the mitochondria?

  High concentration of enzymes & Large Surface Area
• Similarities between anaerobic respiration in humans & yeast?(3)

  • Both reactions have glucose as a SUBSTRATE
  • Neither reactions use oxygen
  • Both release energy
• Differences between anaerobic respiration in humans & yeast?(2)

  • Lactic Acid is produced in human anaerobic respiration
  • Ethanol & carbon dioxide are produced in yeast anaerobic respiration.
• Similarities between anaerobic respiration and aerobic?(2)

  • Both release energy
  • Both use glucose as a SUBSTRATE
• Differences between aerobic and anaerobic respiration.(4)

  • aerobic respiration produces more energy per moleule of glucose than anaerobic (3x)
  • Anaerobic doesn'tt have oxygen as a reactant but aerobic does
  • Both produce different product:

  Aerobic respiration: Carbon Dioxide + Water

  Anaerobic respiration: Lactic Acid (in humans)
• How are oxygen and glucose transported around our body?

  Bloodstream
• Changes when exercising:

  • Heart rate increases & arteries to muscles dilate to increase flow of oxygenated blood to muscles
  • Breathing rate increases (breathe more often)
  • Breathe more deeply (more air in lungs)
  • Glycogen stored in the muscles is converted back to glucose (used for respiration)
• What are the 2 types of chemical reactions in the body?

  Catabolic & Anabolic
• What is a Catabolic reaction?

  Breakdown of molecules.

  E.g. Digestion
• What is an Anabolic reaction?

  Building up molecules or storing energy.

  E.g. Muscle growth, DNA replication, Proteinsynthesis
• What type of reaction is converting glucose to starch and cellulose in plants or glycogen in animals?

  Anabolic
• What type of reaction is the formation of lipids from glycerol and fatty acid chains?

  Anabolic
• What type of reaction is the formation of amino acids from glucose and nitrate ions?

  Anabolic
• What type of reaction is Respiration?

  Catabolic
• What type of reaction is Photosynthesis?

  Anabolic
• What type of reaction is the breakdown of excess proteins into urea for excretion by the kidneys (animals only)?

  Catabolic
• What does the liver do?

  • Breaks down toxic substances (E.g. Ethanol)
  • Passes breakdown products into blood
  • Breaks down old red blood cells & stores the iron until new red blood cells are made
  • Produces bile
  • Stores substances (E.g. glycogen, some vitamins and minerals)
• What does bile do?

  • Neutralises pH
  • Emulsifies lipids
• How does bile emulsify lipids?

  Breaks down fats into small droplets —> Increases surface area for rapid digestion