Respiration

• What is anaerobic respiration?

  An exothermic reaction where glucose is broken down to release energy in the absence of oxygen
• What is cellular respiration?

  • A series of chemical reactions that release / transfer energy from glucose
  • Occurs continuously in all living cells
  • Exothermic reaction
• Describe how energy released in respiration is used

  • Chemical reactions to build larger molecules (eg. metabolism)
  • Keeping warm (birds and mammals only)
  • Movement eg. muscle contraction in animals
• State the word equation for aerobic respiration

  • Glucose + Oxygen -> Carbon Dioxide + Water
  • (Occurs in mitochondria)
• State word equations for anaerobic respiration in animals, plants and yeast

  • ANIMALS: Glucose -> Lactic Acid
  • PLANTS + YEAST: Glucose -> Ethanol + Carbon Dioxide
  • (Occurs in cytoplasm)
• Compare the processes of aerobic and anaerobic respiration

  Complete Table (Start with Aerobic) ->

  A) Oxygen

  B) Glucose

  C) Complete

  D) High

  E) CO2

  F) Water

  G) Oxygen

  H) Incomplete

  I) Low

  J) Lactic Acid

  K) Ethanol

  L) CO2

  
• Explain the economic importance of anaerobic respiration in yeast

  • Fermentation (anaerobic respiration in yeast) is used in...
  • Production of bread → CO2 makes dough rise
  • Production of alcoholic drinks → ethanol is a type of alcohol
• Explain how the body reacts to increased energy demand during exercise

  • Increased heart rate → increased blood flow to muscles / lungs
  • Increased breathing rate and volume → more air / oxygen enters lungs
  • To supply more blood containing more oxygen (and glucose) to muscles
  • For more aerobic respiration to release energy / to reduce anaerobic respiration & lactic acid build up
• What happens when muscles are supplied with insufficient oxygen?

  • Anaerobic respiration → oxidation of glucose is incomplete
  • Causing a buildup of lactic acid which causes:
  • Oxygen debt
  • Muscles become fatigued and stop contracting efficiently (if activity long / vigorous)
• What is oxygen debt?

  • Amount of extra oxygen the body needs after exercise to react with lactic acid and remove it from cells
• What is the role of the liver in recovering from vigorous exercise?

  1. Blood flowing through muscles transports lactic acid to the liver
  2. Where it is converted back to glucose
• What is metabolism?

  • Sum of all chemical reactions in a cell or the body
• How else do cells use energy transferred by respiration?

  • To continually carry out enzyme-controlled processes of metabolism that synthesise new molecules
• Give examples of metabolic reactions

  Complete the table ->

  A) Glucose

  B) Starch

  C) plant

  D) glycogen

  E) animal

  F) cellulose

  G) cell walls

  H) 1 glycerol

  I) 3 fatty acid

  J) lipid

  K) Glucose

  L) nitrate ions

  M) amino acids

  N) proteins

  O) respiration

  P) excess proteins

  Q) urea

  R) excretion

  
• Plants convert glucose into starch, and

  animals convert glucose into glycogen.

  Explain why this is necessary. (2)

  • Both storage molecules
  • Converted back to glucose when energy needed