Respiration

Cards (26)

  • What is aerobic respiration?
    Requires oxygen and produces carbon dioxide, water, and ATP
  • What is anaerobic respiration?
    Takes place without oxygen and produces lactic acid in animals or ethanol and carbon dioxide in plants
  • What is the first stage of respiration?
    Glycolysis
  • Where does glycolysis take place?
    Cytoplasm of the cell
  • What is the first step of glycolysis?
    Phosphorylation of glucose to glucose phosphate by the hydrolysis of 2 ATP molecules
  • What is the second stage of glycolysis?
    Glucose phosphate is hydrolysed to 2 molecules of triose phosphate
  • What is the third stage of glycolysis?
    Triose phosphate is oxidised to 2 pyruvate, 2 NAD are reduced, and 4 ATP are regenerated
  • What are the products of glycolysis and where do they go next?
    2 x pyruvate goes to the link reaction, 2 x ATP is a useful product, and 2 x reduced NAD goes to oxidative phosphorylation
  • Why does glycolysis take place in the cytoplasm and why is it anaerobic?
    It occurs in the cytoplasm because enzymes required are found there, and it is anaerobic as it does not require oxygen
  • What is the next step of aerobic respiration after glycolysis?
    Link reaction
  • Where does the link reaction take place?
    Matrix of mitochondria
  • What happens to the pyruvate during the link reaction?
    Pyruvate is oxidised to acetate, loses a carbon to carbon dioxide, and two hydrogens are accepted by NAD to form reduced NAD
  • What is the last step of the link reaction?
    Acetate combines with coenzyme A to produce acetylcoenzyme A
  • What is the next step of aerobic respiration after the link reaction?
    Krebs cycle
  • Where does the Krebs cycle take place?
    Matrix of mitochondria
  • What happens to the acetylcoenzyme A in the Krebs cycle?
    It reacts with a 4 carbon molecule (oxaloacetate) to produce a 6 carbon molecule (citrate), releasing coenzyme A
  • What happens to the 6 carbon molecule in the Krebs cycle?
    It loses 2x carbon dioxide to give a 4 carbon molecule, FAD and NAD are reduced, and a single ATP is produced
  • What are the two ways of making ATP?
    Substrate level phosphorylation and oxidative phosphorylation
  • Where does oxidative phosphorylation take place?
    Cristae of mitochondria
  • Where do protons come from in oxidative phosphorylation?
    From the oxidation of reduced NAD and reduced FAD, where hydrogen ions are released
  • How is energy released for chemiosmosis?
    Electrons pass along an electron transfer chain through a series of redox reactions, releasing energy
  • What happens during chemiosmosis?
    Protons are pumped from the matrix into the inner membrane space, building up an electrochemical gradient
  • What happens at the end of the electron transport chain?
    Electrons combine with protons and oxygen to form water
  • Why is oxygen needed in oxidative phosphorylation?
    It’s the final electron acceptor for the electron transport chain
  • What is the first stage of anaerobic respiration?
    Glycolysis
  • What happens after glycolysis if no oxygen is present?
    Pyruvate is converted into lactic acid in animals or ethanol and carbon dioxide in plants, and reduced NAD is oxidised to NAD