17. Respiration

• What are the four main stages of respiration

  Glycolysis

  link reaction

  Krebs cycle

  oxidative phospholyration
• Where does glycolysis happen

  Cytoplasm
• Where does the link reaction happen

  Matrix
• Where does the Krebs cycle happen

  Matrix
• Where does oxidative phosphorylation happen

  Cristae membrane
• What is the role of the matrix in a mitochondria

  Contains enzymes required for the catalysis of the link reaction
• What is glycolysis

  When a glucose molecule is converted into two pyruvate molecules.
• Explain glycolysis

  There is phosphorylation of glucose by ATP, makes glucose phosphate

  glucose phosphate is Split into two triose phosphate molecules. Both are oxidised by removal of hydrogen to form two molecules of pyruvate
• What are the products of glycolysis

  2 NADH

  4 ATP
• What is the link reaction

  Pyruvate is converted into acetylcoenzymeA
• How is acetylcoemzymeA formed

  pyruvate is oxidised to become acetate when hydrogen is removed. coenzymeA is added
• 2 x NAD

  Two molecules of NAD
• FAD

  Flavin adenine dinucleotide
• NADH

  Reduced form of NAD
• FADH

  Reduced form of FAD
• 5C molecule


  Molecule containing 5 carbon atoms
• CO2

  Carbon dioxide
• 2x NADH

  Two molecules of reduced NAD
• 6C molecule

  Molecule containing 6 carbon atoms
• Decarboxylation

  Removal of a molecule of carbon dioxide from a compound
• 4C compound

  Compound containing 4 carbon atoms
• Oxidation reactions


  Reactions that involve the loss of electrons
• ATP

  Adenosine triphosphate
• Hydrogen atoms removed

  Used to reduce NAD and FAD
• 4C molecule

  Molecule containing 4 carbon atoms
• Substrate level phosphorylation

  Process of producing ATP by transferring a phosphate group from a substrate to ADP
• What happens during the Krebs cycle

  AcetylcoenzymeA reacts with a 4C molecule to produce a 6C molecule. Through a series of oxidation reactions and 2 Carbon dioxide being released 4C molecule is formed again.
• What are the products of Krebs

  Reduced FAD

  3 reduced NAD

  2 CO2

  ATP
• What is oxidative phosphorylation

  When the reduced coenzymes release hydrogen which becomes proton or electron - this passes along the ETC releasing energy. Used to pump protons through membrane. Protons pass through atp synthase. Oxygen acts as terminal electron acceptor
• What is oxygens role in respiration

  Acts as the terminal electron acceptor combines with proton and electron to make water
• How are the products of lipids placed into respiration

  Glycerol - triose phosphate

  fatty acids - either produce carbon fragments or hydrogen atoms
• How are amino acids placed into respiration

  have their amino group removed - enter at different stages depending on carbon they contain
• What happens in the absence of oxygen

  Only glycolysis takes place
• What is the main function of anaerobic respiration

  To regenerate NAD so that glycolysis can continue. Allows ATP to be made
• How does anaerobic respiration happen in animal cells

  Pyruvate is reduced to lactate using hydrogen from reduced NAD reduced NAD is there for oxidised to NAD
• Why must lactic acid be removed from cells?

  Lactic acid is toxic as it has a low ph so can affect enzyme activity
• What happens in anaerobic respiration in plant and yeast cells

  Pyruvate is reduced to ethanol and carbon dioxide using hydrogen from reduced NAD
• How do you work out respiratory Quotient?

  vol of CO2 produced / vol of O2 used
• What is the RQ for glucose / carbs

  1
• What has a respiratory quotient of 0.7

  Triglycerides / lipids