Glycolysis

Cards (9)

  • During respiration, a chemical reaction occurs in which sugars are oxidised to release ATP
  • Why ATP is the preferred energy source
    • quick release energy
    • small quantities
    • phosphorylates
    • reversible
  • The 4 metabolic pathways of aerobic respiration
    1. glycolysis -> occurs in the cytoplasm
    2. link reaction -> occurs in the mitochondrial matrix
    3. krebs cycle -> occurs in the mitochondrial matrix
    4. electron transport chain -> occurs in the inner membrane of the mitochondria
  • Mitochondria consist of a double layer of membrane surrounding a central matrix, with the inner membrane folding to form cristae
  • Coenzymes = complex organic molecules that are needed for some enzymes to function, they accept or donate subatomic particles
  • Linking between the stages of respiration
    • carrier proteins are used to transfer the substrates between the different parts of the cell
    • the coenzyme NAD is used as an acceptor for hydrogen during the pathways of respiration
    • the reduced NAD formed is used as a donor of hydrogen for the electron transport chain during which most of the ATP is synthesised
  • Glycolysis is the first stage of both aerobic and anaerobic respiration
  • Glycolysis takes place in the cytoplasm and begins with the activation of the main respiratory substrate glucose
  • Process of glycolysis
    1. Glucose is activated, which adds two phosphate groups provided by the hydrolysis of two ATP molecules, producing phosphorylated glucose
    2. The phosphorylated glucose then undergoes hydrolysis to produce two molecules of triose phosphate
    3. These molecules are oxidised from the removal of hydrogen which reduce NAD
    4. This produces two pyruvate molecules which also results in the formation of four molecules of ATP, so there is a net gain of 2 molecules of ATP