Download Review sheet – Chapter 6

Review sheet – Chapter 6
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Understand that cellular respiration is the process by which energy is harvested by cells from
sugar; this process requires O2 and releases CO2 and H2O as by-products while producing large
amounts of ATP
Understand that living organisms require ATP for all its activities (including sleeping, breathing,
etc)
Understand that energy is contained in the arrangement of electrons in the chemical bonds that
hold an organic molecules, such as glucose, together; this is referred to as chemical energy
Know the 3 stages of cellular respiration in eukaryotes: Glycolysis, Citric Acid Cycle, and the
Electron Transport Chain (ETC)
Understand that only glycolysis occurs in the cytoplasm, and that the Citric Acid Cycle and the
ETC occur in the mitochondria (of eukaryotes!; prokaryotes do not have mitochondria, or other
organelles for that matter)
Know that glycolysis is the process of breaking down a molecule of glucose (a 6-carbon
molecule) into 2 molecules of pyruvate (a 3-carbon molecule)
Know that glycolysis is universal among all living organisms – every living organism produces
ATP via glycolysis (even prokaryotes, even plants that photosynthesize, even organisms without
oxygen available to them, EVERYONE!!!)
Know that glycolysis does not require oxygen; oxygen gas is required in the ETC, because oxygen
is the final electron acceptor in the chain; the transfer of electrons (energy) enable the
production of ETP
Understand that glycolysis produces 2 ATP per molecule of glucose (and 2 pyruvate molecules)
Understand that the Citric Acid Cycle also produces 2 ATP molecules, but uses pyruvate (from
glycolysis) to produce NADH and FADH2; 2 very high energy molecules
Understand that the ETC uses NADH and FADH2 (produced in the Citric Acid Cycle) to generate
32-34 ATP
Understand that fermentation is the process that converts the energy of pyruvate (produced in
glycolysis) into ATP production in the absence of oxygen
Understand that fermentation follows glycolysis (glycolysis is universal!) and uses the pyruvate
produced during glycolysis to generate more ATP and give off CO2 and ethyl alcohol (“alcohol
fermentation”, bacteria and yeast) or lactic acid (“lactic acid fermentation”, muscle cells)
Know that lactic acid is toxic but can be removed by the liver and converted back to pyruvate
(which will enter the Citric Acid Cycle when oxygen is available)
Understand that oxygen is not required in glycolysis or the Citric Acid Cycle, but the products of
the citric acid cycle enter the ETC where oxygen is needed (if no oxygen is available, organisms
will perform cellular respiration via glycolysis and fermentation – if capable)