a. 2 ATP added to glucose (6C) to energize it.
b. Glucose split to 2 PGAL (3C). (PGAL = phosphoglyceraldehyde)
c. H+ and e- (e- = electron) taken from each PGAL & given to make 2 NADH.
d. NADH is energy and e- carrier.
e. Each PGAL rearranged into pyruvate (3C), with energy transferred to make 4 ATP (substrate phosphorylation).
f. Although glycolysis makes 4 ATP, the net ATP production by this step is 2 ATP (because 2 ATP were used to start glycolysis). The 2 net ATP are available for cell use.
g. If no oxygen is available to the cell, the pyruvate will be fermented by addition of 2 H from the NADH (to alcohol + CO2 in yeast or lactate in muscle cells). This changes NADH back to NAD+ so it is available for step c above. This keeps glycolysis going!
h. If oxygen is available to the cell, the pyruvate will move into the mitochondria & aerobic respiration will begin.
[Simple Diagram of Glycolysis]
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Summary of Glycolysis
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| 1. One glucose (6C) converted into 2 pyruvates (3C). |
| 2. Net yield of 2 ATP for use by cell. |
| 3. Two NAD+ are converted into 2 NADH & 2H+. (These go to Electron Transport.) |
During glycolysis, addition of a phosphate to ADP to make ATP is known as substrate phosphorylation.
[Anaerobic Respiration (Fermentation)] [Aerobic Respiration]