Fates of Pyruvate - 4. Ethanol Production
KEY FATES OF PYRUVATE
1. Acetyl CoA: substrate for citric acid cycle and fatty acid synthesis
2. Oxaloacetate: intermediate in CAC and substrate for gluconeogenesis
3. Lactate: produced by eukaryotes in absence of oxygen
4. Ethanol: produced by yeast and some bacteria (including intestinal flora) in absence of oxygen.
- There are aerobic and anaerobic conditions.
Ethanol production (yeast and select bacteria)
- Anaerobic conditions
- Can occur in intestinal flora
- Glycolysis: 1 glucose = 2 pyruvates + 2 ATP + 2 NADH
- 2 step rxn: pyruvate to acetaldehyde to ethanol
- Ethanol formation consumes 2 NADH in second step and produces 2 NAD+ for reuse
- Irreversible reaction
- Fermentation in yeast used to make beer and wine