Proteins

• Excess amino acids are deaminated in liver and keto acids produced can be metabolised to glycogen/fat for storage (requires ATP so reduces net production), when fasting or doing vigorous exercise, muscle tissue can be respired
• Some amino acids can be converted to pyruvate, some to acetate and some enter the Krebs cycle directly, one molecule has slightly more hydrogen than one glucose molecule; so little more ATP produced per protein molecule