Cell respiration is typically explained according to the oxidation of a carbohydrate (glucose), however lipids and proteins can also be used as energy sources
Carbohydrates are preferable as a ready-made energy source because:
- They are easier to transport and digest (unlike lipids)
- They don’t produce nitrogenous wastes (unlike proteins)
Destination
- Carbohydrates can be broken down into monosaccharides (e.g. glucose), which are able to be used in glycolysis
- Lipids (i.e. triglycerides) can be broken down into glycerol and fatty acids, which are able to be used in aerobic respiration
- Proteins can be broken down into amino acids, which are also capable of being used in aerobic respiration
Energy Content
- Lipids produce roughly twice as much energy (~4000 kJ per 100 g) as proteins and carbohydrates
- Both proteins (~1,720 kJ per 100 g) and carbohydrates (~1,760 kJ per 100 g) produce similar levels of energy
Role of Organic Molecules in Energy Production
