Review of Organic Chemistry & Biomolecules Primordial Biomolecules Water is the “cradle of life” - All organisms are about 2/3 water. Pathway metabolites are simple. Of the 21 metabolites involved in glycolysis, gluconeogenesis and TCA cycle, all are 6 carbons - “Small is better” Three major biomolecules/ fuels/nutrients : Carbohydrate Lipid Protein Early ( 18 hr) starvation fuel: Carbohydrate (liver glycogen) Late starvation fuel: Lipid (adipose tissue) and protein (muscle) Other biomolecules include: DNA/RNA, vitamins, xenobiotics (alcohol, etc.)