Extracting the energy e- Carbohydrate Fat Protein Glucose Fatty acids Amino acids Acetyl CoA ATP Citric acid cycle e- Oxidative Phosphorylation

The 3 stages of Energy Metabolism Large molecules in food are broken down into smaller units (no useful energy generated) These smaller molecules are then degraded to a few simple units that play a central role in metabolism (some energy generated) The citric acid cycle and oxidative phosphorylation then result in production of ATP (most of the energy generation happens here)

Extracting the energy e- Carbohydrate Fat Protein Glucose Fatty acids Amino acids Acetyl CoA ATP Citric acid cycle e- Oxidative Phosphorylation

Glycolysis The sequence of reactions that converts glucose to pyruvate C6H12O6 C3H3O3 6 carbon 3 carbon

Glycolysis 10 steps - 10 enzymes First 5 reactions Add 2 phosphate groups and cleave in half to form glyceraldehyde-3-PO4 Next 5 reactions Generate 2 molecules of ATP from glyceraldehyde-3-PO4 making pyruvate

Citric acid cycle / Krebs cycle The final common pathway for the oxidation of fuel molecules Pyruvate (C3) Acetyl CoA (C2) Acetyl CoA Citric acid cycle

C2 C4 C6 NADH NADH C5 FADH2 NADH C4 NADH and FADH2 are energy rich molecules with electrons that are used in oxidative phosphorylation

Oxidative Phosphorylation The process in which ATP is formed as electrons are transferred from NADH or FADH2 to O2 by a series of 5 multisubunit complexes located on the inner mitochondrial membrane

Oxidative Phosphorylation NADH O2 H2O Complex 1 ADP NAD Ubiquinone Complex 3 Complex 4 Complex 5 Cyt c FADH2 ATP Complex 2 FAD

Glucose, Fatty acids, Amino acids Glycolysis Beta oxidation Pyruvate Acetyl CoA Ketone bodies Citric acid cycle NADH / FADH2 Amino acids Amino acids Oxidative phosphorylation ATP