Vet 104 – Cell Metabolism Metabolism – the sum of all the biochemical reactions that occur within an organism, including the synthetic (anabolic) & decomposition (catabolic) reactions. Anabolism – synthetic energy-requiring reactions whereby small molecules are built up into larger ones. Catabolism – chemical reqactions that break down complex organic (carbon-containing) compounds into simple ones w/ the release of energy.

Simple compounds complex compounds Anabolism Catabolism Energy ADP +P ATP

Enzymes: Def. – a substance (usually a protein) that affects the speed of a chemical reaction; a catalyst. Apoenzyme – protein portion Cofactor – non-protein (ion – Ca++, vitamins) Holoenzyme – whole enzyme, active Substrate – molecules that are changed by the enzyme (specific). +/- energy

Energy Production (ATP) Adenosine P P + energy + P Adenosine P P P (ADP) (ATPase) (ATP) Oxidative phosphorylation – addition of a phosphate group using the energy generated by the transfer of electrons from one acceptor to another. (mitochondria) Glycolysis Krebs Cycle Electron Transport Chain (Citric Acid Cycle) FOOD ENERGY

Electron Transport Chain Simple compounds complex compounds Anabolism Catabolism Energy ADP +P ATP Electron Transport Chain Glucose NADH + FADH2 Glycolysis, Krebs

38 ATP’s GLUCOSE FADH2

Glycolysis & Kreb’s cycle Electron transport chain

NET PRODUCTION of ATP from 1 GLUCOSE MOLECULE: 38 NADH = 3 ATP’s FADH2 = 2 ATP’s Reduced coenzymes – H atoms contain energy NET PRODUCTION of ATP from 1 GLUCOSE MOLECULE: 38 1 glucose (glycolysis) = 2 pyruvic acids + 2ATP + 4 NADH 2 pyruvic acids (krebs cycle) = 6 NADH + 2 FADH2 + 2 GTP 10 NADH + 2 FADH2 (electron transport ) = 34 ATP