This lecture dives into microbial metabolism, the intricate chemical dance cells perform to keep life thriving. It splits into catabolism, where molecules break down to unleash energy, and anabolism, which harnesses that energy to build vital cellular parts. Enzymes take center stage as biological catalysts, speeding up reactions by lowering the activation energy, yet they remain finely tuned to environmental cues such as pH and temperature. The material explores how cells craft ATP through oxidation-reduction reactions and phosphorylation. Key metabolic pathways, such as glycolysis and the Krebs cycle, emerge as microbes' main strategies for transforming nutrients into energy. Additionally, it reveals how inhibitors