Microbial Metabolism Chapter 5

Metabolism Metabolism: Is the sum of all chemical reactions in the body. metabolism is divided into two types of classes: catabolism and anabolism.

Catabolism is the chemical reactions that break down large compounds and release energy. Anabolism is the chemical reactions that require energy to build large compound Catabolic reactions furnish the energy needed to drive anabolic reactions. . Energy harvested from catabolic reactions are stored in ATP molecules. ATP molecules are used to drive many anabolic reactions.

Oxidation Reduction Energy is often transferred from one molecule to another by oxidationreduction reactions. Energy is transferred when electrons from a molecule being oxidized are shifted to a molecule being reduced. a. Oxidation is the removal of electrons b. Reduction is the gaining of electrons c. Oxidation and reduction always occur together. d. Most microorganisms oxidize carbohydrates as their primary source of energy.

cellular respiration 1.Cellular respiration oxidizes glucose to reduce NAD+ to NADH (NADH is an electron carrier) 2. Cellular respiration has three stages, glycolysis, krebs and electron transport.

Glycolysis Glycolysis is an oxidation reduction reaction. 1. Glucose is oxidized to 2 Pyruvic acids. 2NAD+ are reduced to 2 NADH. produce 2 ATP by substrate level phosphorolation Occurs in the cytoplasm of both procaryotes and eucaryotes

Preparatory step Preparatory step for Krebs cycle: Both pyruvic acid molecules from glycolysis are oxidized into two acetyl CO-A. 2 NAD+ are reduced yielding two NADH Prep step occurs in the Mitochondria.

Krebs cycle Oxidation of 1 acetyl co-A to carbon dioxide produces 1 molecule of ATP 3 NADH 1 FADH Occurs in the cytoplasm in procaryotes Occurs in the mitochondria in eucaryotes

Electron Transport Converts the energy in NADH and FADH molecules into a hydrogen gradient in the mitochondria

Electron Transport Occurs in the plasma membrane of prokaryotes and in the inner mitochondrial membrane in eukaryotes. The hydrogen gradient built up in the mitochondria is responsible for the production of the most of the ATP in the cell.

Electron Transport

Production of ATP H+ ions pass through ATP synthase stimulating it to produce ATP from ADP

Fermintation