2 24 14 Microbial Metabolism Metabolism of Energy Production Microbial Metabolism chemical reactions in a living cell Many microorganisms have some of the same metabolic pathways as humans Two types of metabolism Anabolism building or synthesis reactions o how a cell makes proteins by putting amino acids together Catabolism degradation breaking down reactions o bigger molecule breaks down into smaller molecules ALL reactions require enzymes Energy production metabolism Microbial metabolism breaks down and extracts energy Catabolic End result is ATP energy currency of the cell o ATP can be obtained immediately Chemoheterotrophs o Cellular Respiration humans many microbes aerobic respiration Glycolysis Krebs Cycle TCA or Citric Acid Cycle Electron Transport Chain Microbes have other types of metabolism other than cellular respiration ATP ATP is made up of a sugar ribose a nitrogenous base adenine and a triphosphate group Energy Metabolism of Microorganisms Pathways Cellular Respiration Anaerobic Respiration Fermentation Chemolithotrophy Chemoautotrophy Photosynthesis no details covered ATP ADP Pi What Cells Do with ATP Chemical Work synthesizes molecules Transport Work transport chemicals across membranes uses most energy Mechanical Work movement of cell parts 1 Chemoheterotrophy Cellular Respiration Fermentation Anaerobic Respiration Metabolic Pathways for ATP Production ATP Production Oxidation of organic compounds electron donor Electrons contain the energy of a molecule Example donor glucose 2 Chemolithotrophy chemoautotrophy Oxidation of inorganic compounds electron donor Example donor nitrite 3 Phototrophy photoautotrophy photosynthesis Photons used to boost electrons to higher energy levels which then are transferred to lower levels to produce ATP uses sunlight Example donor water Cellular Respiration Aerobic Respiration Complete breakdown of molecules About 90 of microorganisms use this Preferred molecule for making ATP Carbohydrates Monosaccharide Glucose End up with carbon dioxide and water as low energy end products Cellular Respiration Figure 8 12 in book 3 Parts 1 Glycolysis the splitting of glucose Makes 2 ATP End product is 2 pyruvic acids 2 NADH are produced NADH is a temporary energy storage molecule It is used later on in cellular respiration 2 Krebs Cycle circular cycle Pyruvic acid starts the cycle Makes 2 ATP Carbon dioxide is given off waste gas FADH2 and NADH are produced Both are temporary holdings of energy and are used later on 3 Electron Transport Chain shuttles electrons from molecule to molecule NADH and FADH2 start the electron transport chain Slowly extracts electrons Oxidation Reduction Reaction Oxygen gas is needed in the last step to make water Oxygen is the final electron acceptor Lots of ATP is made 34 Anaerobic Respiration Only carried out by a few species of bacteria archea Same as cellular respiration except No oxygen Uses other inorganic compounds used in last step of electron transport chain Nitrate NO3 nitrate reducing bacteria NO3 NO2 H2O Sulfate SO4 Fermentation Many microbes depend on it Still uses organic molecules Anaerobic When no oxygen is around Partial catabolism of carbohydrates Energy yield much smaller than cellular respiration doesn t make as much ATP Glycolysis is present needs NAD Only substrate level phosphorylation No Krebs Cycles or Electron Transport Chain used the big difference between fermentation and cellular respiration Organic end products given off lots Acids alcohols gasses ketones aldehydes o lactate Y Replenishment of NAD Needed to keep glycolysis running Pyruvate converted to other products end products Results in more NAD
View Full Document
Unlocking...