Microbiology Part 2

 

METABOLISM AND ENERGY PRODUCTION

A.   ATP generation 1.    SUBSTRATE LEVEL PHOSPHORYLATION- releases energy through direct transfer of high energy phosphate groups from an intermediate metabolic cmpd to adenosine diphosphate (ADP) NO molecular oxygen or other inorganic final electron acceptor is required   2.    OXIDATIVE PHOSPHORYLATION- removes electron from organic cmpd and passes them to series of electron acceptors along electron transport chain. NEEDS Molecular oxygen or some other inorganic cmpd as final acceptor

B.   FERMENTATION- energy producing oxidative squences, in which organic compoundsaserves as both electron donors and acceptors. ABSENT of external electron acceptor              1.    GLYCOLYSIS- first step in fermentation and respiration        Oxidation of glucoseà PYRUVIC ACID + 2 moles ATP           Different pathways: a.    Embden- Meyerhof (glycolytic pathway)à MAJOR pathway b.    Etner-Doudoroff- alternate c.    HEXOSE MONOPHOSPHATE SHUNTused with glycolytic pathway – alternative 2.    SECONDARY fermentation PYRUVATEàoxidize toàreduced nicotinamide adenine dinucleotide (NADH) a.    Lactic acid fermentation PYRUVATEà LACTATE Lactobacillus, Streptococcus b.    Alcohol fermentation- PYRUVATEà ETHANOL+CO2 Saccharomyces c.    Etc

C.   Respiration- energy producing oxidative sequences Inorganic cmpds act as the last electron acceptor in a series of reactions. This process includes glycolysis, TCA cycle amd electron transport system, yields ATP   1.    Aerobic respiration a.    TCA Cycle------Pyruvateàconverted toàAcetyl Coenzyme A +CO2 +water 2.    Anaerobic respiration- Inorganic electron acceptor other than Oxygen serves as final electron acceptor