Saran's Learn Microbiology

OXIDATIVE PHOSPHORYLATION AND ELECTRON TRANSPORT CHAIN (ETC) OXIDATIVE PHOSPHORYLATION Oxidative phosphorylation is the process in which ATP is formed as a result of the transfer of electrons from NADH or FADH 2  to O 2  by a series of electron carriers. This process, which takes place in mitochondria, is the major source of ATP in aerobic organisms. Oxidative phosphorylation is linked with the Electron transport chain (ETC). ELECTRON TRANSPORT CHAIN Electron transport chain (ETC) is the final common pathway in aerobic cells by which electrons derived from various substrates are transferred to Oxygen. The transfer of electrons from one electron carrier to the next releases energy, some of which is used to generate ATP from ADP through a process called Chemiosmosis. ETC is a series of highly organized Oxidation–Reduction reaction. In Eukaryotes, ETC takes place in the Mitochondria but in Prokaryotes, ETC takes place in Plasma membrane. Carrier Molecules in Electron Transport Chain (

FERMENTATION Fermentation is a metabolic process that converts the sugar to acids and gases, or alcohol. Fermentation is also used more broadly to refer to the bulk growth of microorganisms on a growth medium, often with the goal of producing a specific chemical product. French microbiologist Louis Pasteur is often remembered for his insights into fermentation and its microbial causes. The science of fermentation is known as Zymology. 1. ALCOHOLIC FERMENTATION Many fungi and some bacteria, algae, and protozoa ferment sugars to ethanol and CO 2 in a process called Alcoholic fermentation (Example Zymomonas mobilis and Saccharomyces cerevisiae ). Pyruvate is decarboxylated to Acetaldehyde, which is then reduced to Ethanol by Alcohol dehydrogenase with NADH as the electron donor. Alcoholic fermentation by yeasts produces alcoholic beverages; CO 2 from this fermentation causes bread to rise. 2. LACTIC ACID FERMENTATION Lactic acid fermentation, the reduction of pyruvate to lactate,