Online microbiology and biology related notes by SAGAR ARYAL
Uronic Acid Pathway Uronic acids are a class of sugar acids with both carbonyl and carboxylic acid functional groups. They are sugars in which the terminal carbon’s hydroxyl group has been oxidized to a carboxylic acid. Oxidation of the terminal aldehyde instead yields an aldonic acid, while oxidation of both the terminal hydroxyl group and the aldehyde yields an aldaric acid. The names of uronic acids … Read moreUronic Acid Pathway
Nitrogen Cycle- Steps and Significance The movement of nitrogen between the atmosphere, biosphere, and geosphere in different forms is called the nitrogen cycle and is one of the major biogeochemical cycles. It may also be considered as the movement of nitrogen through the food chain from simple inorganic compounds, mainly ammonia, to complex organic compounds. This complex cycle involves bacteria, plants and … Read moreNitrogen Cycle- Steps and Significance
Oxidative Phosphorylation The NADH and FADH2, formed during glycolysis, β-oxidation of fatty acids and the TCA cycle, give up their electrons to reduce molecular O2 to H2O. Electron transfer occurs through a series of protein electron carriers, the final acceptor being O2; the pathway called as the electron transport chain (ETC). The function of ETC … Read moreOxidative Phosphorylation
Beta-oxidation of Fatty Acid Beta-oxidation is the catabolic process by which fatty acid molecules are broken down in the cytosol in prokaryotes and in the mitochondria in eukaryotes to generate acetyl-CoA. Acetyl-CoA enters the citric acid cycle while NADH and FADH2, which are co-enzymes, are used in the electron transport chain. It is referred as “beta oxidation” because the beta carbon of the fatty acid undergoes oxidation to a carbonyl group. Figure: Schematic demonstrating … Read moreBeta-oxidation of Fatty Acid
Fat soluble vitamins- Vitamin A, D, E and K Vitamins refer to any of a group of organic compounds which are essential for normal growth and nutrition and are required in small quantities in the diet. Vitamins are biologically important. Although a micronutrient, it enhances the metabolism of macronutrients like proteins, carbohydrates and fats. Vitamins … Read moreFat soluble vitamins- Vitamin A, D, E and K
Enzymes- Properties, Classification and Significance Enzymes are the biological macromolecules which speed up the rate of biochemical reactions without undergoing any change. They are also called as biological catalysts. An enzyme is a highly selective catalyst that greatly accelerates both the rate and specificity of metabolic reactions. Properties of Enzymes Nearly all enzymes are proteins, although … Read moreEnzymes- Properties, Classification and Significance
Purine Synthesis There are two pathways of synthesis of purine nucleotides: De Novo synthesis pathway, and Salvage pathway. The De novo synthesis of Purine The de novo synthesis of purine nucleotide means using phosphoribose , amino acids , one carbon units and CO2 as raw materials to synthesize purine nucleotide from the beginning. It is … Read morePurine Synthesis
Cholesterol Synthesis Although cholesterol is synthesized in most tissues of the body where it serves as a component of cell membranes, it is produced mainly in the liver and intestine. Cholesterol and cholesterol esters are transported in blood lipoproteins. All the carbons of cholesterol are derived from acetyl-CoA. The key intermediates in cholesterol biosynthesis are … Read moreCholesterol Synthesis
Pentose Phosphate Pathway The pentose phosphate pathway is a metabolic pathway parallel to glycolysis which generates NADPH and pentoses (5-carbon sugars) as well as ribose 5-phosphate. The pentose phosphate pathway is also called as the phosphogluconate pathway or hexose monophosphate shunt. While it involves oxidation of glucose, its primary role is anabolic rather than catabolic. It is an important pathway that generates precursors for nucleotide synthesis andis especially important in red blood cells (erythrocytes). Location Cytoplasm of … Read morePentose Phosphate Pathway
Urea Cycle- Enzymes and Steps The urea cycle is the metabolic pathway that transforms nitrogen to urea for excretion from the body. Nitrogenous excretory products are removed from the body mainly in the urine. Ammonia, which is very toxic in humans, is converted to urea, which is nontoxic, very soluble, and readily excreted by the … Read moreUrea Cycle- Enzymes and Steps