Online microbiology and biology related notes by SAGAR ARYAL
Heme Degradation Hemes are cyclic tetrapyrroles that contain iron and are commonly found as the prosthetic group of hemoglobin, myoglobin and the cytochromes. This small-molecule component of globins, critical for oxygen transport among other functions undergo a complex process of metabolism and degradation. Roughly 80% of heme destined for degradation and excretion comes from senescent … Read moreHeme Degradation
Membrane Carbohydrate Cell membranes are selective barriers that separate individual cells and cellular compartments. Membranes are assemblies of carbohydrates, proteins, and lipids held together by binding forces. Carbohydrates are covalently linked to proteins (glycoproteins) or lipids (glycolipids) and also an important part of cell membranes, and function as adhesion and address loci for cells. The Fluid Mosaic Model describes membranes as a … Read moreMembrane Carbohydrate
Phosphoketolase (Heterolactic) Pathway The phosphoketolase pathway is distinguished by the key cleavage enzyme, phosphoketolase. Phosphoketolase in the pathway cleaves pentose phosphate into glyceraldehyde-3-phosphate and acetyl phosphate which is the prime reaction of the pathway. As a fermentation pathway, it is employed mainly by the heterolactic acid bacteria which carry out heterolactic fermentation. Heterolactic fermentation is a type of lactic acid fermentation in which … Read morePhosphoketolase (Heterolactic) Pathway
Degradation and Deterioration Nature has always provided, in considerable amounts and variety, polymeric materials with interesting compositions and structures. These natural polymers include polysaccharides, such as cellulose, chitin, starch, alginate, galactan, hyaluronic acid, dextran, and gellan, obtained from plants, animals, and microbial sources and polyesters, such as poly(b-hydroxybutyrate) and poly(b-hydroxybutyrate-co-b–hydroxyvalerate), produced by numerous bacteria. In biological … Read moreDegradation and Deterioration
Galactose Metabolism Galactose is a major dietary sugar for humans. The hydrolysis of the disaccharide lactose (in milk) yields galactose and glucose. Galactose and glucose are epimers that differ in their configuration at C-4. Thus the entry of galactose into glycolysis requires an epimerization reaction. This occurs via a four-step pathway called the galactose–glucose interconversion … Read moreGalactose Metabolism
Protein Databases- Types and Importance As biology has increasingly turned into a data-rich science, the need for storing and communicating large datasets has grown tremendously. The obvious examples are the nucleotide sequences, the protein sequences, and the 3D structural data produced by X-ray crystallography and macromolecular NMR. The biological information of proteins is available as sequences … Read moreProtein Databases- Types and Importance
Omega oxidation (ω-oxidation) of fatty acid Omega oxidation (ω-oxidation) is a process of fatty acid metabolism in some species of animals. It is an alternative pathway to beta oxidation that, instead of involving the β carbon, involves the oxidation of the ω carbon (the carbon most distant from the carboxyl group of the fatty acid). The ω (omega)-carbon (the methyl carbon) of fatty acids is … Read moreOmega oxidation (ω-oxidation) of fatty acid
Lineweaver–Burk Plot Since, Vmax is achieved at infinite substrate concentration, it is impossible to estimate Vmax and hence Km from a hyperbolic plot. Because of this difficulty, the Michaelis–Menten equation was transformed into an equation for a straight line by Lineweaver and Burk. The Lineweaver–Burk plot (or double reciprocal plot) is a graphical representation of the Lineweaver–Burk equation … Read moreLineweaver–Burk Plot
Ethanol Metabolism Alcohol is metabolized by several processes or pathways. The most common of these pathways involves two enzymes—alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH). These enzymes help break apart the alcohol molecule, making it possible to eliminate it from the body. First, ADH metabolizes alcohol to acetaldehyde, a highly toxic substance and known carcinogen. Then, … Read moreEthanol Metabolism
Brain Lipid Extraction Protocol “Brain lipid extracts” refers to a lipid mixture extracted from the brain tissue of animals. It has been found that such brain lipid extracts contain a mixture of long chain polyunsaturated fatty acids (PUFAs) that have four or more double bonds and closely resemble the mixture of PUFAs found in human … Read moreBrain Lipid Extraction Protocol