The size of these fragments varies hence generate a biological bar code of restriction enzyme- digested DNA fragments. This pattern is unique to each individual. Restriction enzymes are fore sighted to be an integral part of the modern genetics. (3,
The triad is located in the active site of the enzyme, where catalysis occurs, and is preserved in all superfamilies of serine protease enzymes. The triad is a coordinated structure consisting of three amino acids: His 57, Ser 195 (hence the name "serine protease") and Asp 102. These three key amino acids each play an essential role in the cleaving ability of the proteases. While the amino acid members of the triad are located far from one another on the sequence of the protein, due to folding, they will be very close to one another in the heart of the enzyme. The particular geometry of the triad members are highly characteristic to their specific function: it was shown that the position of just four points of the triad characterize the function of the containing
Once a product has been formed, they leave the active site of the enzyme hence more reactions can occur. There are two specific theories as to how enzymes interact with substrates. Generally, the lock and key model is the best to describe the interaction between an enzyme and a substrate. In this model, the active site of an enzyme is shaped to bind to specific substrates (Castro). Enzymes themselves are not consumed in the reaction.
The purpose of continuous enzyme assay to study B-galactosidase is to determine the rate of enzyme action (B-galactosidase) at different substrate concentrations of o-Nitrophenylgalactoside (ONPG). The experiment is conducted by adding of the enzyme into the substrate preparation quickly and measure the change in absorbance of the reactants as a function of time. By plotting the
Enzymes are homogeneous biological catalyst that work by lowering the activation of a reaction pathway or providing a new pathway with a low activation energy. Enzymes are special biological polymers that contain an active site, which is responsible for binding the substrates, the reactants, and processing them into products. As is true of any catalyst, the active site returns to its original state after the products are released. Many enzymes consist primarily of proteins, some featuring organic or inorganic cofactors in their active sites. However, certain ribonucleic acid (RNA) molecules can also be biological catalysts, forming ribozymes.
Catalase Activity on Substrate Based On Gas Pressure Production Rate Name of the Class Author’s Name Date Enzymes are organic compounds which act as catalysts and speed up biological reactions in biological organisms. They are not destroyed or changed during the reaction but rather they are used over and over again to catalyze many more reactions. Their activity may be affected and altered by factors such as temperature, substrate concentration, enzyme concentration and Ph. Example of enzymes involved in biological processes are classified into; oxidoreductases, transferases, hydrolases, lyases, isomerase and ligases. Catalase an oxidoreductase and among the vital enzymes in the body, it catalyses the breakdown of hydrogen peroxide
Unlike microtubule, microfilament rarely exists in single individual fiber, rather they are bundled and cross linked to form a complex network. Microfilaments are the polymerized form of a globular protein, called actin, which is the most abundant cellular protein, highly conserved and ubiquitously present in all eukaryotes throughout the evolution. Recently, prokaryotic homologues of actin, MreB and ParM, have been identified and shown to play a crucial role in cell division and cell shape maintenance. Actin in monomeric and polymeric forms is associated with hundreds of accessory proteins, called as actin binding proteins, which enable microfilament to perform its diverse functions. On one hand some of the proteins that bind monomeric actin, inhibit the actin filament formation, on the other, there are actin monomer binding proteins that facilitate actin polymerization process at a particular place depending on the external stimuli and internal requirements.
It is a highly regulated and controlled system to avoid any unwanted protein degradation. First it must be primed for action by E1 ubiquitin activating enzyme. This process also requires energy in the form of Adenosine Triphosphate (ATP). E1 activating enzyme Ubiquitin Figure 15: Schematic representation of activation of Ubiquitin by E1 activating enzyme The activated Ubiquitin is then transferred from the E1 onto a second enzyme called E2 ubiquitin conjugating enzyme. This enzyme acts as an escort for ubiquitin to its next destination E3 ligase enzyme.
Protein synthesis Introduction Translation or protein synthesis is a central process of central dogma of molecular biology. It deals with production of proteins or chains of amino acids by making use of a mRNA as a template, ribosomes as protein synthesizing machinery and tRNA’s as carriers of amino acids during the translation process Living cells devote about 90 % of their chemical energy to synthesis of proteins and only about 10 % to other biosynthetic processes. More than 35% of the dry weight of the cell consists of ribosomes, proteins involved in translation process and tRNA molecules. This suggests that protein synthesis is an important process for the survival of microorganisms Protein synthesis process in
The oxidation of these molecules is primarily used to transform the energy contained in these molecules into ATP. ATP os a large source of energy for muscle contractions and can therefore be referred to as "energy currency" of the cells. The fuel molecules is first converted into acetyl-CoA and then can be inserted in the Krebs Cycle. Looking at the path of a nutrient, such as glucose, the oxidation of the molecule takes place in the glycolysis. The product of the glycolysis is pyruvate.