University:
University of Wolverhampton
Course:
4PY019 | Pharmacy
Academic year:

2023
Views:

221

Pages:

3
Author:

Carisma

Catalase- increases RO chemical reaction without undergoing permenant change Active site- region on enzyme binds to a substrate or cofactor during a reaction Abyzyme- antibody with catalytic activity Isoenzyme- 2 or more enzymes with different amino acid structures catalysing the same reaction Allosteric enzyme/activator/inhibitor-molecule altering enzyme activity by inducing conformational change usually more than one active site Proteolytic enzymes: Papain-generalist from papaya plants used in meat industry Trypsin-specific-peptide bond cleavage- only on carboxyl side of lysine and arginine residues Thrombin-blood clotting catalysing glycine bonds but within specific peptide sequences only Enzymes 20 years half life Moving things faster by heating it, increasing concentration of reactants and adding catalysts Enzymes are proteins catalysing specific chemical reactions in living organisms such as couple reactions, recyclable, highly regulated, highly specific and powerful Chymotrypsin Made in pancreas and works in small intestines to specifically break down dietary proteins the cleft in the enzyme contains active site near side chains of 3 residues HIS 75, ASP 102, SER 195 Catalyses the hydrolysis of peptide bonds at a rate of 190 per second Fast and specific enzymes Carbondic anhydrase Catalyses the hydration of CO2 from tissues to the blood system to alveolar air Amylase breaks down food Pepsin converts food into energy metabolic regulation Glycolysis Biosynthesis i.e. polymerases Post translational modification i.e. kinases phosphorylates, phosphatases removes a phosphate Controllling gene expression i.e. methyl transferases Nomenclature: Prefix denotes what it does most end in ase but some preolytic enzymes end in -in i.e. pepsin Enzyme structure: Active site shape- Michael is-mention (M-M) Hyperbolic plot of reactions velocity Enzyme activity y-axis, substrate conc on x-axis Allosteric site: more than one active site M-M plots are sigmodial Allosteric regulatory molecule: binding of an effector molecule changes the conformational shape of enzyme and regulates action Lock and key and induced fit model Enzymes usually require cofactors for activity Inorganic molecules i.e. metal ion Organic molecule i.e. heme group- prosthetic group Catalysis and free energy: Lower activation energy= faster reaction Co factors may include inorganic molecules such as Mg2+ used by DNA polymerase and Zn2+ and organic molecules such as NAD+ electron transfer i.e. glycolysis Kinetics of an enzyme measured on the basis of substrate concentration M-M describes enzyme activity and measured in terms of {S} M-M equation KM substrate conc at which reaction velocity is half its maximum value M—M derivation based on assumption of one molecule substrate combining with one molecule of enzyme to form ES-complex, excess substrate the amount combines in ES is negligible and VMax is reached Enzyme activity The rate of reaction measured in terms of mass of substrate converted per unit time i.e. mol min-1 Enzyme unit- amount of enzyme that will catalyse the conversion of 1 mol of substrate in 1 min Specific activity is a measure of purity- activity product formed per mg of enzyme present