Enzymes and Vitamins

• Metabolism

  This is the process of chemical and physical change which goes on continually in the living organism.
• Enzymes


  The catalysts of biochemical reactions and are responsible for bringing about almost all of the chemical reactions in living organisms.
• Active site


  A region on the surface of an enzyme to which substrates will bind and catalyze a chemical reaction.

  The substrate binds to a specific portion of the enzyme during the reaction.

  A three-dimensional cavity of the enzyme with specific chemical properties that enable it to accommodate the substrate.
• Substrate


  The compound whose reaction is catalyzed.

  The compound on which the enzyme works, and whose reaction it speeds up.
• Ribozymes


  Enzymes made of ribonucleic acids
• Urease


  It catalyzes only the hydrolysis of urea and not that of other amides, even closely related ones.
• Trypsin


  An enzyme that cleaves the peptide bonds of protein molecules-but not every peptide bond, only those on the carboxyl side of lysine and arginine residues.
• Carboxypeptidase 


  It specifically catalyzes the hydrolysis of only the last amino acid on a protein chain-the one at the C- terminal end.
• Lipase


  They catalyze the hydrolysis of any triglyceride, but they still do not affect carbohydrates or proteins.
• Arginase


  It hydrolyzes the amino acid L-arginine (the naturally occurring form) to a compound called L-ornithine and urea but has no effect on its mirror image, D-arginine.
• Jon Jakob Berzelius


  Earliest studies about enzymes were performed in 1835 by him and termed their chemical action catalytic.
• James B. Sumner


  In 1926, the first enzyme was obtained in pure form and was able to isolate and crystallize the enzyme urease from the jack bean.
• John H. Northrop and Wendell M. Stanley


  They Research shared the 1947 Nobel Prize with Sumner. and discovered a complex procedure for isolating pepsin.
• Lactate dehydrogenase 


  It speeds up the removal of hydrogen from lactate.
• Acid phosphatase


  It catalyzes the hydrolysis of phosphate ester bonds under acidic conditions.
• Dehydrogenase


  It is an enzyme that oxidizes a substrate by transferring one or more hydrides (H) to an acceptor, usually NAD+/NADP+ or a flavin coenzyme FAD or FMN.
• Tricarboxylic acid cycle


  It is the three-stage process by which living cells break down organic fuel molecules in the presence of oxygen to harvest the energy they need to grow and divide.
• Oxidase


  It is an enzyme that catalyzes an oxidation-reduction reaction involving molecular oxygen (O2) as the electron acceptor.
• Transaminase


  It is an enzyme that catalyzes a type of reaction between an amino acid and alpha-keto acid.
• Kinase


  It is an enzyme that transfers phosphate groups from high-energy molecules, such as ATP, to specific substrates.
• Lipase


  It is a water-soluble enzyme that catalyzes the hydrolysis of ester chemical bonds in water-soluble substrates. It helps your body digest fats.
• Amylase


  It is an enzyme that breaks starch down into sugar.
• Peptidase


  It is an enzyme that conducts proteolysis. It catalyzes proteolysis, breaking down proteins into smaller polypeptides or single amino acids, and spurring the formation of new protein products.
• Decarboxylase


  It is an enzymes that catalyze decarboxylation of amino acids, beta-keto acids, and alpha-keto acids.
• Isomerase


  It is an enzyme that catalyzes the structural rearrangement of isomers. It facilitates intramolecular rearrangements in which bonds are broken and formed.
• Mutase


  It is an enzyme that catalyzes the shifting/movement of a functional group from one position to another within the same molecule.
• Apoenzyme 


  It is the protein portion of the enzyme.
• Activation


  It is any process that initiates or increases the action of an enzyme.
• Inhibition


  It is the opposite any process that makes an active enzyme less active or inactive.
• Competitive inhibitors 


  They bind to the active site of the enzyme surface, thereby preventing the binding of substrate.
• Noncompetitive inhibitors


  They bind to some other portion of the enzyme surface and sufficiently alter the tertiary structure of the enzyme so that its catalytic effectiveness is eliminated.
• Cofactor


  It is the nonprotein part of an enzyme necessary for its catalytic function.
• Coenzyme


  It is a nonprotein organic molecule, frequently a B vitamin, that acts as a cofactor.
• Inhibitor


  It is a compound that binds to an enzyme and lowers its activity.
• Enzyme-substrate complex


  Catalysts speed up reactions by combining with the substrate to form some kind of intermediate compound.
• Lock-and-key model


  A model explaining the specificity of enzyme action by comparing the active site to a lock and the substrate to a key.
• Induced-fit model


  It is a model explaining the specificity of enzyme action by comparing the active site to a glove and the substrate to a hand.
• Daniel Koshland


  He introduced the induced-fit model, in which he compared the changes occurring in the shape of the cavity upon substrate binding to the changes in the shape of a glove when a hand is inserted.
• Irreversible inhibitor


  It forms covalent or very strong noncovalent bonds. The site of attack is an amino acid group that participates in the normal enzymatic reaction
• Reversible inhibitor


  It forms weak, noncovalent bonds that readily dissociate from an enzyme. The enzyme is only inactive when the inhibitor is present.