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42 Cards in this Set
- Front
- Back
Primary stucture of protein |
Simple Chain of amino acids linked by peptide bonds |
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Secondary structure of proteins |
Consists of regions of ordered structures taken up by the protein chaine Ie. Alpha helix Beta pleated sheet |
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Alpha helix |
Results from coilin of the protein chain, such that the peptide bond making the backbone , form hydrogen bonds these bonds are directed along the axis of the helix, the residues of the helix stick out at right angles from the helix stabilizing the structure. |
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Beta pleated sheet |
Layering of protein chains, one on top of the other ,here to the structure is held by hydrogen bonds between peptide links |
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Tertiary structure of proteins |
Overall 3D shape of a protein, obtained by the protein structure folding upon itself,inwich these amino acid residues interact with each other, repulsion and attraction to form a most stable conformation |
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The forces that control the 3D shape of tertiary structure? |
Covalent Ionic Hydrogen van Der waals Forces |
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Quatenary structure of proteins |
Confined to those proteins, which are a combination of a number of protein sub units |
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How do catalysts affect the rate of the rxn without affecting equilibrium |
They decrease activation energy of a reaction |
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Michaelis constant |
The substrate [ ] at which the rate of conversion is half of Vmax |
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Vmax in Michael menten eq? |
Maximum rate of conversion |
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A small Km indicates?
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Small km= high substrate affinity |
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Substrate witsh smaller km will? |
Approach vmax more quick |
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The product of catalyst rate constant and the concentration of the enzyme |
Vmax |
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Ways in which catalysts lower activation energy |
provide a reaction surface bring the reactants together pposition the reactants correctly so that they easily retain there transition state Catalysts weaken bonds Catalysts may participate in the mechanism. |
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Active site of an enzyme? |
Has 3D shape Has to be near the surface of the enzymes for the substrate to reach it, the site could be a groove, hollow or a tunnel allowing the substrate to sink into the enzyme. |
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Amino acids in the active sites are crucial to the enzymes function, the 2 basic roles of these amino acids are? |
Binding- The amino acid residue is involved in binding the substrate to the active site Catalytic- The amino acid is involved in the mechanism of the reaction. |
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The forces which bind a substrate to an active site are? |
Ionic Hydrogen Van Der waals |
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Competitive inhibition |
Exogenous molecule binds to the active site of the enzyme, blocking access of the endogenous substrate, thus preventing reaction from occuring. |
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Competitive inhibition can be overcome by |
Increasing level of natural substrate. |
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Non competitive( irreversible) inhibition |
Binds irreversiblely to the active site of an enzyme, increasing the natural substrate [ ] will not displace inhibitor |
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Non competitive reversible(Alosteric) Inhibitors. |
Bind to another site of the enzyme(not acive site) causes conformational change, in enzyme action site, so that substrate binding no longer occurs |
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Regulation of enzymes |
Generally product controls own synthesis by inhibiting the first enzyme in the metabolic pathway, the product binds to the alosteric site and not the active site |
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Enzyme catalyse reactions by providing the following |
Binding reactions Acid base catalysis Nucleophilic group |
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Binding interactions |
As enzyme changes its shape to maximize bonding interactions, the same thing happens to the substrate, bonds may get stretched and weakend, consequently forcing the substrate into the ideal conformation(transition state) for the reaction to follow |
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Acid/base catalysis |
Some amino acids in the active site that can serve as proton donors and or acceptors during the catalytic pathway |
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Nucleophilic groups in enzyme catalysis |
Serine,glutamate, aspartate and cysteine are common inhabitants of active sites, these amino acids have nucleophilic residues OH or SH which are able to participate in the reaction mechanism. |
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Medicinal uses of enzyme inhibitors rationale? |
If enzyme is responsible for growth, or biochemical pathway responsible for growth, inhibition of such enzyme causes death of the microrganism |
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Oxidorectase function? |
Enzymes that catalyse oxidation and reduction processes |
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Transferase function |
Enzymes that catalyse group transfer reactions |
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Hydrolases |
Enzymes that catalyse hydrolysis reactions |
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Lyases function? |
Enzymes that catalyse addition/Removal of groups |
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Isomerases function? |
Enzymes that catalyse isomerization |
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Ligases function? |
Enzymes that catalyse joining of 2 substrates |
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COX-1 function? |
Influences the housekeeping function of prostaglandins, which is production of bicarbonate in gastric mucous to prevent gastric tissue damage, maintenance of vascular tissue,nd proper kidney function |
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COX-2 function? |
Inducible enzyme, involved in inflammatory process, found on few cell types, which include, macrophages and other leukocytes, fibroblasts, and endothelial cells |
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NSAID'S? |
Non steroidal anti inflammatory drugs, tx of minor pain, and management of edema and tissue damage due to the arthritis, they also posses antipyretic function |
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NSAID'S uses? |
RA, OA, Acute gouty athritis, ankylosin spondylitis, dysmenohrea and tissue damage from Athritis |
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NSAID'S moa? |
Inhibit cycloxgenase enzymes |
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COX 1 selective inhibitors? |
Aspirin, ketoprofen, indomethacin, piroxicam, sulindac |
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Partial COX 2 selective inhibitors? |
Etodolac,nabumetone, meloxixam |
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Moa of celecoxib and rofecoxib |
Selective inhibition of Cox-2 |
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Antipyretic activity of Nsaids? |
Result from inhibition of prostaglandins E2 synthesis in the circumventricular organs and near the preoptic hypothalmic area,infections,tissue damage,malignancies etc, enhance the formation of cytokines that increase PGE2, triggers the hypothalamus to promote increase in heat generation and decrease in heat loss |