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44 Cards in this Set
- Front
- Back
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Protein C
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Anti-coagulation protein
Activated form is Protein Ca. Activates fibrinylosis |
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What is Warfarin? It works by...
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Anti-coagulation medicine.
Inhibiting Vitamin K epoxide reductase -- the Reduction of Vitamin K (so that it can be used again in coagulation). |
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Warfarin blocks...
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regeneration of Vitamin K and blocks coagulation.
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Warfarin has shown to have variable effects among patients because....
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Of the variation in the genes for Cytochrome and Complex 1 of the Vitamin K epoxide reductase.
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Name the two pathways for coagulation...
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Intrinsic (Kininogen)
Extrinsic (trauma - tissue factor) |
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Which factor is common between intrinsic and extrinsic coagulation pathway?
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Factor X and Xa (and everything following that....Thrombin, Fibrinogen, XIIIa)
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Which factor is common to coagulation and anticoagulation pathways?
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Thrombin
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Name 4 things that impact k (rate of a reaction)?
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pH
Ion concentration Temp Activation energy (can be lowered with a catalyst) |
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V (reaction rate) =
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k[a][b] (A and B are substrates)
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What is a first order and a second order reaction?
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First order - One reactant
Second Order - two reactants |
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Rate of a reaction increases when...
As the substrate is consumed, the rate of reaction.... |
The concentraion of substrate increases.
Decreases. |
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What is Michaelis constant?
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It is only associated with rate constants.
Km is substrate concentration at which the velocity is half the maximum velocity. Km = (K-1 + K2)/K1 |
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When can a rxn be at Vmax?
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When the enzyme is saturated. (All of the enzyme is being used so the rate can not increase anymore, even if more substrate is available).
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What is dissociation constant
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[E][S]/[ES]
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What is "a measure of enzyme concentration for significant catalysis to occur"?
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Turnover number.
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What is "a meaasure of substrate concentration when half of Vmax is reached"?
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Km
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Define "enzymes"
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Biological chemicals that increase rate of chemial reactions.
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Catabolism
Anabolism |
Catabolism - Energy production. Fuel oxidation.
Anabolism - Energy consumption. Reduction process. |
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What is apoenzyme?
Wheat is haloenzyme? |
An enzyme without its cofactor is called apoenzyme.
An enzyme with a cofactor is called haloenzyme. |
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Vitamin E deficiency
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Inhibition of sperm production
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Vitamin K deficiency results in....
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Subdermal hemorrhaging (this vitamin helps with blood coagulation)
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What are the cleavate sites for following proteases?
Chymotrypsin Trypsin Thrombin Proteinase K |
Chymotrypsin - Aromatic residues on the carboxyl side of the bonds
Trypsin - Carboxyl side of Arg and Lys Thrombin - Between Arg and Gly Proteinase K - Lacks residue specificity. |
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Describe the two models of enzyme-substrate complex?
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Lock and Key - Enzyme structure remains the same.
Induced Fit - Dynamic recognition. Enzyme changes its shape as the substrate binds to it. |
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What is a catylytic triad?
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Three potentially charged residues near one another in the interior of the enzyme.
Serine, Histidine and Aspergine. |
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What is the function of transglutamidase?
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Transglutamidase (Factor XIII) stabilizes soft clot between fibrin monomers and creates hard clot.
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What is "Proteinase Active Receptor"?
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Activated thrombin receptor.
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What is "von Willerband's factor"?
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It is a glycoprotein that helps platlets bind to activated thrombin receptor.
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What is the importance of gama-carboxyglutamate?
It is produced using.... |
It binds to phospholipid surface with the help of Ca2+.
This factor is produced using Vitamin K. |
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Protein C is a....
Activated by... Describe the cascade... |
Major factor in regulation of coagulation.
Activated when Thrombin binds to thrombomodulin (thrombomodulin is on the surface of endothelium) Protein C >> Protein Ca >> blocks tPA inhibitor >> Active Plasmin increase (which digests fibrin clot) |
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What is the function of urokinase?
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It maintains Active plasmin levels in the plasma.
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What is tPA?
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tPA activates plasmin (part of fibrinolysis).
tPA inhibitor is blocked by Protein Ca. |
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What Protein S?
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Protein S is derived from Protein Ca.
It is a cofactor that helps in anticoagulation by blocking Va and VIIIa. |
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How does heparin impact coagulation?
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Heparin binds to Antithrombin and causes Xa to bind to antithrombin.
Xa bound to antithrombin is in inactive form and hence, this stops clotting. |
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What is Km?
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Km is a measure of SUBSTRATE concentration required for significant catalysis to occur.
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What is turnover number?
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Applies when the enzyme is completely saturated by substrate.
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What is an isozyme?
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An enzyme that catalyes the same chemical reaction (this enzyme comes from different genes and has different amino acid sequence).
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Give two examples of enzymes that have isoforms.
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LDH (heart and myocyte)
Creatinine Kinase |
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What is negative cooperativity?
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Negative cooperativity - When binding of the substrate to an enzyme decreases enzyme activity.
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Prothrombin is activated by...
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Va, Xa and Phospholipids
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Factor X is activated by...
Intrinsic pathway Extrinsic pathway |
Intrinsic - IXa, VIIIa
Extrinsic - VIIa and TF |
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Soft clot is stabilized by...
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Transglutamidase....covalent bonds.
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Transglutamidase is responsible for
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stabilizing the soft clot and forming hard fibrin clot (factor XIIIa)
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Why does glutamate acid need to be carboxylated during coagulation?
What assists in this carboxylation? |
Negatively charged carboxylated groups bind to the membrane phospholipids. (Membrane is also negatively charged, so Ca+2 is required for this interaction).
Vitamin K is vital in the carboxylation of Glutamate acid. |
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How does Warfarin work?
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Anticoagulation medication
Warfarin blocks reduction of Vitamin K epoxide. This inhibits formation of gama-glutamidase and blood clotting. |
