Lec 4 B Mechanism Of Enzyme Action Flashcards
What is the mechanism
of action of Enzymes
.enhance rate of rn. By lowering energy barrier
.transition state will take place when certain number of substrate mol possess enough energy
What is the transition state
is an unstable state in which the probability of making or breaking a chemical bond to form the product is very high. The transition state is the top of the energy barrier separating the reactants and products.
What is the energy of activation
Is the amount of energy required to bring all the molecules in 1 gram-mole of a substrate to the transition state.
What are the 6 groups of enzymes
1-oxidoreductases 2-transferases 3-hydrolases 4-lyases 5-isomerases 6-ligases
What are oxidoreductases
They cataylse oxidation reduction reactions
What are transferases
Catalyse transfer of C- or N- or P-
What are hydrolases
Catalyse cleavage of bonds by adding water
What are lyases
Catalyse cleavage of C-C , C-S and soms C-N bonds
What are isomrases
Catalyse rearrangement of of optical or geometric isomers
What are ligases
Catalyse formation of bonds between carbon and O or S and N coupled to hydrolsis of high energy phosphates
What are the clinical implactions of enzymes
Tissue plasminogen activators, are drugs that activate plasminogen to plasmin that degrades fibrin in blood clots. Thus given in case of acute myocardial infarction or ischemic stroke to lyse the thrombus.
What are common enzyme inhibtors in drug therapy
▪ Non-steroidal anti-inflammatory drugs, inhibit the cyclooxygenase enzyme (COX),
responsible for the formation of mediators of pain, fever and inflammation. Therefore, they are used as analgesic, antipyretic and anti-inflammatory. (Refer to drugs combating acute inflammation).
▪ Statins, are drugs that inhibit the enzyme responsible for synthesis of cholesterol (HMG- CoA- reductase). Therefore are used in treatment of hypercholest- erolemia for cardiovascular protection in atherosclerotic heart disease.
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