Enzymes Flashcards
Abnormal large amount of enzymes in serum are used clinically as evidence of?
Organ damage
When bind tightly to the enzyme, the coenzyme is called
Prosthetic group
Water free cavity
Active site
Inactive enzyme precursor. Coagulation factors and digestive enzyme
Proenzyme or zymogen
Where the substrates bind and undergo a chemical reaction
Active site
Active substance formed by a combination of a coenzymes and an apoenzymes
Holoenzyme
Binds regulatory molecules
Allosteric site
Substance acted upon enzyme, specific for each enzyme
Substrates
Promote change in shape
Allosteric site
Specific biologic proteins that catalyze biochemical reactions without altering the equilibrium point of the reaction or being consumed or changed in composition
Enzymes
Represents the subclass to which the enzyme is assigned
Second and third digits
Serial number that is specific to each enzyme in a subclass
Final and fourth number
Helper molecules, nonprotein substance added in the enzyme substance complex to manifest the enzyme activity
Cofactors
Places the enzyme in its classification
First digit
Catalyze the hydrolysis of various bonds.
Splitting of a bond by addition of water
Hydrolases
Catalyze the interconversion of geometric, optical or positional isomers
Isomerase
Protein portion of enzyme, subject to denaturation, in enzyme losses activity
Apoenzyme
Physical binding of a substrate to the active site of an enzyme
ES complex
Catalyze an oxidation reduction reaction between two substrates
Oxidoreductase
Catalyze the joining of two substrate molecules, coupled with breaking of the pyrophosphate bond in adenosine triphosphate or a similar compound
Ligases
Enzymes combined with only one substrate and catalyzes only one reaction
Absolute specificity
They combine with all the substrates containing a particular chemical group
Group specificity
Reaction rate is directly proportional to substrate concentration
First order kinetics
Excess energy
The energy required to raise all molecules in 1mol of a compound at a certain temperature to the transition state at the peak of energy barrier
Activation energy
Specific to chemical bonds
Bond specificity
pH range wherein most physiologic reactions occur
7-8
Enzymes that predominantly combine with only one optical isomer of certain compound
Stereoisomeric specificity
Only a fixed number of substrates is converted to product per second
Zero order kinetics
Inactivation temperature of enzymes
60-65C
Nonprotein entities that must bind to particular enzymes before a reaction occurs
Cofactor
Optimal pH is controlled by means of appropriate
Buffer solution
Catalyze the transfer of a group other than hydrogen from one substrate to another
Transferase
Incubation temperature
+/-1C
For every 10C increase in temperature, there will be two fold increase in enzymatic activity
Temperature coefficient
Alter the spatial configuration of the enzyme for proper substrate binding, linking substrate to the enzyme or coenzyme
Activators
Binds an enzyme at a place other than the active site but instead prevent all enzymatic activity by binding to all allosteric site located elsewhere on the enzyme
Noncompetitive inhibitor
Catalyze the removal of groups from substrates without hydrolysis.
The product contains double bonds
Lyases
Second substrate
Coenzyme
Physically bind to the active site of an enzyme and compete with the substrate for the active site
Competitive inhibitor
Appear in the serum following cellular injury
Enzymes
Enzymes are measured in terms of?
Change in:
Substrate concentration
Product concentration
Coenzyme concentration
Results in permanent loss or enzymatic activity
Permanent binding
Results from a change in the shape of the active site when an inhibitor binds to an allosteric site
Allosteric inhibitor
Reaction rate depends only on enzyme concentration
Zero order kinetics
Enzymes are active at what temperatures?
25, 30, and 37C
Binds to the enzyme substrate complex. Does not yield products
Uncompetitive inhibitor
Theory wherein based on the shape of the key must fit into the lock
Lock and key theory
The reactants are combined, the reaction proceeds for designated time, the reaction stopped and a measurement of the amount of reaction that has occurred is made
Fixed time method
An increase in the concentration of substrate molecules will result to the increase in the likelihood of the active site that will be filled by the substrates instead of inhibitors
Reversible competition
An organic factor
Coenzyme
Based on the substrate binding to the active site of the enzyme.
Induced fit theory
Coenzyme frequently measured in the lab
NADH
Multiple measurements of the absorbance changed are made during the reaction
Continuous monitoring
Results when binding of an activator molecule to an allosteric site caused a change in the active site that makes it capable a binding a substrate
Excitory allosteric inhibitor
Enzyme concentration are always performed in?
Zero order kinetics
Similar enzymatic activity but differ in physical, biochemical and immunologic characteristics
Isoenzyme
Increasing its concentration will increase the velocity of an enzymatic reaction.
Essential for complete enzymatic activity
Coenzyme
The reaction is assumed to be linear over the reaction time
Fixed time method
As the enzyme binds to the substrate the shape of the active site conforms precisely to the shape of the substrate
Induced fit
Convenient method of an enzyme quantitation is measurement of its?
Catalytic activity
Optimum temperature of enzymatic activity
37C
More advantageous over fixed time method because the linearity of the reaction may be more adequately verified
Continuous monitoring
Acid phosphatase is seen in
Prostatic carcinoma
Alanine transferase is seen in
Hepatic disorder
Alkaline phosphatase is seen in
Hepatic disorder
Bone disorder
GGT in
Hepatic disorder
Lactate dehydrogenase
Myocardial infarction
Hepatic disorder
Hemolysis
Carcinoma
Amylase in
Acute pancreatitis
Lipase in
Acute pancreatitis
Trypsin in
Acute pancreatitis
Aspartate aminotransferase
Myocardial infarction
Hepatic disorder
Skeletal muscle disorder
Myocardial infarction increase in what enzyme?
AST
CK
LD
Hepatic disorder increase in
ALT ALP AST GGT LD
Chymotrypsin in
Chronic pancreatitis insufficiency
Skeletal muscle disorder increase in
AST
CK
Acute pancreatitis increase in
AMY
LPS
Trypsin
Chronic pancreatitis insufficiency increase in?
Chymotrypsin
Elastase 1
Generally associated with ATP regeneration in contractile or transport system
CK
CK major sources
Skeletal, muscle and brain tissue
Predominant function occurs in muscle cells, where it is involved in the storage of high energy creatine phosphate
CK
CK level is considered as sensitive indicator of?
Acute myocardial infarction
Duchenne type
CK is a dimeric molecule with small molecular size composed of pair of two different monomers called
M and B
This is known to increase CK <5x URL
Intramuscular injection
The dominant isoenzyme of CK found in brain, intestine and smooth muscle
CK-BB
Highest concentration of CK BB is seen in
CNS
GIT
Uterus during pregnancy
Useful tumor associated marker
CK BB
CK isoenzyme that Migrate fastest
CK BB
CK-1
Serves as buffer
Component of CK reagent
Imidazole
Creatine kinase in
Myocardial infarction
Skeletal muscle disorder
The only tissue from which CK MB enters the serum in significant quantities
Myocardium
Measures decrease in absorbance at 340nm with optimum pH oh 9. CK method
Tanser-Gilbarg assay
Forward or direct method
