enzymes that catalyze oxidation-reduction reactions
oxidoreductases
enzymes that catalyze transfer of C-, N- or P- containing groups
transferases
enzymes that catalyze cleavage of bonds by addition of water
Hydrolases
enzymes that catalyze cleavage of C-C, C-S and certain C-N bonds
lyases
enzymes that catalyze racemization of optical or geometric isomers
isomerases
enzymes that catalyze formation of bonds between carbon and O, S, N coupled to hydrolysis of high-energy phosphates
Ligases
Michaelis Menton Equation
True/False: alloesteric enzymes follow MM kinetics
FALSE
What does a low Km mean
don’t need a lot of substrate to get half of maximum therefore there is a higher affinity of the enzyme for the substrate
strong substrate binding
What does a high Km mean
need a lot of substrate to get half of maximum therefore there is a lower affinity of the enzyme for the substrate
weak substrate binding
3 assumptions associated with MM
[S]>>>>[E]
[ES] is relatively constant
initial reaction velocities are measure
3 problems with using non-initial velocity
1.Enzyme might undergo random hydrolysis or denaturation
2.Product accumulation might exert negative feedback (product inhibition)—will turn off the enzyme
3.As substrate is being depleted, enzyme spends more time diffusing through solution before it encounters substrate molecule
Km= ?/?
Kd (dissociation of ES)/ Ka (association of ES)
at very low substrate connections the velocity of the reaction is
First order
proportional to [S]
Very high: constant and independent of [S]– zero order
at very hight substrate concentrations the velocity of the reaction is
Zero order
Constant and independent of [S]
What is the LWB plot equation
what does the y-intercept on LWB represent
1/vmax
what does the x-intercept on LWB represent
-1/Km
what is the scientific name for aspirin?
Acetylsalicylic acid
enzyme involved in forming certain inflammatory molecules
(example: inhibited by aspirin--therefore aspirin is an anti inflammatory)
cyclooxygenase
--irreversible
penicillin covalently (irreversibly) attaches to a serine reside in _______ enzyme which is responsible for the formation of cross-links int the cell wall of bacteria
transpeptidase
Competitive inhibitors ____ Km and ____ Vmax
increase (lower the affinity of enzyme for substrate)
do not effect
Non-competitive inhibitors ____ Km and ____ Vmax
do not effect
decrease
True/False: increasing the levels of substrate has no effect on non-competitive inhibition
TRUE
The inhibitor allupurinol targets which enzyme and has what effect or application?
xanthine oxidase
drug for treatment of gout
what is an inhibitor that targets thymidylate synthetase and its application is an anticancer drug (cause inhibiting nucleotide metabolism)
5-Fluorouracil
B-aminopropionitrile targets which enzyme?
lysly oxidase
KNOW THIS ENZYME HAS AN INHIBITOR DON'T GET TOO HUNG UP ON NAME OF INHIBITOR
methotrexate targets which enzyme and what is its application
dihyrofolate reductase
it is a cancer chemotherapy
Acyclovir is an ______ drug that targets _____ enzyme
anti viral
DNA polymerase
which inhibitor targets phosphodiesterase type 5 and is used for erectile dysfunction
sildenafil (viagra)
which inhibitor is used as a muscle relaxant and targets acetylcholinesterase?
succinylcholine
Reverse transcriptase inhibitors target which enzyme and what is their application
Reverse transcriptase
treatment of retroviruses (HIV)
enzyme that cleaves trypsinogen to form trypsin
enteropeptidase
which enzymes carry out phosphorylation
which enzymes carry out dephosphorylation
kinases
phosphatases
protein kinases use what to add P to the enzyme
ATP
phosphatases use what to remove the P from the enzyme
water
where would you find the enzyme acid phosphastase (2)
prostate, RBC
where would you find the enzyme alanine aminotransferase (3)
liver, heart, skeletal muscle
where would you find the enzyme alkaline phosphatase (2)
liver, bone
A number of B vitamins are precursors of coenzymes. These include the following B vitamins (7):
Thiamine
Niacin
Riboflavin
Pyridoxine
Folic acid
Pantothenic acid
Cyanocobalamin
enzyme that converts ethanol to acetylaldehyde
alcohol dehydrogenase
enzyme that converts acetalaldehyde to acetic acid
acetalaldehyde dehydrogenase
acetalaldehyde dehydrogenase is inhibited by ____ which increases the hangover sensation and is good for alcoholics
Disulfiram (antabuse)
what are alcohol dehydrogenase and acetylaldehyde dehydrogenase also used for other than alcohol metabolism
the breakdown of methanol (wood alcohol) to formic acid
why can ethanol be a remedy for methanol poisoning and ethylene glycol (anti-freeze) poisoning
it competitively inhibits the alcohol dehydrogenase enzyme--binds better to the enzyme than methanol and ethlyene glycol
the breakdown of ethylene glycol (antifreeze) is
alcohol dehydrogenase
this enzyme is not specific as it can break down this, ethanol and methanol
what is an abzyme
an antibody that functions catalytically
True/False: Km does not vary with the amount of enzyme
TRUE
it is a measure of the stability of the ES complex generally measuring the affinity of the enzyme for the substrate
what enzymes are therapeutically used for Pulmonary embolism, myocardial infarction
streptokinase
tissue plasminogen activator
what enzyme is therapeutically used for
Gaucher Disease (lysosomal disease)
Glucocerebrosidase
does lysyl oxidase have an inhibitor?
YES
it is b-aminoproionitrile (don't really need to know this tho)