Intro to Enzymes

enzymes

biological catalyst — hasten/fasten the chemical reaction

No

yes or no: does enzymes can be consumed during the reaction

No

yes or no: does enzyme undergo a chemical change

it catalyze or interact with the substrate to facilitate chemical reaction

what is the main action or function of an enzyme

cells and tissues

where do enzymes usually found

yes, but in low levels

are they present in the circulation

enzymology

what do you call the study of enzymes

NO

yes of no: do enzyme undergo chage

enzyme and substrate

what is the basic requirement of the enzyme-substrate complex

No reaction will occur

does any reaction happen when we only have enzyme/substrate ALONE

products and enzyme

what are produced with the enzyme-substrate complex

yes

yes or no: only substrate can be consumed

true, but in a longer time

true or false: we can still form a product without an enzyme

• absolute

• group

• linkage

what are the 3 types of enzyme specificity

absolute

this type of specificoty can Catalyze one type of reaction for a single substrate

group

this type of specificity can Catalyze one type of reaction for all similar substrates

group

a type of specificity that looks for a specific functional group

linkage

this type of specificity, can Catalyze one type of reaction for a specific type of bond

michaelis-menten theory

a theory that Compares of energy required for a chemical reaction to occur with an enzyme vs. without an enzyme

lock and key model

this model is the binding of enzyme to a substrate to form a complex which will yield a product

emil fisher

lock and key model is discovered by

active site

this is where a substrate bind to an enzyme

allosteric site

this site is where the activators and inhibitors bind

No

does substrate bind to the allosteric site, yes or no

activators

it promotes the binding of the enzyme to the substrate

inhibitors

it prevents/inhibits the binding of enzyme to the substrate

false

true or false; enzyme and active site has the same measurements

Allopurinol

Bonus Qs: What is the inhibitor Xanthine Oxidase

False

true or false; all substrate has an +ase suffix

1st - class

2nd - subclass

3rd & 4th - serial number

in the enzyme commission nomenclature, what does the 1st, 2nd,3rd & 4th digits stand for

• oxidoreductases

• transferases

• hydrolases

• lyases

• isomerases

• ligases

list down the classification of enzymes (in order)

enzymatic reaction

can occur in both ways. there is a forward and reverse reaction, thats why the arrow points both ways

oxidoreductases

all enzymes in this class can perform oxidation and reduction forward and reverse

oxidation

this is a reaction where it is the removal of H ion and the acceptance of O ions

reduction

this reaction is the acceptance of H ions and the removal of O ions

lactate

in LDH what is the substrate in the forward reaction

pyruvate

in the reverse reaction of LDH, what is the substrate

transferase

it is the transfer of functional groups other than hydrogen from one substrate to another

glutamate

in the reaction of AST the NH2 is transfered from aspartate to a-ketoglutarate and it will become_______

oxaloacetate

when you remove the NH2 of the aspartate is will become_______

hydrolases

• hydrolysis of various bonds

• addition of water to a bond resulting in bond breakage (loss of substrate)

diacylglycerol with 1 free fatty acid

lipase with water will breakdown TAG and become ______

lyases

catalyze the removal of groups from substrates w/out hydrolysis or oxidation; the products contains double bonds or a ring

lyases

breaksdown big molecule with NO WATER involved

lyases

this classification of enzyme produce a product that always contain either a double-bond or a ring

double bond or a ring

what should be the product produce by the enzyme classification Lyases

isomerases

it rearrange the functional group within a molecule and catalyze the conversion of one isomer into another

ligases

• catalyzes the joining of two large molecules by forming a new chemical bond

• accompanied by an ATP-ADP interconversion

substrate

• specific

• acted upon by the enzyme

• it is converted to products

isoform

when enzyme is subjected to posttranslational modification with a functional group added to an amino acid

cofactor

• a non-protein molecule

• helper of enzyme

• promotes enzymatic attachment to substrate

• some enzyme requires with it and some do not

apoenzyme

• a polypeptide/protein portion

• inactive enzyme

• enzyme that requires a cofactor but has not met a cofactor

holoenzyme

• a complex of apoenzyme + coenzyme

• has met a cofactor

enzyme substrate complex

a complex of apoenzyme + coenzyme + substrate

• activators

• coenzymes

what are the two types of cofactor

prosthetic groups

a type of cofactor that tightly bound

• metal ions (activator) or organic molecule

what are the example of prosthetic groups

prosthetic groups

change to the configuration of the enzyme. link substrate to the enzyme or coenzyme

coenzymes

a type of cofactor that is loosely bound

coenzymes

it is also known as the second substrate for enzyme reaction

• heme

• flavina denine dinucleotide (fad)

examples of cofactor; prosthetic groups

• flavin mononucleotide (FMN)

• thiamine pyrophosphate (TPP)

• nicotinamide adenine dinucleotide (NAD)

• lipoic acid

examples of cofactor; coenzymes

• Zn2

• Cu2

• Mg2

examples of cofactor; metal ions

proenzyme

an enzyme precursor/immature enzyme that is also known as zymogen

true

true or false; not all enzyme have proenzyme

vmax / maximum velocity

this part of the michaelis-menten theory where the reaction stops because all enzymes are saturated already

lineweaver-burk plot

it is a double-reciprocal plot of the michaelis-menten constant which yields a straight line

• substrate conc

• enzymatic conc

• pH

• temperature

• cofactors

• activators

• inhibitors

what are the factors that influence enzymatic reactions

first-order reaction

• a rate exactly proportional to the concentration of ONE REACTANT

• when the reaction rate is directly proportional to the substrate conc.

second-order reaction

the rate is proportional to the product of the conc. of two reactants / square of the conc. of one reactant

relationship of substrate conc. and velocity is directly proportional

what is the similarities of the 1st and 2nd order reaction

zero-order reaction

this reaction is when the substrate conc. is high enough to saturate all available enzymes

7-8 pH

what is the pH of most enzymes

true

true or false; change in pH may denature the enzymes

buffers

how to ensure desired pH in reagent

37c

what is the optimal temperature for enzymes

40-50c

the enzymes will be denatured in this temperature

4-10c

the enzymes will be inactivated in this temperature

25, 30, 37c

what are the assay temperature

cofactors

a non protein entities that must bind to particular enzymes before a reaction occurs

activators

• can make a proper substrate binding

• links substrate to the enzyme or coenzyme

• undergo oxidation or reduction

inhibitors

this interfere with the enzyme reaction

• competitive

• noncompetitive

• uncompetitive

what are the 3 types of inhibitors

competitive inhibition

the inhibitor binds to the active site

noncompetitive inhibition

• the inhibitor will bind to the allosteric site

• changes the shape of the active site making it unable for the substrate to bind

uncompetitive inhibition

• the inhibitor will bind to the enzyme-substrate complex

• the inhibitor is considered smart because it waits for the enzyme and substrate to bind first

lock and key theory

the structure of the substrate is complementary to the size and appearance of the active site

induced fit theory

this theory says that if a substrate comes close to its target enzyme, the active site will change its structure to accommodate the substrate

coupled-enzyme assay

an enzymatic assay that coupling the activity of he enzyme being tested to another, more easily detectable, enzyme

fixed-time method

• an enzymatic reactant that are combined, reaction proceeds for a designated time, reaction is stopped

• measurement is made of the amount of reaction that has occured

continuous-monitoring method

multiple measurements of absorbance change