Unit 6 Flashcards by Dani Russell

reactants/substrates are ___ the arrow

before

How well did you know this?

Not at all

Perfectly

products are ___ the arrow

after

How well did you know this?

Not at all

Perfectly

A+B –> C+D

A+B are the ____/____

reactants/substrates

How well did you know this?

Not at all

Perfectly

A+B –> C+D

C+D are the ____

products

How well did you know this?

Not at all

Perfectly

A+B –> [AB] –> C+D

[AB] is the ___

intermediate

How well did you know this?

Not at all

Perfectly

the intermediate is not _____

isolatable

How well did you know this?

Not at all

Perfectly

–> means that the reaction is ____

irreversible

How well did you know this?

Not at all

Perfectly

means the reaction is ____

reversible

How well did you know this?

Not at all

Perfectly

rate of a rxn is determined by 5 things

[reactants]
temperature
pH
activation E and the energy barrier
[products]

How well did you know this?

Not at all

Perfectly

forward and reverse reactions occur ____, although the ____ reaction rates are different

simultaneously

initial

How well did you know this?

Not at all

Perfectly

both forward and reverse reactions are happening at the ____ same time, but at ___ rates

same

different

How well did you know this?

Not at all

Perfectly

____ _____: the concentration of the products cannot increase further

equilibrium state

How well did you know this?

Not at all

Perfectly

at equilibrium states, the forward and reverse reactions are still happening, but with no ___ __

net change

How well did you know this?

Not at all

Perfectly

2 formulas to calculate equilibrium constant Keq

[products]/[reactants]

k1(rate of forward reaction)/k-1(rate of backward reaction

How well did you know this?

Not at all

Perfectly

___ ___: when two reactants collide A+B. energy is released

activation energy

How well did you know this?

Not at all

Perfectly

activation energy must be ___ than energy barrier for the reaction to proceed

greater

How well did you know this?

Not at all

Perfectly

activation energy can be demarcated by 2 things

Ea or (delta)G*

How well did you know this?

Not at all

Perfectly

___ ___: the amount of energy required for the formation of products

energy barrier

How well did you know this?

Not at all

Perfectly

+(delta)G

low energy state–>high energy state

costs energy

How well did you know this?

Not at all

Perfectly

-(delta)G

high energy state–>low energy state

releases energy

How well did you know this?

Not at all

Perfectly

____ ___/____: how fast the products are formed

reaction rate

velocity (v)

How well did you know this?

Not at all

Perfectly

reaction rate/velocity: measured ____ in reaction

early

How well did you know this?

Not at all

Perfectly

(delta)G ultimately determines the ___ ____ of the reactants and products, but not the ___ ___

final concentration

reaction rate

How well did you know this?

Not at all

Perfectly

____: change in free energy from standard state, 1.0M concentrations of substrates and products to equilibrium

(delta)G0

How well did you know this?

Not at all

Perfectly

standard state: ___ degrees C ____K __atm

25 298 1

____ defines (delta)G0 at STP and pH 7.0

(delta)G0'

if free energy of products is lower than substrates, the signs of (delta)G0 and (delta)G0' will be ____

negative

if free energy of products is higher than substrates, the signs of (delta)G0 and (delta)G0' will be ____

positive

in ___ reactions, energy is lost

endergonic

in ___, energy is gained

exergonic

(-) delta G: reaction will occur ____ although the rate is ____

spontaneously | unknown

enzymes are ____: - ___ the rate of the reaction - are not ____ - bind to _____, lowering ___ - do not change ___

``` catalysts increase consumed substrates Ea Keq ```

enzymes are ____ - some are ___ (____) - many have ___ groups attached to apoprotein forming a ____ - if the prosthetic group is metal, it is a ___

``` proteins RNAs (ribozymes) prosthetic holoenzymes metalloenzyes ```

enzymes are __ and ___-____ - enzymes have optimal ___ and ____ - ___ or ___ that denature proteins denature enzyme activity

``` pH temperature-dependant enzymes temperatures chemicals factors ```

enzymes are ___ | - some are ___, some are ___

specific absolute group

some enzymes have ____ specificity, the ability to distinguish between L and D forms of amino acids or sugars

optical

____ ___: binds the reactants and facilitates the reaction

catalytic site

specificity is dictate by the 3D structure of the ___ ___ of the enzyme and the substrate --- requires a minimum of ____ point attachment

catalytic site | 3

___ ___: the substrate induces a conformational change in the catalytic site (lock and key)

induced fit

enzymes are saturable; a reaction mixture has a fixed amount of enzyme, so the reaction rate increases with [substrate] to a point, until all enzymes are _____

busy

enzymes are ___ or ___

inhibited | stimulated

_____: increase the rate of reaction

activators/stimulated

_____: decrease the rate of reaction

inhibitors

____ ___: act by competing with the natural metabolite for the active site of the enzyme therefore the are ___ ____

enzyme inhibitors | competitive inhibitors

___ ___: their effect can be overcome by addition of more natural substrate

reversible inhibitors

___ ___: eliminates enzymes function, Vmax is reduced

irreversible inhibitors

coenzymes are ___ ___ required for the catalytic actions of certain enzymes

secondary substrates

coenzymes can be ___ or ___

organic | inorganic

many coenzymes are ___ ___ (especially ___)

vitamin derivatives | B

some coenzymes are ___ ___ of enzymes

prosthetic groups

____: anything that help an enzyme do its function

coenzymes

___ ____ or ___: substances other than substrates which regulate and enzymes activity by binding to the ___ ___ of the enzyme

allosteric effectors or ligands | allosteric site

___ ___: can be catalytic site or another site of enzyme

allosteric site

binding of activator or inhibitor to the allosteric site changes the enzyme ____, especially the catalytic site, altering the reaction rate ____

conformation | exponentially

____: positive allosteric kinetics

acceleration

___: negative allosteric kinetics

deceleration

kinetic plot demonstrates a non linear ___ curve

kinetics assesses how ___ of an enzymatic reaction is affected by a host of factors (5 to name a few)

``` [substrate] coenzymes activators inhibitors pH temperature phase of the moon ```

experiments are done to obtain info on 3 things

specificity of an enzyme | mechanism of activation/inhibition

____ ____ ___: measures velocity of a reaction, with increasing substrate concentrations, keeping pH and temperature optimum

michaelis-menten equation

V max is...

max velocity of an experimental situation

Km =

the [substrate] that produces a velocity of 1/2 max | how strong affinity an enzyme has for its substrate

the ____ the Km, the ___ the affinity

lower --> higher | higher --> lower

lineweaver-burk (double reciprical) plot...

removes the uncertainty of the Vmax plateau of Michaelis-menten

michaelis-menten an lineweaver-burk are only good for ___-__ kinetics, bc of the additional substrate binding may alter the rate of the reaction

non-allosteric

trivial names of enzymes (2)

papain | chymotrypsin

hybrid name of enzymes

substrate + 'ase'

descriptive names of enzymes

substrate + description + ase

6 classifications of enzymes

``` oxidoreductase transferase hydrolase lyase isomerase ligase ```

____: redox reactions

oxidoreductase

___: transfer groups (other than H) between substrates

transferase

___: break substrates by addition of water

hydrolase

___: break sbstrates without water (leave double bonds)

lyase

____: convert isomers

isomerase

___: ligate with new covalent bonds

ligase

____: ligases that use ATP/GTP as energy sources

synthetase

____: ligases that use other energy (not GTP/ATP)

synthase

4 digit enzyme code: | - 1st number

class number

4 digit enzyme code: | - 2nd number

the first functional group of the substrate to be altered

4 digit enzyme code: | - 3rd number

the second functional group of the substrate to be altered

4 digit enzyme code: | - 4th number

denotes the particular enzyme

increase/decrease enzyme biosynthesis | - at the DNA/RNA level gene ___/____

induction | repression

REGULATION OF ENZYMES - SLIDE 27

aldkjf

____: two or more enzymes that catlyze the same biochemical reactions

isozymes