Bio Test 2 Enzymes

Front 1

fermentation

Back 1

organic compounds-----fermentation products

organic compounds - glucose 6-C, electron and H+ flow is interal via redox rxns

fermentation (ethanol, lactate) products contain much of orig E of glucose
---C in glucose in products too
---electrons/H+s not gone, still in products

Front 2

aerobic respiration

Back 2

organic compounds---CO2

org compounds (glucose)
---elec/H+ flow is external via redox rxns to O via ETS

product is CO2 and E in glucose stored in reduced molecules (NADH and FADH2)

Front 3

anaerobic respiration

Back 3

organic compounds---CO2

org compounds-
(glucose, cellulose)
--electron/H+ flow is external via redox rxns
NO2-->NO3-->NH4
SO-->H2S
CO-->CH4

product is CO2 and the E is reduced mol's NH4, H2S, CH4

swamp, flames

bacteria live w/o much O

look @ q's

Front 4

axioms of enzymology

Back 4

1. enzymes are proteins
2. enzymes are macrmols
3. enzymes made from a.acids joined by peptide bonds
4. amino acids are of the l-config
5. props -->ed by sequence of a.acids
6. orderly structures (crystallized, or still retain activity)
7. catalytic action carried out at active site
8. enzymes form an enzyme substrate complex w/ their substrates
9. rxn rate of enzyme catalyzed rxn depends on [substrate]
10. rates of conversion of the enzyme substrate complex [ES] to product is very FAST (turnover number high)

Front 5

axioms of enzymology: 1. enzymes are proteins

Back 5

enzymes are proteins, (a few RNA mol's that act similar to enzymes have been found)

Front 6

axioms of enzymology: the active site

Back 6

where enzyme acts w/ substrate

a geometrically discrete region of the enzyme

ex: hemoglobin w/ oxygen

catalytic action carried out within an active site

Front 7

axioms of enzymology: turnover number

Back 7

how much substrate -->ed to product per enzyme per active site per unit of time

rates of conversion of the enzyme substrate complex [ES] to product is very FAST (turnover number high)

Front 8

___ and ___ affect active site

Back 8

pH & temp

at higher temps, rate decreases quickly

pH: pepsin works well low pH
temp: trypsin high pH

Front 9

substrate level phosphorylation

Back 9

ATP made on spot @ active site

substrate gives Pi to ATP from ADP

enough E released to ADP --> ATP

Front 10

an ___ exists between substrate --> product

Back 10

energy barrier

Front 11

energy barrier is a ___ that ___ must overcome in order to be raised to a higher E level

Back 11

energy barrier is a ENERGETIC HILL that the SUBSTRATE must overcome in order to be raised to a higher E level

Front 12

activation E

Back 12

'fleeting molecular moment'

enzymes decrease E of activation to start the rxn

Front 13

enzymes

Back 13

--proteins, regulate metabolism

--specific

--organic

--large macromol's w/ small active sites

don't change equilib of rxn

speed up rxns by moving substrates, adding charges to substrates, or by inducing strain on substrate

Front 14

transition state

Back 14

top of 'energetic hill' E barrier

reactant (A) raised to higher unstable E level and will --> forward P or decay bk to A

diff b/t ground state and transition state = free E of activatoin

Front 15

rxn rates caused by

Back 15

increasing temp, increasing # mol's

Front 16

activation E can be lowered by

Back 16

adding a catalyst

catalysts lowering activation energies

Front 17

in living systems, the ___ is an enzyme

Back 17

in living systems, the catalyst is an enzyme

Front 18

michaeli menten kinetics equation

Back 18

E+S <--> ES ---> E +P

E enzyme
S substrate
ES enzyme substrate complex
P products

Front 19

M&M kinetics factors of the equation

Back 19

depends on

phy factors:
pH, temp, pressure

chem factors: [S] and [E] which --> [ES] --> [P] and [E]

Front 20

product is a ___

Back 20

product is a rate

Front 21

use ___ to compare enzymes

Back 21

use MAX VELOCITY to compare enzymes

MAX amt of substrates per unit of volume


since [E] not limiting the rxn, as amt of [S] increases, so does velocity of the rxn

Front 22

rate of enzymatic rxn if amt of [E] NOT limiting and substrate is increased

Back 22

[S] v. V

levels off

Front 23

influence of phy factors pH and temp on enzymes

Back 23

as [S] increases, so does volume

enzyme starts converting -->

no limit --> keeps going up but not realistic b/c no space! not unlimtied supply of enzymes

there is a fixed amt

Front 24

rate of enzymatic rxn if the amt of enzyme is limiting and substrate is increased

Back 24

eventually will stop increasing -->


maximum velocity: max amt of substrate created

Front 25

max velocity

Back 25

use max velocity to compare enzymes

max amt of substrate created

enzyme limiting and substrate increased --> increased velocity

Front 26

vmax
----
2

Back 26

compare enzymatic rxns

since may [S] produce Vmax, proposed this

1 [substrate[ --> 1/2VMax

Km - [S] that -->es 1/2 max vel

Front 27

Km

Back 27

compares how single enzyme may react to 2 diff substrates

[S] that --> Vmax/2

S1 and S2 diff substrates, produce same max veloc Vmax....takes much more of S2 to reach Vmax than S1

S1 gets faster, takes less to get to Vmax

no diff in how enzyme rxs

Km1 lower than Km2 --> enz higher affinity for sub1 than sub2

E+S1 --> >er ES complex than E+S2

Front 28

Km=[E][S]
----------
[ES]

Back 28

1. if [ES] is large then Km is small

small Km=good affinity of enzyme

close to 0--> enz/sub high affinity

2. if [ES] small then Km large
large Km=less affinity of enz for substrate

Front 29

almost impossible to measure [ES] so --> formula

Back 29

v=Vmax [S]
--------
Km + [S]

michaelis Menten Equation

way of relating velocity of rxn to [substrate]

Front 30

michaelis menten kinetics and equation are true if following conditions met

Back 30

1. enzymatic rxns go thru an ES complex
2. rate of conversion of [ES]--> [P] depends on rate of ES formed

3. [S] is greater --> no need to correct for S in ES complex

4. velocity proportional to [ES] complex

5. vmax is proportional to the amt of enzyme participating in the rxn
(a) if [S] < Km, v depends on [S]
(b) if [S] sig >er than Km, velocity is Vmax
(c) when [S]=Km, velcotiy is Vmax/2 (equilib)
(d) if [S] increased, other conditions constantm, velocity increase to Vmax and no more
(e) at Vmax, an increase in [S] will have no influence on velocity

Front 31

active site

Back 31

specific substrate binding are of enzyme

where enzyme's shape comes from

Front 32

enzyme-substrate complex (ES)

Back 32

once enzyme bound to active site

Front 33

inhibitors

Back 33

bind to enzymes and slow rate of rxn

--irreversible inhibition
--reversible inhibition
-~~~~ non/competitive ~~~~~~inhibitors

Front 34

irreversible inhibition

Back 34

inhibitors covalently bond to an enzyme and destroy its active site

Front 35

reversible inhibition

Back 35

inhibitgors bind to/alter the active site but its changeable

dpeends on [] of inhibitor and substrate

Front 36

competitive inhibitors

Back 36

type of reversibile inhibition

compete with substrate for the active site

Front 37

noncompetitive inhibitors

Back 37

irreversibile inhibiton

bind elsehwere but alter active site so that substrate can't bind/ rate of binding decreased

Front 38

M&M discovered what?

Back 38

[ES] complex

Front 39

two things that occur @ transition site

Back 39

1. can go bk down to A, becomes the same [S]

2. or can --> product

Front 40

vmax
----
2

describes what?

Back 40

compares how [S] rxs w/ the enzyme

Front 41

Km small --

Km large---

Back 41

Km small -- [ES]/affinity big



Km LARGE -- affinity SMALL/[ES] small

Front 42

vmax value know as enzymes _____ value

Back 42

constant, fixed value