Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

M2M unit 1 > Bioenergetics and Enzymes > Flashcards

Bioenergetics and Enzymes Flashcards

(62 cards)

Start Studying
1
Q

what is keq that is at equilibrium?

A

1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Forms of kinetic energy

A

radiant energy from sun thermal (at certain temp to function optimally) Mechanical (mvmt of cells) Electrical (mvmt of charged particles down gradients)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Kcat

A

turnover number measures the number of substrate molecules turn over into product per enzyme molecule per second at saturation dictated by rate limiting step Vo=Kcat [Et][S]/([S]+ Km)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what is keq that favors reverse reaction

A

less than one

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Catalyst

A

increase the rate of a reaction (making or breaking bonds) without changing in the process

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

when k’eq is >1

A

delta G is negative and favors forward reaction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Km

A

(reaction of ES–> E+S * reaction of ES –> E+P)/(reaction of E+S–> ES) breakdown of reactants and products/ formation of ES not a binding constnat describes amount of substrate needed to reach 1/2 V Max

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Comparing Km to Kcat

A

Kcat/Km is the specificity contact ( rate constant for conversion of E+S to E+P) Comparison for efficiency of enzyme Enzymes with greater number have reached a higher catalytic proficiency.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what are the rearrangements of covalent bonds made in the active site?

A

general acid base catalysis covalent catalysis Metal ion catalysis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Uncompetitive inhibition

A

binding to ES in site other than active site reversible changes all parameters: lowers Vmax, Km and Kcat V = Vmax [S]/(Km +alpha’ [S]) alpha’ = 1+[inhibitor]/Ki (dissociation constant)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

proteolytic cleavage

A

enzyme is inactive when it is made, but once cleaved into small fragment to become activated trypsinogen –> trypsin Chymotrypsinogen pepsingon most enzymes in stomach and pancrease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

apoenzyme or apoprotein

A

protein part of the enzyme, inactive enzyme

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Change in reduction potential

A

E of electron acceptors (reduced) - E of electron donor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Enthalpy

A

(H) heat content for reaction system, energy in chemical bonds Negative is exothermic and favorable, positive is endothermic and unfavorable.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Covalent modification of enzymes

A

Phosphorylation, acetyl, adenylyl, methyl, amid, carboxyl, ubiquitation, ect. to change the conformation to change the function of the protein. due to intra or extra cellular signals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what is keq that favors a forward reaction

A

greater than one

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Competitive Inhibition

A

competes with substrate to active site reversible Kcat is unaffected Km increases as concentration of inhibitor increases V = Vmax [S]/(alphaKm + [S]) alpha = 1+[inhibitor]/Ki (dissociation constant)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Linweaver-Burk Plot

A

rearranged so that slope is Km/Vmax Competitive and mixed inhibition increases slope with increasing [I] non-competitive keeps slow the same with increasing [I]

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

prosthetic group

A

a coenzyme and cofactor that is tightly bound to enzyme

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Gibbs Free Energy

A

amount of energy capable of doing work during a reaction at contact temp and pressure. Not an indication of time dG = dH - TdS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Thermodynamically favorable reactions have a _____ delta G.

A

negative

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

how is ATP synthesized?

A

harnessing energy in gradient of H+ and electric potential across in cell membrane in mito provides energy for ATP synthase rotation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Ground state

A

starting point for either forward or reverse reaction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Coenzyme

A

complex of organic or metalloorganic molecules provide chemical groups for reaction and are used up ex. Pyruvate decarboxylase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
when k'eq is 1
delta G is zero and is in equilibrium
26
Redox
oxidation is loss of e- reduction is gain of e-
27
Rank in order of how much energy can be made from oxidation of carbon? Co2, lipid, carbohydrate
Lipid\>carb\> CO2
28
General acid base catalysis
amino acid side chains donate or accept protons to stabilize TS. with this, unstable intermediates break down rapidly to form reactants when proton transfer is show, only a small portion of intermediates are made, adding more proton donors and acceptors increase reaction rate.
29
Mixed inhibition where it is non-competative
rare only when alpha = alpha' Kcat and vmax are affect Km remains the same
30
what does lyase do?
addition of groups to double bond, formation of double bonds by removal of groups
31
how does ES complex form?
multiple weak non-covalent interacts provide specificity as well as catalysis enzymes are optimized to bind the transition state
32
Keq
Kf/kr = [c][d]/[a][b]
33
what bonds make the high energy bonds in ATP
phosphoanhydride where ADP and AMP are more stable than ATP nucleophilic attach can occur at 3 positions where they transfer a phosphoryl transfer
34
Entropy
S - qualitative exp for disorder Positive: disorder increases (favorable) negative : disorder degreses (unfavorable)
35
what do oxidoreductase enzymes do?
transer electrons
36
Cofactor
either one or more inorganic ions such as Fe2+, Mg2+, Mn2\_ and Zn2+ provide chemical groups and are not used up alcohol dehydrogenase
37
Velocity of enzymatic reaction is dependent on..
concentration of substrate low [sub] low velocity at saturation v = vmax
38
Log of a number less than one.
create a negative number!
39
Michaelis-Menton Equation
Vo = Vmax [Substrate]/([Substrate]+Km)
40
Forms of potential energy
Chemical bonds concentration gradients, electric fields redox pairs
41
Irreversible Inhibtion
combine with or destroy a functional group on enzyme that is essential for their activity Penicillin cymotrypsin
42
Allosteric Regulation of enzyme
Binding of another molecule, a regulator, to change conformation of enzyme to alter its function. Most feedback loops are regulated this way
43
Reduction potential
E readiness to accept electron positive value is ready to gain electrons; negative is ready to loose electrons
44
transition state theory
there is a single path for ground state to convert to the ground state of product and the TS is the highest energy state along this path. At TS, the reaction is equally likely to go forward or reverse
45
How do enzymes work?
provide a specific environment within with a given reaction can occur more frequently. Decreases the rate of a reaction and does not affect reaction equilibria. lowers the activation energy (transition state)
46
Mixed Inhibition
bind to both E and ES complex reversible Km, Vmax, and Kcat are affected. V = Vmax [S]/(alphaKm +alpha' [S])
47
Velocity of reaction
k{substrates]
48
where is Km on a graph of [s] vs veloicy
km is the x coordinate in which 1/2 vmax is reached
49
Delta G at equilibrium
-2.3RT log Keq or -1362 log Keq
50
Characteristics of an enzyme
1) make primarily of proteins with specific structures and active sites 2) some use cofactors or coenzymes 3) they are classified and named by what they do
51
how are unfavorable reactions cone
by coupling!
52
Electrical field in bioenergetics
increasing different in electrical potential increases delta G.
53
Bioenergetics of REDOX reaction
deltag = -nFdeltaE. n = number of electrons transfered F is faraday constant DeltaE is change in reduction potential in volts
54
holoenzyme
intact and activated complex of enzyme with coenzyme
55
High energy bonds
1)thioester bonds 2) phosphate bonds 2a) phsophoanhydride 2b) phosphoenolpyruvate 2c) phosphocreatine
56
how is gradient concentration related to bioenergetics
delta G is a function of the lob of [prod]/[reactants], generate more work by large gradient If you have more products than reactants, dG is positive If you have more reactants than products, dG is negative
57
how do enzymes lower activation energy?
Lock and key model is not a suitable model because TS has equally high energy Induced Fit: where enzyme is complimentary transition state to lower activation energy
58
Covalent catalysis
transient covalent bond forms between enzyme and substrate
59
Metal Ion Catalysis
bound metal ions help position substrate and can be driving force in REDOX reaction
60
when k'eq is \<1
delta G is positive and favors reverse reaction
61
what do hydrolases do?
hydrolysis
62
Ligase
formation of bonds with ATP cleavage

M2M unit 1 (6 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions