Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Biochemistry > enzyme regulation > Flashcards

enzyme regulation Flashcards

1
Q

substrate-level control acts on

A

a single reaction

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

feedback control targets

A

a different step in the pathway

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

activator ______ more products

A

promote

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

inhibitors _____ more products

A

prevent

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

strategies for enzyme regulation:

regulate the amount or availability (on/off switch)

A

temporal control of gene expression

protein degradation

enzyme compartmentalization

substrate availability

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

strategies for enzyme regulation:

regulate the activity of the enzyme (volume control)

A

isozymes and isoforms

covalent modifications

allostery

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

regulation of enzyme amount:

temporal control of gene expression (controlling gene expression of enzyme of interest)

A

regulation of chromatin remodeling

regulation of transcription

regulation of splicing and processing

regulation of transport out of nucleus

degradation of mRNA in cytosol

translational regulation

protein modifications

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

regulation of enzyme amount:

protein/enyzme degradation

A

intracellular digestion in lysosomes (low pH and acid hydrolases degrade in lysosome)

proteasome

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

regulation of availability:

enzyme compartmentalization

A

enzymes only acting in a specific location

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

regulation of availability:

substrate availability

A

availability of 2nd messengers in signaling cascades

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

regulation of enzyme activity:

isozymes and isoforms function to

A

catalyze the same reaction but with different efficiencies by mixing matching subunits: paralogs (gene duplication) and alternative splicing

also due to heterozygous alleles, monomer vs dimer/trimer etc, covalent modifications

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

lactate dehydrogenase (LDH) participates in

A

lactic acid fermentation pathway

pyruvate (end product from glycolysis) + NAHD + H+ –> NAD+ + lactic acid

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

LDH is a

A

tetramer (4 available isoform units)

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

LDH 1 > 2

A

heart attack

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

LDH 5 > 4

A

liver damage

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

regulation of enzyme activity:

reversible covalent modifications

A

creates nonproteinogenic amino acids by adding 1 or more functional groups to activate/inactivate the enzyme

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

reversible covalent modification:

lipids

A

myristoylation

farnesylation (farnesyl is an intermediate in cholesterol synthesis)

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

reversible covalent modification:

nucleic acids

A

ADP ribosylation

19
Q

reversible covalent modification:

proteins

A

ubiquitination

20
Q

reversible covalent modification:

carbohydrates

A

greatest source of diversity to the proteome

21
Q

how are carbohydrates linked

A

O- or N- linkages

22
Q

reversible covalent modification:

small molecules- gamma-carboxylation

A

gamma-carboxylation

carbon linkage

23
Q

reversible covalent modification:

small molecules - sulfation

A

sulfation (oxygen linkages)

24
Q

reversible covalent modification:

small molecules - acetylation and methylation

A

acetylation and methylation

used a lot in histone modifications

25
Q

methyl groups can go on either

A

arinine and lysine (nitrogen linkages)

26
Q

acetyl groups can go on

A

lysine (nitrogen linkages(

27
Q

reversible covalent modification:

small molecules - phosphorylation

A

oxygen linkages

28
Q

why is phosphorylation activating?

thermodynamics:

kinetics:

cell processes:

shape and charge complementarity:

A

thermodynamics: ATP hydrolysis (putting phosphate on) can drive unfavorable reactions- negative deltaG)
kinetics: physiological processes dictate reaction rate

cell processes: ATP amounts dictated by metabolism (energy charge); signal transduction amplification (catalytic turnover)

shape and charge complementarity: each phosphate adds (-2) charge and has potential to make 3 H-bonds

29
Q

kinases

A

adds phosphates

30
Q

phosphatases

A

remove phosphates

31
Q

the name of a kinase indicates

A

on which amino acid the phosphate will be added onto

e.g. serine kinases phosphorylate serine residues/amino acids

32
Q

regulation of enzyme activity:

irreversible covalent modifications

A

proteolytic activation

33
Q

zymogen

A

enzymes that need to be cleaved to become active

34
Q

examples of zymogens

A

proteases (digestive enzymes, collagenase, and caspases)

collagen

blood clotting factors

insulin/hormones

35
Q

regulation of enzyme activity:

allostery:

heteroallostery:

homoallostery:

A

heteroallostery: effector binds at the allosteric site
homoallostery: cooperativity

36
Q

example of allostery

A

ATCase in nucleotide metabolism

37
Q

binding of CTP perfers the

A

T/inactive state

inhibition of ATCase

38
Q

binding of ATP prefers the

A

R/active state

activation of ATCase

39
Q

LDH 1 =

A

H4

40
Q

LDH 2 =

A

H3M1

41
Q

LDH 3 =

A

H2M2

42
Q

LDH 4 =

A

H1M3

43
Q

LDH 5 =

A

M4

Biochemistry (32 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions