Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

VP Cell Physiology > Test 2 Enzymes > Flashcards

Test 2 Enzymes Flashcards

(46 cards)

Start Studying
1
Q

What are the (3) main processes that use enzymes?

A

Fermentations, biotransformations, and pharmaceutical industry.

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

What is an enzyme?

A

Protein catalyst that binds to other molecules and increases the rate of reactions by lowering activation energy without being changed themselves. Direct substrate molecules through a specific reaction pathway.

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

What are enzymes used for in medicine?

A

Treat diseases (lactose intolerance), generate drugs (penicillin), and diagnose diseases.

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

What is the Km value of an enzyme an indicator for?

A

Its affinity for the substrate.

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

How is reversible binding of enzymes possible?

A

Due to the 3-D structure of proteins generating sites for other molecules.

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

Enzymatic Binding Sites

A

Very specific for a particular ligand and binding is reversible.

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

How to tell if it is an enzyme?

A

All enzymes end in -ase.

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

What are the major classes of enzymes?

A
  1. Oxidorectuctases
  2. Transferases
  3. Hydrolases
  4. Lyases
  5. Isomerases
  6. Ligases
  7. Polymerases
  8. Proteases
  9. Kinases
  10. ATPases
  11. Synthases
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What do oxidoreductases do?

A

Reactions where one molecules is oxidized while the other is reduced. (oxidases, reductases, dehyrdogenases)

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

What do transferases do?

A

Transfer carbon, nitrogen or phosphate groups.

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

What do hydrolases do?

A

Catalyze a hydrolytic cleavage reaction. (nucleases and proteases)

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

What do lyases do?

A

Catalyze the cleavage of C-C, C-S, and C-N bonds.

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

What do isomerases do?

A

Catalyze the arrangement of bonds within a single molecule.

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

What do ligases do?

A

Join together (ligate) two molecules in an energy dependent process.

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

What do polymerases do?

A

Catalyze polymerization reactions; synthesis of DNA and RNA.

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

What do proteases do?

A

Breakdown proteins by hydrolyzing bonds between amino acids.

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

What do kinases do?

A

Catalyze the addition of phosphate groups to molecules.

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

What to ATPases do?

A

Hydrolyze ATP.

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

What do synthases do?

Study These Flashcards
A

Synthesize molecules in anabolic reactions by condensing two smaller molecules together.

20
Q

Enzyme Active Site

Study These Flashcards
A

Special pocket for substrate binding. Binding causes a conformational change in the enzyme that allows catalysis to proceed.

21
Q

Properties of Enzymes

Study These Flashcards
A
  1. Efficiency
  2. Specificity
  3. Sometimes they require cofactors to work.
  4. Can be regulated; increased and decreased.
  5. Located in specific organelles.
22
Q

Km Value

Study These Flashcards
A

Discovered by Michaelis; the Michaelis Constant; AFFINITY of the enzyme of its substrate.

23
Q

What type of curve do allosteric enzymes show?

Study These Flashcards
A

Sigmoidal Curve

24
Q

What type of curve do enzymes that follow the Michaelis-Menten kinetics show?

Study These Flashcards
A

Hyperbolic Curve

25
What do allosteric enzyme do?
They change the conformation of the binding site.
26
How does substrate concentration affect the velocity of the reaction?
The rate of an enzyme reaction increases with substrate concentration until a maximal velocity (Vmax) is reached.
27
How does temperature affect the velocity of a reaction?
Reaction velocity increases with temperature until a peak is reached. Too high temperature will lead to denaturation. OPTIMAL TEMP: 35-40C
28
How does pH affect the velocity of a reaction?
Extreme pH (concentration of H+) will denature enzymes. Optimum pH of enzymes will vary.
29
What is an enzyme inhibitor?
Any substance that can diminish the velocity of an enzyme-catalyzed reaction.
30
What is a competitive inhibitor?
Bind to the same site that the substrate would occupy, reducing affinity. Increases Km, Vmax is unchanged.
31
What is a noncompetitive inhibitor?
Binds at a different site from the substrate. Preventing the reaction from occurring. Decreases the Vmax. Do NOT interfere with the binding of the substrate to the enzyme.
32
What are cofactors used for?
Small molecules used as a helper of the catalytic activity of many enzymes.
33
What is a zymogen?
Inactive enzyme precursor. Example: trypsinogen, proinsulin and pepsinogen. Ends in -inogen or begins with pro-.
34
What is the cofactor for the enzyme lactate dehydrogenase?
nicotinamide adenine dinucleotide.
35
What is the cofactor for the enzyme Acetyl CoA carboxylase?
Coenzyme A (CoA).
36
What are coenzymes?
Cofactors that are small organic molecules. Often derived from vitamins.
37
Which coenzymes bind tightly?
Prosthetic groups. Example: heme group.
38
What is the cofactor for hexokinase?
Mg2+
39
What are mechanisms for regulating enzyme activity?
Gene expression (slow control but lasts longer) and enzyme activity.
40
What does covalent modification do to enzyme activity?
Turn enzyme on or off by adding/removing phosphate groups from specific amino acids.
41
What does allosteric regulation do to an enzyme?
Controls enzyme kinetics. Conformational change of an enzyme.
42
What regulation mechanisms affect enzyme activity?
Covalent modification and allosteric regulation.
43
How are allosteric enzymes regulated?
By effectors that bind at a site other than the active site altering the affinity of the enzyme for its substrate.
44
What is a homotropic effector?
The substrate itself serves as the effector. Ex: hemoglobin.
45
What is a heterotrophic effector?
Feedback inhibition.
46
What does the induction or repression of enzyme synthesis do?
Regulates the amount of enzyme, altering the rate of enzyme degradation or the rate of synthesis.

VP Cell Physiology (5 decks)

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