Question 1

What supports the theory that a catalytic triad strategy is a result of convergent evolution?

Accepted Answer

A number of different enzymes,including ...

Question 2

The sequence 6 bp restriction cleavage site for EcoRV is GATXXX.What is the complete sequence of the double-stranded restriction site?

Accepted Answer

The answer of The sequence 6 bp restriction cleavage site...

Question 3

Why are substrate analogs often used to monitor enzyme activity?

Accepted Answer

Enzyme assays must be designed so that f...

Question 4

What type of symmetry is created by inverted repeats in double-stranded DNA?

Accepted Answer

A)   two-fold rotational
B)   three-fold rotational
C)   mirror plane
D)   line
E)   inversion centerF) A) and B)
G) B) and E)

Question 5

Metal ion catalysis is facilitated by any of several mechanisms,including

Accepted Answer

A)   stabilizing negative charges on an intermediate.
B)   promoting formation of nucleophiles.
C)   metals binding directly to substrates.
D)   stabilizing negative charges on an intermediate and metals binding directly to substrates.
E)   All of the answers are correct.F) B) and C)
G) A) and E)

Question 6

What is the challenge for a protease to facilitate hydrolysis of a peptide bond?

Accepted Answer

The peptide bond contains a carbonyl that is not very reactive; therefore,the catalytic mechanism must employ a feature that promotes nucleophilic attack of this carbonyl group by a strong nucleophile so the peptide bond can be cleaved.

Question 7

Restriction endonucleases cut DNA at specific sites.How many different patterns can be formed by a four-base sequence combination of any four bases?

Accepted Answer

A)   64
B)   256
C)   16
D)   1024
E)   4096F) A) and E)
G) C) and D)

Question 8

Kinetic studies on myosins,in the presence and absence of divalent cations,show that ________________ is the true substrate for this enzyme.

Accepted Answer

The answer of Kinetic studies on myosins,in the presence and...

Question 9

In trypsin,the specificity pocket contains a/an ______________ residue that binds to the positive charge of the K or R residue of the substrate.

Accepted Answer

aspartyl,a...

Question 10

The catalytic mechanism ofcarbonic anhydrase,in which the substrates are simply oriented to stabilize the transition state,is called ___________________.

Accepted Answer

catalysis ...

Question 11

Designing drugs to inhibit enzymes is a large part of pharmaceutical research.What are some of the enzymatic features that would be important?

Accepted Answer

The enzyme could be inhibited by interac...

Question 12

Type II restriction enzymes cut

Accepted Answer

A)   double-stranded DNA, forming a 5' phosphoryl group and a 3' hydroxyl group on each strand.
B)   single-stranded DNA, forming a 5' phosphoryl group and a 3' hydroxyl group on the strand.
C)   double-stranded DNA, forming a 5' phosphoryl group and a 3' hydroxyl group on one strand.
D)   double-stranded DNA, forming a 3' phosphoryl group and a 5' hydroxyl group on each strand.
E)   single-stranded DNA, forming two hydroxyl groups and loss of a phosphate group.F) D) and E)
G) C) and D)

Question 13

How is the bicarbonate formed when carbonic anhydrase is present?

Accepted Answer

The zinc promotes fo...

Question 14

How is specificity determined by chymotrypsin?

Accepted Answer

A)   interaction of the active site amino acids with the substrate
B)   binding of the N-terminus amino acid at the active site
C)   covalent binding of a His residue to the substrate
D)   large conformational change of a P-loop upon binding of substrate
E)   binding of the proper amino acid into a deep pocket on the enzymeF) A) and C)
G) C) and D)

Question 15

The reaction center of most carbonic anhydrases is a zinc ion bound to water and _______________ residues of the enzyme.

Accepted Answer

histidine

Question 16

Which of the following is NOT a way in which enzymes stabilize a transition state?

Accepted Answer

A)   causing the temperature of the environment to increase
B)   covalent catalysis
C)   using binding energy
D)   general acid-base catalysis
E)   catalysis by approximationF) A) and B)
G) A) and C)

Question 17

Where does cleavage of the scissile bond by chymotrypsin occur?

Accepted Answer

A)   between a His and Ser amino acid
B)   on the N-terminal side of a Phe or Trp residue
C)   on the C-terminal side of a Phe or Trp residue
D)   at the N-terminal amino acid
E)   on the C-terminal side of an Arg or Lys amino acidF) A) and B)
G) C) and D)

Question 18

What process converts chymotrypsinogen to chymotrypsin?

Accepted Answer

A)   metal ion binding
B)   peptide bond cleavage
C)   coenzyme association
D)   cysteine methylation
E)   proline hydroxylationF) A) and E)
G) A) and B)

Question 19

The mechanism of chymotrypsin involves the formation of an unstable __________________ -shaped intermediate that is stabilized by the oxyanion hole.

Accepted Answer

tetrahedral

Question 20

Myosins hydrolyze _____________ in a controlled manner and use the free energy of hydrolysis to promote conformational changes within myosin itself.

Accepted Answer

The answer of Myosins hydrolyze _____________ in a controlled manner...

Exam 9: Catalytic Strategies

What supports the theory that a catalytic triad strategy is a result of convergent evolution?

Correct AnswerverifiedA number of different enzymes,including ...View AnswerShow Answer

The sequence 6 bp restriction cleavage site for EcoRV is GATXXX.What is the complete sequence of the double-stranded restriction site?

Correct AnswerverifiedShow Answer

Why are substrate analogs often used to monitor enzyme activity?

Correct AnswerverifiedEnzyme assays must be designed so that f...View AnswerShow Answer

What type of symmetry is created by inverted repeats in double-stranded DNA?

Correct AnswerverifiedShow Answer

Metal ion catalysis is facilitated by any of several mechanisms,including

Correct AnswerverifiedShow Answer

What is the challenge for a protease to facilitate hydrolysis of a peptide bond?

Correct AnswerverifiedThe peptide bond contains a carbonyl that is not very reactive; therefore,the catalytic mechanism must employ a feature that promotes nucleophilic attack of this carbonyl group by a strong nucleophile so the peptide bond can be cleaved.

Restriction endonucleases cut DNA at specific sites.How many different patterns can be formed by a four-base sequence combination of any four bases?

Correct AnswerverifiedShow Answer

Kinetic studies on myosins,in the presence and absence of divalent cations,show that ________________ is the true substrate for this enzyme.

Correct AnswerverifiedShow Answer

In trypsin,the specificity pocket contains a/an ______________ residue that binds to the positive charge of the K or R residue of the substrate.

Correct Answerverifiedaspartyl,a...View AnswerShow Answer

The catalytic mechanism ofcarbonic anhydrase,in which the substrates are simply oriented to stabilize the transition state,is called ___________________.

Correct Answerverifiedcatalysis ...View AnswerShow Answer

Designing drugs to inhibit enzymes is a large part of pharmaceutical research.What are some of the enzymatic features that would be important?

Correct AnswerverifiedThe enzyme could be inhibited by interac...View AnswerShow Answer

Type II restriction enzymes cut

Correct AnswerverifiedShow Answer

How is the bicarbonate formed when carbonic anhydrase is present?

Correct AnswerverifiedThe zinc promotes fo...View AnswerShow Answer

How is specificity determined by chymotrypsin?

Correct AnswerverifiedShow Answer

The reaction center of most carbonic anhydrases is a zinc ion bound to water and _______________ residues of the enzyme.

Correct Answerverifiedhistidine

Which of the following is NOT a way in which enzymes stabilize a transition state?

Correct AnswerverifiedShow Answer

Where does cleavage of the scissile bond by chymotrypsin occur?

Correct AnswerverifiedShow Answer

What process converts chymotrypsinogen to chymotrypsin?

Correct AnswerverifiedShow Answer

The mechanism of chymotrypsin involves the formation of an unstable __________________ -shaped intermediate that is stabilized by the oxyanion hole.

Correct Answerverifiedtetrahedral

Myosins hydrolyze _____________ in a controlled manner and use the free energy of hydrolysis to promote conformational changes within myosin itself.

Correct AnswerverifiedShow Answer

Correct Answer
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A number of different enzymes,including ...
View Answer

Correct Answer
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Correct Answer
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Enzyme assays must be designed so that f...
View Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
The peptide bond contains a carbonyl that is not very reactive; therefore,the catalytic mechanism must employ a feature that promotes nucleophilic attack of this carbonyl group by a strong nucleophile so the peptide bond can be cleaved.

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
aspartyl,a...
View Answer

Correct Answer
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catalysis ...
View Answer

Correct Answer
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The enzyme could be inhibited by interac...
View Answer

Correct Answer
verified

Correct Answer
verified
The zinc promotes fo...
View Answer

Correct Answer
verified

Correct Answer
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histidine

Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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tetrahedral

Correct Answer
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