Question 1

Which of the following statements concerning general-acid catalysis is correct?

Accepted Answer

A) The proton is transferred to the reactant during the slow step of the reaction. 
B) The transition state of the slow step of the reaction has a partially transferred proton instead of a fully transferred proton. 
C) Typically,a general-acid catalyst is stronger than a specific-acid catalyst. 
D) both A and B 
E) all of the above 
A) The proton is transferred to the reactant during the slow step of the reaction. 
B) The transition state of the slow step of the reaction has a partially transferred proton instead of a fully transferred proton. 
C) Typically,a general-acid catalyst is stronger than a specific-acid catalyst. 
D) both A and B 
E) all of the above D

Question 2

Describe the acid-catalyzed second slow step in the hydrolysis of an ester.

Accepted Answer

A) The electron pair on oxygen forms double bond and alcohol is the leaving group. 
B) The base abstracts extra hydrogen from protonated alcohol. 
C) The oxygen of the carbonyl group abstracts a hydrogen from HB. 
D) Water attacks the carbonyl carbon and electron pair goes to oxygen. 
E) The oxygen on the alkoxy group abstracts a hydrogen from HB. 
A) The electron pair on oxygen forms double bond and alcohol is the leaving group. 
B) The base abstracts extra hydrogen from protonated alcohol. 
C) The oxygen of the carbonyl group abstracts a hydrogen from HB. 
D) Water attacks the carbonyl carbon and electron pair goes to oxygen. 
E) The oxygen on the alkoxy group abstracts a hydrogen from HB. A

Question 3

The end product of glycolysis is

Accepted Answer

A) D-glucose. 
B) aldolase. 
C) fructose-1,6-bisphosphate. 
D) glyceraldehyle-3-phosphate. 
E) pyruvate. 
A) D-glucose. 
B) aldolase. 
C) fructose-1,6-bisphosphate. 
D) glyceraldehyle-3-phosphate. 
E) pyruvate. E

Question 4

Which of the following statements is true about catalysts?

Accepted Answer

A) They can be used only once. 
B) They participate in the chemical reaction,but are not changed or consumed. 
C) They change the stability of reactants and products. 
D) They change the amount of product formed in a chemical reaction. 
E) all of the above 
A) They can be used only once. 
B) They participate in the chemical reaction,but are not changed or consumed. 
C) They change the stability of reactants and products. 
D) They change the amount of product formed in a chemical reaction. 
E) all of the above

Question 5

Which of the following statements about how acid catalyzes the hydrolysis of esters is correct?

Accepted Answer

A) The acid catalyst increases the rate of formation of the tetrahedral intermediate by protonating the carbonyl and thereby increasing the reactivity of the carbonyl group. 
B) The acid catalyst increases the rate of the reaction by changing the basicity of the group eliminated when the tetrahedral intermediate collapses. 
C) The acid catalyst protonates the water,the nucleophile in the reaction,and thereby makes it a stronger nucloephile. 
D) both A and B 
E) all of the above 
A) The acid catalyst increases the rate of formation of the tetrahedral intermediate by protonating the carbonyl and thereby increasing the reactivity of the carbonyl group. 
B) The acid catalyst increases the rate of the reaction by changing the basicity of the group eliminated when the tetrahedral intermediate collapses. 
C) The acid catalyst protonates the water,the nucleophile in the reaction,and thereby makes it a stronger nucloephile. 
D) both A and B 
E) all of the above

Question 6

Describe the second step of a specific-base-catalyzed dehydration of a hydrate.

Accepted Answer

A) Base abstracts a proton,electron pair from O-H bond goes to oxygen. 
B) Negative charge from oxygen forms double bond,hydroxide departs as leaving group. 
C) Base abstracts a proton,electron pair from O-H bond forms a double bond,hydroxide departs as leaving group. 
D) Hydroxide departs as leaving group,then negative charge from oxygen forms a double bond. 
E) Electron pair from O-H bond forms a double bond,base abstracts a proton. 
A) Base abstracts a proton,electron pair from O-H bond goes to oxygen. 
B) Negative charge from oxygen forms double bond,hydroxide departs as leaving group. 
C) Base abstracts a proton,electron pair from O-H bond forms a double bond,hydroxide departs as leaving group. 
D) Hydroxide departs as leaving group,then negative charge from oxygen forms a double bond. 
E) Electron pair from O-H bond forms a double bond,base abstracts a proton.

Question 7

In what kind of acid catalysis is the proton transferred completely to the reactant before a subsequent slow step?

Accepted Answer

specific-a

Question 8

Give the product(s)for the following reaction.You may choose more than one answer.

Accepted Answer

A)    
B)    
C)    
D)    
E)    
A)    
B)    
C)    
D)    
E)

Question 9

List four common types of catalysts used in organic reactions and give one example of each.

Accepted Answer

The answer of List four common types of catalysts used...

Question 10

What technique is used to gain information about protein structure and function by replacing single amino acids along a peptide chain?

Accepted Answer

site-speci

Question 11

Which of the following are affected when an intramolecular catalyst is used?

Accepted Answer

A) number of collisions between the two per unit time 
B) fraction of collisions with sufficient energy 
C) fraction of collisions with proper orientation 
D) rate of the reaction 
E) all of the above 
A) number of collisions between the two per unit time 
B) fraction of collisions with sufficient energy 
C) fraction of collisions with proper orientation 
D) rate of the reaction 
E) all of the above

Question 12

Describe the acid-catalyzed first slow step in the hydrolysis of an ester.

Accepted Answer

A) The electron pair on oxygen forms double bond and alcohol is the leaving group. 
B) The base abstracts extra hydrogen from protonated alcohol. 
C) The oxygen of the carbonyl group abstracts a hydrogen from HB. 
D) Water attacks the carbonyl carbon and electron pair goes to oxygen. 
E) The oxygen on the alkoxy group abstracts a hydrogen from HB. 
A) The electron pair on oxygen forms double bond and alcohol is the leaving group. 
B) The base abstracts extra hydrogen from protonated alcohol. 
C) The oxygen of the carbonyl group abstracts a hydrogen from HB. 
D) Water attacks the carbonyl carbon and electron pair goes to oxygen. 
E) The oxygen on the alkoxy group abstracts a hydrogen from HB.

Question 13

How does a base catalyst increase the rate of reaction?

Accepted Answer

by removin

Question 14

The reaction below occurs by a general-acid catalyzed mechanism.Use curved arrows to illustrate the ring-forming step of the mechanism.

Accepted Answer

The answer of The reaction below occurs by a general-acid...

Question 15

Explain what is meant by anchimeric assistance and give an example.

Accepted Answer

In Greek,anchimeric means "adj

Question 16

Predict the product of the following reaction involving general acid catalysis.
(Hint: Five membered ring is formed through intramolecular cyclization.)

Accepted Answer

The answer of Predict the product of the following reaction...

Question 17

Why is histidine a versatile catalytic group?

Accepted Answer

Because the imidazole ring in

Question 18

How does an acid catalyst speed up the reaction below?

Accepted Answer

Protonating the aziridine's N atom incre

Question 19

Which of the following is an intermediate in the mechanism of hydrolysis of the ester shown below?

Accepted Answer

A)    
B)    
C)    
D)    
E) all of the above 
A)    
B)    
C)    
D)    
E) all of the above

Question 20

Which of the following is not true about the enzyme aldolase?

Accepted Answer

A) It catalyzes the cleavage of D-glucose into two molecules each containing 3-carbons. 
B) It catalyzes the cleavage of D-galactose into two molecules each containing 3-carbons. 
C) It catalyzes the cleavage of a six carbon compound into two three carbon compounds. 
D) It catalyzes the cleavage of D-fructose 1,6-diphosphate into glyceraldehyde-3-phosphate and dihydroxyacetone phosphate. 
E) The enzyme is called aldolase because the reverse reaction is an aldol condensation. 
A) It catalyzes the cleavage of D-glucose into two molecules each containing 3-carbons. 
B) It catalyzes the cleavage of D-galactose into two molecules each containing 3-carbons. 
C) It catalyzes the cleavage of a six carbon compound into two three carbon compounds. 
D) It catalyzes the cleavage of D-fructose 1,6-diphosphate into glyceraldehyde-3-phosphate and dihydroxyacetone phosphate. 
E) The enzyme is called aldolase because the reverse reaction is an aldol condensation.

Exam 22: Catalysis in Organic Reactions and in Enzymatic Reactions

Which of the following statements concerning general-acid catalysis is correct?

Describe the acid-catalyzed second slow step in the hydrolysis of an ester.

The end product of glycolysis is

Which of the following statements is true about catalysts?

Which of the following statements about how acid catalyzes the hydrolysis of esters is correct?

Describe the second step of a specific-base-catalyzed dehydration of a hydrate.

In what kind of acid catalysis is the proton transferred completely to the reactant before a subsequent slow step?

Give the product(s)for the following reaction.You may choose more than one answer.

List four common types of catalysts used in organic reactions and give one example of each.

What technique is used to gain information about protein structure and function by replacing single amino acids along a peptide chain?

Which of the following are affected when an intramolecular catalyst is used?

Describe the acid-catalyzed first slow step in the hydrolysis of an ester.

How does a base catalyst increase the rate of reaction?

The reaction below occurs by a general-acid catalyzed mechanism.Use curved arrows to illustrate the ring-forming step of the mechanism.

Explain what is meant by anchimeric assistance and give an example.

Predict the product of the following reaction involving general acid catalysis. (Hint: Five membered ring is formed through intramolecular cyclization.)

Why is histidine a versatile catalytic group?

How does an acid catalyst speed up the reaction below?

Which of the following is an intermediate in the mechanism of hydrolysis of the ester shown below?

Which of the following is not true about the enzyme aldolase?

Remembering General Chemistry: Electronic Structure and Bonding

Acids and Bases: Central to Understanding Organic Chemistry

An Introduction to Organic Compounds: Nomenclature, physical Properties, and Structure

Isomers: the Arrangement of Atoms in Space

Alkenes: Structure,nomenclature,and an Introduction to Reactivity - Thermodynamics and Kinetics

The Reactions of Alkenes - the Stereochemistry of Addition Reactions

The Reactions of Alkynes - Introduction to Multistep Synthesis

Delocalized Electrons: Their Effect on Stability, pka, and the Products of a Reaction - Aromaticity and Electronic Effects: an Introduction to the Reactions of Benzene

Substitution and Elimination Reactions of Alkyl Halides

Reactions of Alcohols, ethers, epoxides, amines and Sulfur-Containing Compounds

Organometallic Compounds

Radicals

Mass Spectrometry,infrared Spectroscopy,and Uvvis Spectroscopy

Nmr Spectroscopy

Reactions of Carboxylic Acids and Carboxylic Acid Derivatives

Reactions of Aldehydes and Ketones

Reactions at the Α-Carbon

Reactions of Benzene and Substituted Benzenes

More About Amines - Reactions of Heterocylic Compounds

The Organic Chemistry of Carbohydrates

Amino Acids,peptides,and Proteins

The Organic Chemistry of the Coenzymes, compounds Derived From Vitamins

The Organic Chemistry of the Metabolic Pathways

The Organic Chemistry of Lipids

The Chemistry of the Nucleic Acids

Synthetic Polymers

Pericyclic Reactions

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