Block Five

Question 1

What is the order of reactiveness of carboxylic acid derivatives?

Answer 1

Acyl chloride > Acid anhydrides > Esters > Amides > Carboxylic acids

Question 2

When are amines basic?

Answer 2

When they have no charge

Question 3

How does pKa relate to the basicity of an amine?

Answer 3

The higher the pKa for the conjugate acid, the higher the basicity of the amine

Question 4

Do electron withdrawing groups increase or decrease basicity?

Answer 4

Decrease

Question 5

Why do mixtures form when alkyl halides undergo substitution reactions with excess NH3?

Answer 5

The amines continue to react forming primary, tertiary and quaternary amines

Question 6

How are aromatic amines formed from a benzene ring with NO2 attached?

Answer 6

Fe/H+ and OH-

Ch3Br

Question 7

Which four functional groups can be reduced by LiAlH4 and H3O+ to form primary amines?

Answer 7

Oximes, imines, nitriles, and primary amides

Question 8

What do the reagenst NaOEt and EtOH cause?

Answer 8

Condensation if the reactant has an alpha proton

Question 9

When a tertiary amide reacts with LiAlH4 and H3O+ what forms?

Answer 9

A tertiary amine

Question 10

Why can tertiary amines not react with acyl chlorides to form amides like secondary and primary amines?

Answer 10

HCl cannot be formed as a byproduct so the reaction does not occur

Question 11

What are the two ways to form a primary amide with ammonia?

Answer 11

Acid chloride and acid anhydride

Question 12

How are tertiary amides formed?

Answer 12

Secondary amines with acid chloride

Question 13

Which reagents are required to convert an aryl amide into and aryl amine?

Answer 13

70% aq H2SO4

OH-

Question 14

What are the functional groups of amino acids?

Answer 14

Amine and carboxylic acid around a stereogenic centre

Question 15

What is the overall charge of an amino acid in acidic solution?

Answer 15

+1

Question 16

When is an amino acid in zwitterion form?

Answer 16

In neutral solution

Question 17

What is the function of protected derivatives?

Answer 17

Ensure that the NH2 of glycine and the COOH of alanine so that they cannot react and only the desired dipeptide will form

Question 18

Why is DCC necessary in the reaction of Gly and Ala?

Answer 18

It enhances the reactivity of the carboxylic acid forming an active ester

Question 19

What is the angle about an amide bond?

Answer 19

Planar at 180 degrees

Question 20

Are anti parallel or parallel Beta Sheets more stable?

Answer 20

Anti-parallel

Question 21

Is a chain of fewer than fifty amino acid bonds a peptide or a protein?

Answer 21

Peptide

Question 22

What is the process of enzymes lowering the activation energy for reactions?

Answer 22

Enzyme + Substrate = Enzyme + Product

Question 23

What occurs when a carbonyl compound with an alpha proton is reacted with either an acid or a strong base?

Answer 23

An enol or enolate is formed

Question 24

Which reagents are required to convert a ketone to an alcohol?

Answer 24

NaBH4 or LiAlH4

H3O+

Question 25

What reagent is needed to convert an alcohol to a ketone?

Answer 25

H2CrO4

Question 26

What causes the formation of a cyclic compound via a peptide bond?

Answer 26

Heat