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Chapter 3 Amino Acids, Peptides, and Proteins

Multiple Choice Questions

1.    Amino acids

Page: 76 Difficulty: 1 Ans: C

Tlie chirality of an amino aad results from the fect that lts a carbon

A)    has no net charge

B)    isa carboxyhcaad

C)    is bonded to four different Chemical groups

D)    is m the l absolute configuration m naturally ocaunng proteins

E)    is symmetnc

2.    Amino acids

Page: 76 Difficulty: 2 Ans: B

Of the 20 standard amino aads, only_is not optically active The reason is that lts side

cham    .

A)    alaninę, is a simple methyi group

B)    glyane, is a hydrogen atom

C)    glyane, is unbranched

D)    łysinę, contams only nitro gen

E)    proline, forms a covalent bond with the amino group

3.    Amino acids

Page: 79 Difficulty: 1 Ans: C

Two amino aads of the standard 20 contam sulfur atoms Tliey are

A)	cysteinę and senne
B)	cysteme and threomne
C)	methionine and cysteme
D)	methionme and senne
E)	threonine and senne
Amino acids
Page: 79	Difficulty: 1 Ans: A

Ali of the amino aads that are found m proteins, except for proline, contam a(n):

A)    amino group

B)    caibonyl group

C)    carboxyl group

D)    ester group

E)    thiol group