Transcript Amino acid quiz (PowerPoint)

Amino acids &
peptides
Practice Quiz
(you will need your amino acid sheet for this quiz)
Question 1
a)
b)
c)
d)
Approximately what mass
percent of a body’s dry
weight consists of proteins?
5%
25%
50%
72%
Answer: C) sorry, did I forget to
mention that in class?
Question 2
a)
b)
c)
d)
Which functional group, in addition to an amine, do
all amino acids contain?
an alcohol
an amide
a carboxylic acid
an oxyacid
Answer: C)
Question 3
A peptide bond links
a) an alcohol and a ketone
b) an amide and an aldehyde
c) an amine and a carboxylic acid
d) an amide and a carboxylic acid
peptide bond
amine
Answer: C)
H2N
O
CH
CH3
C
O
H
N
CH
CH2
SH
C
carboxylic acid
OH
Question 4
a)
b)
c)
d)
What does the term ‘α-amino acid mean?
The amino acid attaches to the carbon in the
carboxyl group
The amino group attaches to the carbon next to
the carboxylic acid group
The amino acid contains only one carbon atom
The amino acid contains
only one carboxylic
-carbon atom
O
acid group
H2N
Answer: b)
CH
C
CH
OH
CH3
OH
Question 5
When referring to amino acids, what does the
term essential mean? These are acids which
a) are necessary for digestion
b) are necessary for respiration
c) are synthesized in our bodies
d) we must obtain from our diet
Answer: d)
Question 6
Which of the following amino acids is not
basic?
a) arginine
b) glycine
c) histidine
d) lysine
Answer: b)
Question 7
a)
b)
c)
d)
Which of the following
amino acids is acidic?
alanine
aspartic
glycine
valine
Answer: b)
O
H2N
CH
C
CH2
C
OH
O
OH
Question 8
a)
b)
c)
d)
Which one of the following amino acids
contains a double ring structure?
phenylalanine
proline
O
tryptophan
H2N
CH
C
OH
tyrosine
CH
2
Answer: C)
HN
Question 9
a)
b)
c)
d)
Which one of the following amino acids
contains a benzyl group?
glycine
O
isoleucine
H 2N
CH
C
OH
methionine
CH2
phenylalanine
Answer: d)
Question 10
What does the term hydrophobic mean?
a) water reactive
b) water repelling
c) water soluble
d) water proof
Answer: b)
Question 11
a)
b)
c)
d)
Which of the following amino acids is
hydrophobic?
leucine
O
serine
threonine
H2N
CH
C
OH
tyrosine
CH2
Answer: a)
CH
CH3
non-polar side chain
CH3
Question 12
a)
b)
c)
d)
All but one of the common amino acids contain a –NH2
amino group. Which one contains an –NH- amino acid
as part of a ring structure?
O
phenylalanine
proline
C
OH
tryptophan
tyrosine
Answer: b)
HN
Question 13
 In how many different ways can the amino
a)
b)
c)
d)
acids: ALA, CYS, MET, GLU, SER and TYR
connect together to form a polypeptide?
Over 5000
720
120
21
Answer:
b) 6! = 720
Question 14

The diagram is an
example of:
a) An L-amino acid
b) A D-amino acid
c) An achiral-amino acid
d) An amino acid residue
Answer: a)
O
OH
C
H2N
C
R
H
Question 15
 What kind of bonding stabilises helical and
β-pleated-sheet secondary protein
structure?
a) Vander Waals forces
b) Hydrogen bonding
c) Interactions with neighbouring protein chains
d) Helical and sheet structures are tertiary, not
secondary structures
Answer: b)
Who’s your favourite Chemistry
teacher?
a) A Kevin
b) A nother
c) A non
d) None of the above
Answer: a) A Kevin
(of course)