Amino Acids, Peptides, and Proteins Flashcards

1
Q

What are the amino acids encoded in the genetic code called?

A

proteinogenic amino acids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Which amino acid is achiral?

A

glycine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Amino acids in eukaryotes are D or L?

A

L

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Amino acids are all S/R except for ______?

A

S except for cysteine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Which two amino acids contain sulfur?

A

methionine and cysteine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q
Glycine
Polar/Nonpolar =
Charge =
Aromatic/Nonaromatic =
Hydrophilic/Hydrophobic =
A

nonpolar
neutral
nonaromatic
neither

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q
Alanine
Polar/Nonpolar =
Charge =
Aromatic/Nonaromatic =
Hydrophilic/Hydrophobic =
A

nonpolar
neutral
nonaromatic
hydrophobic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q
Valine
Polar/Nonpolar =
Charge =
Aromatic/Nonaromatic =
Hydrophilic/Hydrophobic =
A

nonpolar
neutral
nonaromatic
hydrophobic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q
Leucine
Polar/Nonpolar =
Charge =
Aromatic/Nonaromatic =
Hydrophilic/Hydrophobic =
A

nonpolar
neutral
nonaromatic
hydrophobic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q
Isoleucine
Polar/Nonpolar =
Charge =
Aromatic/Nonaromatic =
Hydrophilic/Hydrophobic =
A

nonpolar
neutral
nonaromatic
hydrophobic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q
Methionine
Polar/Nonpolar =
Charge =
Aromatic/Nonaromatic =
Hydrophilic/Hydrophobic =
A

nonpolar
neutral
nonaromatic
neither

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q
Proline
Polar/Nonpolar =
Charge =
Aromatic/Nonaromatic =
Hydrophilic/Hydrophobic =
A

nonpolar
neutral
nonaromatic
neither

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q
Tryptophan 
Polar/Nonpolar =
Charge =
Aromatic/Nonaromatic =
Hydrophilic/Hydrophobic =
A

nonpolar
neutral
aromatic
neither

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q
Phenylalanine
Polar/Nonpolar =
Charge =
Aromatic/Nonaromatic =
Hydrophilic/Hydrophobic =
A

nonpolar
neutral
aromatic
hydrophobic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q
Tyrosine
Polar/Nonpolar =
Charge =
Aromatic/Nonaromatic =
Hydrophilic/Hydrophobic =
A

polar
neutral
aromatic
neither

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q
Serine
Polar/Nonpolar =
Charge =
Aromatic/Nonaromatic =
Hydrophilic/Hydrophobic =
A

polar
neutral
nonaromatic
neither

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q
Threonine
Polar/Nonpolar =
Charge =
Aromatic/Nonaromatic =
Hydrophilic/Hydrophobic =
A

polar
neutral
nonaromatic
neither

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q
Asparagine
Polar/Nonpolar =
Charge =
Aromatic/Nonaromatic =
Hydrophilic/Hydrophobic =
A

polar
neutral
nonaromatic
neither

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q
Glutamine
Polar/Nonpolar =
Charge =
Aromatic/Nonaromatic =
Hydrophilic/Hydrophobic =
A

polar
neutral
nonaromatic
neither

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q
Cysteine
Polar/Nonpolar =
Charge =
Aromatic/Nonaromatic =
Hydrophilic/Hydrophobic =
A

polar
neutral
nonaromatic
neither

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q
Aspartic Acid
Polar/Nonpolar =
Charge =
Aromatic/Nonaromatic =
Hydrophilic/Hydrophobic =
A

polar
negative
nonaromatic
hydrophilic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q
Glutamic Acid
Polar/Nonpolar =
Charge =
Aromatic/Nonaromatic =
Hydrophilic/Hydrophobic =
A

polar
negative
nonaromatic
hydrophilic

23
Q
Lysine
Polar/Nonpolar =
Charge =
Aromatic/Nonaromatic =
Hydrophilic/Hydrophobic =
A

polar
positive
nonaromatic
hydrophilic

24
Q
Arginine
Polar/Nonpolar =
Charge =
Aromatic/Nonaromatic =
Hydrophilic/Hydrophobic =
A

polar
positive
nonaromatic
hydrophilic

25
``` Histidine Polar/Nonpolar = Charge = Aromatic/Nonaromatic = Hydrophilic/Hydrophobic = ```
polar positive aromatic hydrophilic
26
How many pKa values do amino acids have and what are they?
at least two the first one is the deprotonation of the carboxyl group around 2 the second one is the deprotonation of the amino group around 9/10
27
At very acidic pH values, amino acids tend to be _____ charged.
positively
28
What is the isoelectric point?
the pH at which the molecule is electrically neutral
29
pI of a neutral amino acid
pKa amino group + pKa carboxylic acid / 2
30
pI of a acidic amino acid
pKa R group + pKa carboxylic acid / 2
31
pI of a basic amino acid
pKa amino group + pKa R group / 2
32
What is a peptide bond?
a specialized form of an amide bond, which form between the -COO- group of one amino acid and the NH3+ group of another amino acid
33
Peptides read from the _-terminus to the _-terminus.
N to C
34
How do hydrolytic enzymes hydrolyze peptides?
Break apart amide bond by adding a hydrogen atom to the amide nitrogen and an OH group to the carbonyl carbon
35
Where does trypsin cleave?
carboxyl end of arginine and lysine
36
Where does chymotrypsin cleave?
at the carboxyl end of phenylalanine, tryptophan and tyrosine
37
What is the primary structure of a protein?
the linear arrangement of amino acids coded in an organism's DNA
38
What is the secondary structure of a protein?
the local structure of neighboring amino acids
39
What are two secondary structures?
alpha helix and beta sheets
40
Which bonds hold the secondary structure together?
hydrogen bonds
41
What is proline useful for?
found at the turns between beta sheets and start of alpha helix due to its kinking properties
42
What are fibrous proteins?
structures that resemble sheets or long strands
43
What are globular proteins?
structures that are spherical
44
What is tertiary structure?
three-dimensional shape
45
What determines the tertiary structure?
hydrophilic and hydrophobic interactions between the R groups
46
What are quaternary structures?
aggregate of smaller globular peptides (multiple polypeptides chains) that function as a protein
47
Four reasons for having quaternary structure?
(1) more stable by reducing the surface area of the protein complex (2) reduce amount of DNA needed to encode the protein complex (3) bring catalytic sites close together, allowing intermediates from one reaction to be directly shuttled to a second reaction (4) Cooperativity/allosteric effects
48
What are conjugated proteins?
proteins with have covalently attached molecules known as prosthetic groups
49
What are lipoproteins?
proteins with lipid prosthetic groups
50
What are glycoproteins?
proteins with carbohydrate prosthetic groups
51
What are nucleoproteins?
proteins with nucleic acid prosthetic groups
52
What are prosthetic groups needed for?
- can direct protein to be delivered to a certain location | - affect activity of protein
53
Which amino acids have chiral carbons in their side chains?
serine and threonine