Proteins Part 1 Flashcards
1
Q
General formula of proteins
A
CHON
Carbon Hydrogen Oxygen and Nitrogen some sulfur
2
Q
Greek word of protein and its meaning
A
Proteios
Of primary importance
3
Q
Swedish chemist that described and named in 1839
A
Jons Jakob Berzelius
4
Q
In 1926 he showed the enzyme urease was a protein
A
James B. Sumner
5
Q
Basic unit of proteins
A
Amino acids
6
Q
It is a naturally-occuring, unbranched polymer in which the monomer units are amino acids
A
Protein
7
Q
Most abundant molecules in the cells of humans
A
Protein
8
Q
Elemental composition of proteins
A
CHON
9
Q
Average nitrogen content of proteins is
A
15.4%
10
Q
Present in some specialiazed proteins
A
Iron Fe
Phosphorus P
11
Q
An organic compound that contains both an amino NH2 and Carboxyl COOH groups attached to same carbon atom
A
Amino acid
12
Q
the R side chain determines the ___ of amino acids
A
Classification
13
Q
R side chain may vary
A
In size shape charge acidity functional groups present hydrogen bonding ability and chemical reactivity
14
Q
Based on common r groups there are
A
20 standard amino acids
15
Q
r groups are non polar
A
Non polar amino acids
16
Q
Number of standard amino acids are non polar
A
8 of the 20
17
Q
R groups are polar
A
Polar amino acids
18
Q
Three types of polar amino acids
A
Polar neutrak polar acidic and polar basic
19
Q
R side with 2 COOh
A
Polar acidic
20
Q
Contains polar but neutral side chains
A
Polar neutral
21
Q
Contains amino group as part of the side chains
A
Polar basic
22
Q
Smallest amino acid
Achiral only= no isomerism
A
Glycine
23
Q
A
ALA
A
Alanine
24
Q
Arg
R
A
Arginine
25
ASP
D
Aspartic Acid
26
Asn
N
Asparagine
27
Cys
C
Cysteine
28
Glu
E
Glutamic Acid
29
Gln
Q
Glutamine
30
Gly
G
Glycine
31
His
H
Histidine
32
Ile
I
Isoleucine
33
Leu
L
Leucine
34
Lys
K
Lysine
35
Met
M
Methionine
36
Phe
F
Phenylalanine
37
Pro
P
Proline
38
Ser
S
Serine
39
Thr
T
Threonine
40
Trp
W
Tryptophan
41
Tyr
Y
Tyrosine
42
Val
V
Valine
43
Not synthesized by humans, can only be obtained in Food
Essential Amino Acids
44
It is required for growth in children but is not an essential amino acid for adults
Arginine
45
Essential amino acids for
Adult
Children
9-Adult
10- children
46
Metabolic fates
Exclusively ketogenic
K- Lysine
L-leucine
47
Metabolic fates
Both ketogenic and glucogenic
I- isoleucine
T-threonine
W-tryptophan
Y-tyrosine
F- phenylalanine
48
A protein that contains all of the essential amino acids in the same relative amounts in which the body needs them and examples
Complete dietary protein
Example Casein from milk and proteins in meat fish and eggs
From animal sources
49
Protein that does not contain adequate amounts relative to the bodys needs of one or more of the essential amino acids
Incomplete dietary protein
Protein from plant sources
Gelatin (Arg)
50
Common Limiting amino acid (LAA)
Lysine- wheat rice oats
Methionine-beans and peas
Tryptophan-corn and beans
51
Only complete dietary protein from plant
Soyq
52
Two or more incomplete dietary proteins that when combined provide an adequate amount of all essential amino acids relative to the body
Example
Complementary dietary proteins
Rice and beans
53
Amino acids found in nature as well as in proteins are what isomers?
L-isomers
54
Ile and Thr have ___ chiral center
2
55
Physical properties of proteins
Pure form- white crystalline
Decompose before they melt
Not very soluble in water
56
An ion with positive and negative charges on the same molecule
Zwitterion
57
The only standard amino acid with a sulfhydryl group -SH
Cysteine
58
Mild oxidizing agents dimerizes to form a
Cystine molecule
59
Two cysteine residues linked via a covalent disulfide bond
Cystine
60
21st amino acid
Selenocysteine
61
Aliphatic amino acids
LIVAG
Leucine
Isoleucine
Valine
Alanine
Glycine
62
The only achiral
R group is H
Smallest amino acid
Glycine
63
R group is methyl
Alanine
64
Also known as branched chain amino acids
Valine
Leucine
Isoleucine
65
R group is isopropyl
Valine
66
R group is isobutyl
Leucine
67
R group is secbutyl
Isoleucine
68
Amino acids with alcohol
Serine
Threonine
69
Acidic amino acids
Double COOH
Aspartic Acid
Glutamine
70
Basic amino acids
Lysine
Arginine
Histidine
Cysteine
Cystine
71
Guanido
Sakaguchi test
Arginine
72
Imidazole ring
Polydiazo test
Histidine
73
Sulfur containing amino acids
Cysteine
Cystine
Methionine
74
Double sulfur linkage
Cystine
75
Test for methionine
Fohls test or
Lead acetate
+ Dark matter or Black ppt
76
Aromatic amino acids
Phenylalanine
Tyrosine
77
Methylbenzene
Test is xanthoproteic test (Nitric acid)
What positive?
Phenylalanine
+yellow
78
The only phenolic amino acid
Phenol compound
Test is millons test
Tyrosine
79
Aromatic amino acids (WYF)
Tryptophan
80
Has an indole ring
Hopkins cole test `
Tryptophan
81
Known as imino acid
2ndary amino acid
Test is ninhydrin test
Proline
82
Has an -OH group
Secondary amino acids
Hydroxyproline
83
Under proper conditions amino acids can bond together to produce an
Unbranched chain of amino acids
84
Name of the bond between amino acids and
Peptides
85
Bond between two amino acids
Dipeptide
86
Bond between 10-20 amino acids
Oligopeptide
87
Bond between large number of amino acid
Polypeptide
88
Every peptide has a
N-terminal end and a c-terminal end
89
The number of isomeric peptides possible increases rapidly as the length of the
Peptide chain increases
90
Small peptides are biochemically active
Hormones
Neurotransmitter
Antioxidants
91
Best known peptide hormone
Oxytocin
92
Known as the love hormone
Can cause uterine contraction during labor when a woman is about to give birth to her child
Oxytocin
93
Vasopressin which controls amount of water in the urinary tract
Anti diuretic hormone or ADH
94
Oxytocin and ADH are produced by which gland
Pituitary gland
95
(Nine amino acid residues) with six of the residues held in the form a loop by a disulfide bond between two cysteine residues
Nonapeptide
96
Biochemically important small peptides
Small peptide neurotransmitters
Pentapeptide
Glutathione
97
They are pentapeptide (5) neurotransmitters produced by the brain and bind receptors within the brain
Also helps reduce pain
Enkephalins
98
Best known enkephalins
Met-enkephalin
Leu-enkephalin
99
Tyr-Gly-Gly-Phe-Met
Met-enkephalin
100
Tyr-Gly-Gly-Phe-Leu
Leu-enkephalin
101
A tripeptide
Present is in high levels in most cells
Regulator of oxidation-reduction reactions
Glutathione
102
Glu-Cys-Gly
Glutathione
103
An antioxidant and protects cellular contents from oxidizing agents such as peroxides and superoxides
Highly reactive forms of oxygen often generated within the cell in response to bacterial invasion
Glutathione
104
General definition
A protein is a naturally occuring unbranched polymer in which the monomer units are amino acids
105
Specific definition
A protein is a peptide in which at least 40 amino acid residues are present
106
Common proteins contain
400-500 amino acid residues
107
small proteins contain
40-100 amino acid residues
108
Several proteins with _____ amino acid residues are known
>10,000
109
Contains one peptide chain
Monomeric protein
110
Contains more than one peptide chain
Multimeric protein
( protein subunits)
111
A protein in which only amino acid residues are present
Simple proteins
112
A protein that has one or more non-amino acid entities (prosthetic groups) present in its structure
Conjugated proteins
113
Contain lipid prosthetic groups
Lipoproteins
114
Contain carbohydrate groups
Glycoprotein
115
Contain a specific metal as prosthetic group
Metalloproteins
