Amino Acids Flashcards
amino acids consist of what 4 groups connected to the central alpha carbon?
amino group, carboxyl group, R side chain, hydrogen bond
NH2 is what type of group?
amino
COOH is what type of group?
carboxyl
At physiological pH, amino group is _____ and looks like NH3+
protonated
At physiological pH, the carboxyl group is _________ and looks like COO-
unprotonated
The R side chain, amino group, hydrogen, and carboxyl group and bounded by what type of bond?
covalent
How many nonpolar/hydrophobic amino acids are there?
8
ALA, A
alanine
VAL, V
valine
LEU, L
leucine
ILE, I
isoleucine
PRO, P
proline
MET, M
methionine
PHE, F
phenylalanine
TRP, W
tryptophan
alanine is a ___ amino acid
nonpolar/hydrophobic
valine is a _____ amino acid
nonpolar/hydrophobic
leucine is a ____ amino acid
nonpolar/hydrophobic
isoleucine is a ____ amino acid
nonpolar/hydrophobic
proline is a ____ amino acid
nonpolar/hydrophobic
methionine is a ____ amino acid
nonpolar/hydrophobic
phenylalanine is a ____ amino acid
nonpolar/hydrophobic
tryptophan is a _____ amino acid
nonpolar/hydrophobic
alanine has a ____ R chain
short
valine has a ____ R chain
short
leucine has a ____ R chain
short
isoleucine has a ____ R chain
short
phenylalanine has a _____ R chain
ring structure
tryptophan has a _____ R chain
6 side ring fused to a 5 side N structure
proline has a ____ R chain
unique cyclic
methionine has a ____ R chain
sulfur containing
There are _____ polar amino acids
8
glycine is a _____ amino acid
polar
serine is a _____ amino acid
polar
threonine is a _____ amino acid
polar
tyrosine is a _____ amino acid
polar
cysteine is a _____ amino acid
polar
asparagine is a _____ amino acid
polar
glutamine is a _____ amino acid
polar
histidine is a _____ amino acid
polar
glycine has a ____ R group
simplest, H
serine has a ____ R group
hydroxyl (OH)
OH is what kind of group?
hydroxyl
threonine has a _____ R group
hydroxyl (OH)
tyrosine has a ____ R group
hydroxyl (OH)
cysteine has a ____ R group
sulfur containing
asparagine has a ____ R group
amide (NH2)
glutamine has a ____ R group
amide (NH2)
histidine has a _____ R group
amide
____ is unique in that at pH above or at 7 it has normal structure but at pH below 7, the second nitrogen binds to an extra H+ and gives the R side chain a positive charge
histidine
The sulfur R side chain group on cysteine is ____ reactive
highly
What are the 2 acidic amino acids (have net neg charge at pH 7)
aspartic acid, glutamid acid
How many acidic amino acids are there?
2
the acidic amino acids what a ____ R group
carboxyl (COOH)
What are the 2 basic amino acids (net pos charge at neutral pH)?
lysine, arginine
the basic amino acids have a ____ R group
positively charged nitrogen group
Hydroxylysine is a modified _____ found in _____
lysine, collagen
Hydroxylysine has an added _____ compared to lysine
OH
Acetyllysine is a modified ____ found in ____ ______
lysine, histone proteins
thyroxine is 2 ______ and is found in ___ _____
tyrosines, thyroid hormone
Thyroxine has added ___ _____ and lost other atoms
4 iodines
Carboxyglutamic acid is modified ____ involved ____ _____
glutamic acids, blood clotting
Carboxyglutamic acid has added 2 _____ ______
carboxyl groups
Carboxyglutamic acid is found with the protein in blood clotting factors to ____ them
activate
Acetyllysine has an added _____ linked through the amino group
acetyl
Acetyllysine allowed for _____ _______ and the modification is later removed to allow histones to rebind to DNA
DNA seperation
Acetyllysine ______ lysine to allow for DNA strand seperation
neutralized
The cationic form of amino acids is at a ___ pH
low
the _____ group is neutral when the amino acid is in cationic form
carboxyl
the ____ group is positively charged when the amino acid is in cationic form
amino
the ____ bound hydrogen is released when going from cationic form to zwitterion (neutral)
weakly bound
The ____ group is negatively changed when the amino acid is in neutral/zwitterion form
carboxyl
The ____ group is positively changed when the amino acid is in neutral/zwitterion form
amino
The ____ group is negatively changed when the amino acid is in anionic form
carboxyl
The ____ group is neutral when the amino acid is in anionic form
amino
The amino acid is in ____ form when the pH is high
anionic
The 1 positive and 1 negative charged group on the zwitterion atom makes it ______ (they cancel out)
neutral
The net charge is _____ in the cationic form
positive (+1)
The net charge is _____ in the anionic form
negative (-1)
The overall charge of the amino acid is highly sensitive to _____
pH
The most important reaction of amino acids is making a ________ _________
peptide bond
A peptide bond is formed by the reaction of the ____ group of one amino acid and the _____ group of another
carboxyl (COO-), amino (NH3+)
The reaction of forming a peptide bond results in the creation and loss of a ____ molecule
water
CO-NH is a ____ bond
peptide/amide
The result of a peptide bond formation has a ____-terminal end and a ____-terminal end
N, C
The formation of a ____ ______ aides in the folding of protein chains, helps form loops, and stabilizes the 3D protein structure
disulfide bridge
What are the three terms for having two possible configurations?
mirror-image isomers, enantiomers, chiral
All proteins are naturally found in the ____ configuration
L
The two mirror images are the ___ form and the ____ form
L (left/levo), D (dextro/right)
The lab technique of separating amino acids or proteins is ___ ____ _______
ion exchange chromatography
The ___ _____ charged amino acid is eluted first in the ion exchange chromatography
least positively
The bead used in ion exchange chromatography is ___ charged
negatively
The amino acid that can form a disulfide bridge is ______
cysteine
If a protein is X amino acid residues in length, how many different amino acid sequences are possible?
20^X
