amino acids Flashcards
protein:
Greek word, “???,” meaning prim
proteios
proteins Make up ??? of total dry body weight
3/4th
protein:
Contain the major components of ??? while ?? and ?? minor components
C,H,O, N;
S and P
proteins are distinguished by
nitrogen
protein Commonly contain ?? types of amino acids
20
roles of proteins (7)
digestive enzyme
transport
structure
hormone signaling
defense
contraction
storage
examples: digestive enzyme
amylase
lipase
pepsin
example: transport proteins
hemoglobin
examples: structure protein
actin
tubulin
keratin
examples: hormone signaling protein
insulin
glucagon
examples: defense protein
antibodies
examples: contraction protein
myosin
examples: storage protein
legume storage proteins
egg white (albumin)
The building blocks of proteins
amino acids
amino acids are also used as single molecules in ???
biochemical pathways
Two functional groups: amino acids
➢ carboxylic acid group
➢ amino group on the alpha carbon
amino acids have different side groups (R)
➢ ??? dictate behavior of amino acids
➢ Structure of R also influence ???
Properties;
solubility
Both the –NH2 and the –COOH groups in an amino acid undergo ??? in water
ionization
At physiological pH (7.4), a ??? forms
➢ Both + and – charges
➢ Overall neutral
➢ ???
▪ Amino group is ???
▪ Carboxyl group is ???
zwitterion;
Amphoteric;
protonated;
deprotonated
are compounds that can act as both acids and bases.
Amphoteric substances
amino acids are soluble in polar solvents due to ???
ionic character
The α carbon is chiral or asymmetric ( 4 different
groups are attached to the carbon; exception is ???)
glycine
Amino acids exist as ??? (same molecular formula, but differ in arrangement of groups).
stereoisomers
Amino acids used in nature are of ??? configuration
L
NH3 + on left =
L
NH3 + on right =
D
called α -amino acids because they all have:
- an amino (NH3+) group
- a carboxyl group (COOH) attached to C-2 carbon (α -carbon).
Classify by structure of R [amino acids] (5)
– Nonpolar
– Polar
– Aromatic
– Acidic
– Basic
NON POLAR ALIPHATIC AMINO ACIDS (7)
Proline
Glycine
Alanine
Valine
Leucine
Isoleucine
Methionine
polar, uncharged r groups (6)
Serine
Threonine
Cysteine
Asparagine
Glutamine
Tyrosine
Positively charged R groups (3)
lysine
arginine
histidine
negatively charged R groups (2)
aspartate
glutamate
nonpolar, aromatic R groups (3)
phenylalanine
tryptophan
tyrosine
All amino acids (except ???) are optically active
glycine
