FINAL TERM Flashcards
(140 cards)
Class of Protein
Structural, Contractile, Transport, Storage, Hormone, Enzyme, and Protection
Class of Protein that regulate body metabolism and nervous system
Hormone
Class of protein that catalyze biochemical reactions in the cells
Enzyme
Class of protein that recognizes and destroy foreign substances
Protection
-are the building blocks of proteins
-contain a carboxylic acid group and an amino group
-on the alpha (α) carbon
-are ionized in solution
-each contains a different side group (R)
Amino acids
Types of Amino acids
Polar, nonpolar, acidic, and basic
Type of amino acids with hydrocarbon
side chains (hydrophobic)
-has an R group that is H, an
alkyl group, or aromatic.
Nonpolar
Type of amino acids with polar
or ionic side chains
(hydrophilic)
-has an R group that is alcohol,
thiol, or amide.
Polar (neutral)
Type of amino acids with
–NH2 side chains
(hydrophilic)
-with an amino R group (NH3+)
Basic
-are chiral except glycine, which has two H atoms
-attached to the alpha carbon atom
-have Fischer projections that are stereoisomers
-that are L isomers are used in proteins
Amino acids
-has an equal number of —NH3+ and COO– groups
-forms when the H from —COOH in an amino acid
transfers to the —NH2
Zwitterion
-are the pH at which zwitterions
have an overall zero charge
-of nonpolar and polar (neutral)
amino acids exist at pH values
from 5.1 to 6.3
Isoelectric points (pI)
the zwitterion accepts a proton
(H) to form a positively charged ion.
Acidic solution
-In solutions that are more acidic than the pI,
-the COO– in the zwitterion accepts a proton
-the amino acid has a positive charge
Zwitterions in Acidic solutions
-In solutions that are more basic than the pI,
-the NH3+ in the zwitterion loses a proton
-the amino acid has a negative charge
Zwitterions in basic solutions
the -NH3+ of the zwitterion loses a
proton, and a negatively charged species is formed.
Basic solution
-a polar (acidic) amino acid,
-has a pI of 2.8
-forms a zwitterion at pH 2.8
-forms negative ions with charges 1– and 2– at pH
values greater than pH 2.8
Aspartic acid
-an electric current is used to
separate a mixture of amino acids, and
-the positively charged amino acids move toward the
negative electrode
-the negatively charged amino acids move toward the
positive electrode
-an amino acid at its pI does not migrate
-the amino acids are identified as separate bands on the
filter paper or thin layer plate
Electrophoresis
-is an amide bond
-forms between the carboxyl group of one amino acid
and the amino group of the next amino acid
-contains an N (free H3N+) terminal written on the left
-contains a C (free COO –) terminal written on the right
Peptide bond
-a yl ending for the N-terminal (free H3N+) amino acid
-the full amino acid name of the free carboxyl group
(COO–) at the C-terminal end
Dipeptide
The primary structure of a protein is
-the particular sequence of amino acids
-the backbone of a peptide chain or protein
-have similar primary structures
-differ only in the amino acids at positions 3 and 8
Nonapeptides oxytocin and vasopressin
-was the first protein to have
its primary structure
determined
-has a primary structure of
two polypeptide chains
linked by disulfide bonds
-has an A chain with 21
amino acids and a B chain
with 30 amino acids
Insulin
-a coiled shape held in place by hydrogen bonds
between the amide groups and the carbonyl groups
of the amino acids along the chain
-hydrogen bonds between the H of an —NH group
and the O of C═O of the fourth amino acid down
the chain
Alpha helix (α-helix)