protein functions, amino acids, peptide bonds Flashcards
actin and myosin
contractile proteins
immunoglobulins, thrombin, fibrinogen, snake venom
defense proteins
peptidase and esterase
enzymes
insulin, parathyroid hormone, growth hormone, enkephaline, dopamine
regulatory proteins
seed protein, ovalbumin, casein, ferritin
storage proteins
a-keratin, collagen, fibrin, elastin
structural proteins
hemoglobin, lipoprotein, integral protein
transport proteins
______ are polymeric substance composed of many amino acids linked together in a __________
proteins; unique sequence
_______ is determined by the unique sequence of amino acid units in the protein and its structural organization
function of a protein
proteins are major class of food needed for what?
growth and maintenance
proteins can function as _________ and _______
structural materials and enzymes
peptide chains having amino acids but no other nonprotein components
simple protein
peptide chains having amino acids and other nonprotein components
conjugated protein
lipoproteins, glycoproteins, phosphoproteins, hemoproteins
conjugated proteins
an amino acid is any molecule with at least one ____ and one ____
carboxyl (COOH) group and amino (NH2) group
the amino group must be on the carbon ____ to the -COOH to be classified as an _-amino acid
adjacent; alpha
r groups of nonpolar
alkyl, aromatic (automatically neutral)
r groups of polar
amino, hydroxyl, carboxyl, s-containing (acid, base, neutral)
four parts of an amino acid
amino (NH2-) group, a-carbon, R-variable side chain, carboxyl (-COOH) group
variable R group can contain what groups?
alkyl, aromatic, hydroxyl (-OH), amino (-NH2), cafrboxyl (-COOH), S-containing groups
formula for alkyl group
CnH2n+1
amino acids can also be classified by the number of relative ____ and ______ groups as acidic, basic, neutral
amino and carboxyl
how to determine if acidic, basic, or neutral
acidic (COOH > NH2 groups)
basic (COOH < NH2 groups)
neutral (COOH = NH2 groups)
what are the two acidic amino acids?
asp (aspartic acid) and glu (glutamic acid)
what are the three polar basic amino acids?
lys (lysine), arg (arginine), his (histidine)
required to maintain good health
essential amino acids
cannot be synthesized in the body and must be supplied from dietary protein
essential amino acids
how many essential amino acids?
ten (10)
enumerate the essential amino acids
tingnan mo na lang yung table na provided, yung mga naka-cross
either complete or incomplete based on the presence or absence of the ten essential amino acids
dietary proteins
supplies all the essential amino acids
complete dietary protein
deficient in one or more essential amino acids
incomplete dietary protein
why is corn an incomplete dietary protein?
it doesnt have lysine
are carbon atoms that are attached to ____ different substituents that are placed at the corners of a tetrahedron
chiral carbon centers; four
the alpha carbon of all amino acids is chiral
true (except glycine)
NH2 - CH (CH3) - COOH
L-(+)-alanine
COOH - CH (CH3) - NH2
D-(-)-alanine
proteins consist only of this isomer
L-amino acids
the (-) and (+) signs indicate the direction of each isomer rotates the ___________
plane-polarized light
amino acids are ____ which mean they can react as an acid or base
amphoteric
amino acids exist in neutral solutions as _______
zwitterions
a zwitterion is a _________ formed by internal transfer of a _____ from a -COOH group to a -NH2 group
dipolar ion, proton
zwitterions and other prortein molecules act as ______ to maintain the blood pH at ___
buffers; 7.4
an amino acid in solution can have either an ___ or ___ number of positive and negative charges
equal or unequal
ratio of electrical charges is ___
pH dependent
when the ratio of positive to negative charges of an amino acid is one, the molecule is electrically _______ and does not migrate to the cathode or anode of an electrolytic cell
neutral
pH where amino acid is electrically neutral is what?
isoelectric point
a ______ is an amide bond that is formed when a –COOH group of one amino acid reacts with the a-amino group (-NH2 ) of a different amino acid
peptide bond or peptide linkage
start codon
AUG
stop codon
UAG, UAA, UGA
a _______ is a molecule that contains two or more amino acid residues linked together by ________
peptide; peptide bond/linkage
the type of peptide is often referred to by the _____ of residues in the chain or as a _____ if the number of residues is less than 40-50 units
number; polypeptide
two residues, three residues, four residues, etc.
dipeptide, tripeptide, tetrapeptide
a __________ will have one end with a free –NH2 group and another end with a free –COOH group
linear peptide
The end of the polypeptide chain with the –NH2 group is called the ______ while the end with the –COOH group is called the ________
N-terminal residue and C-terminal residue
if the sequence is not know, what do we place?
parentheses
peptides are named as _______ of the C-terminal amino acid and the C-terminal amino acid retains its complete name
acyl derivatives
the specific biological action of a polypeptide is controlled by the _________ and __________
length of the polypeptide chain and the amino acid sequence
many naturally occurring polypeptides like oxytocin and vasopressin act as _____
hormones
pain producing agent
substance p
relieves pain, produces sense of well-being
enkephalin
increases blood pressure
vasopressin
childbirth labor, milk release, affects kidney excretion
oxytocin
cause wakefulness
orexin
acts as a morphine-like analgesic
endomorphin
stimulates eating
neuropeptide Y
brain memory function
neurotensin
modulates pain sensations
neuropeptide FF
maintains water balance and blood pressure
angiotensin II
affects tissue inflamation and blood pressure
bradykinin
