Amino Acids and Proteins (Module 6) Flashcards
organic molecules with at least one _______ group (basic -NH2) and one ______ group (acid –COOH)
Amino
Carboxyl
_- form isomers most common in humans
L
amino acids are ___________(can act as acids or bases)
at alkaline ph (high), have a net ____ charge
at acid pH (low), have a net ___ charge
ampholytes
neg
pos
polypeptides with >___amino acids are called proteins
50
Simple
contain only ______ ______
eg: albumin, ______
Amino Acids
Collagen
Derived- protein breakdown products
- ________, ________
peptides
peptones
contain a non-protein prosthetic group which relates to the function of the protein
Conjugated protein
Sequence of amino acids linked together by peptide bonds in a polypeptide chain
Primary Structure
Shaping of polypeptide chain by hydrogen bonds.
either a alpha-helix (most common) or a beta-pleated sheet
Secondary Structure
folding of polypeptide chain into a characteristic three dimensional shape.
held together by hydrogen, covalent and ionic bonds, as well as hydrophobic forces
Tertiary Structure
association of various subunits (folded polypeptides) to produce a specific macromolecule.
eg four globin chains to make a hemoglobin molecule
Quaternary Structure
the pH of a solution where the protein will have a net charge of zero (neutral)
Isoelectric Point (pI)
most plasma proteins have a pI around _ or _
negatively charged at normal pH ____
4 or 5
7.4
breakage of bonds in the secondary and tertiary structures.
changes functionality of protein
may or may not be reversible
Denaturation
disruption of bonds in primary structure.
irreversible
Coagulation
Stomach
Parietal cells- release _________ ______
Chief cells- release _______ -> _____
hydrochloric acid
trypsinogen and chymotrypsinogen
Removal of amino group (-NH2) to produce an α-keto acid and ammonia
Deamination
Transfer of an amino group from one amino acid to an α-keto acid to produce a different amino acid (and new α-keto acid)
Transamination
Transamination
catalyzed by aminotransferases, give two examples
AST and ALT are found in high levels in ____, _______, _________
aminotransferases
aspartate aminotransferase (AST) alanine aminotransferase (ALT)
liver, heart and skeletal muscle tissue
reaction of peptide bonds of proteins with copper ions at an alkaline pH.
violet color produced proportional to the number of peptide bonds (=amount of protein)
Biuret Method for Total Protein
__________ ____- prevents autoreduction of cupric ions
(Cu2+ Cu+)
_____ _________ _______- maintains cupric ions in solution at alkaline pH
potassium iodide
sodium-potassium-tartrate
What are two tests that the biuret method is not used for?
NOT used for urines (ammonia interferes) or for CSF proteins (not sensitive enough for low levels)
specific dyes will selectively bind to proteins:
Albumin: __________ or _________
Urine proteins: __________ ______ _______
Electrophoresis: _______ ________, _______ _____
bromocresol green (BCG) or bromocresol purple (BCP)
Coomassie Brilliant Blue
Amido black, Acid violet
Reference Ranges
Total Protein __– __ g/L
Albumin __ – __ g/L
60-80
35-55
high ionic strength= ____ resolution
lower mobility gives higher resolution (distinct bands), but are crowded together
low ionic strength= ___ resolution
higher mobility separates bands over larger area, but are more diffuse and less distinct
high
low
Movement of buffer in the direction _______ to protein migration
opposite
slowest moving proteins (gamma) will be swept backwards towards _____- (_______migration)
cathode
Cathodic
Ohms Law =
E=I X R
voltage=current x resistance)
Albumin is ________ moving, so farthest migration towards anode.
Gamma globulins display _________ migration from point-of-application (POA) due to electroendosmosis
fastest
cathodic
What are two functions of albumin?
transport- bilirubin, hormones, calcium, magnesium, fatty acids, uric acid
regulation of osmotic (oncotic) pressure between plasma and interstitial fluid
What does alpha-antitrypsin do?
Neutralizes proteases
What does Alpha lipoproteins do?
high density lipoproteins (HDL) for transport of cholesterol and fat-soluble vitamins
What does thyroid binding globulin do?
transport of thyroid hormones in blood
What does alpha fetoprotein do?
present in fetal serum, infants and pregnant females
What does haptoglobin do?
binds free hemoglobin in plasma
what does ceruloplasmin do?
transport of copper in plasma
what does alpha2-macroglobulin do?
binds and inhibits proteases
largest portion of α2 band
what does Pre-beta-lipoproteins do?
very low density lipoproteins
what does VLDL do?
transport of cholesterol
what does transferrin do
iron transport
what does hemopexin do
heme binding
what does β2-microglobulin do
HLA complex on cell surfaces
what does C3 and C4 do
complement components
what does CRP- C-reactive protein do
(opsonization)
IgA- broad bridge (β-γ bridging)
__________ in liver disease
increased
What does the Gamma band contain?
diffuse band of immunoglobulins (IgG, IgM, IgD and IgE)
excessive loss
nephrotic syndrome, burns, blood loss
decreased intake
diet, malnutrition
liver disease
immunodeficiency disorders
accelerated protein breakdown
muscular dystrophy, burnsHypoproteinemia
Albumin \_\_\_\_\_\_\_\_\_: dehydration \_\_\_\_\_\_\_\_\_: liver disease nephrotic syndrome acute phase reactions malnutrition/starvation
Increased
Decreased
α1 -antitrypsin
_________: inflammation
_________: emphysema
increased
decreased
α1- lipoprotein (HDL)
__________: hyperlipidemia
__________: liver disease
increased
decreased
α1- fetoprotein
_______: pregnancy, neural tube defects (spina bifida), primary liver cancer
increased
haptoglobin
_______: inflammation, Hodgkin’s, AMI
________: hemolytic anemia, liver disease
increased
decreased
ceruloplasmin
_________: pregnancy
_________: Wilson’s disease
increased
decreased
α2 - macroglobulin
________: nephrotic syndrome
________: multiple myeloma
increased
decreased
transferrin
_________: anemias
_________: nephrotic, liver disease
increased
decreased
β2-microglobulin
________: renal failure, inflammation, lymphocyte disorders
increased
β lipoproteins (LDL)
_______: hyperlipidemia
increased
C reactive protein (CRP)
_________: atherosclerosis, inflammation
increased
the gamma band increases when there are ______ and ____ _____
infections
liver disease
Sharp bands appear in the gamma band when there is _____ ______
multiple myeloma
the gamma band decreases when there is ______ _____ and _____ _____
immune deficiencies
lymphocytic leukemia
when a group of proteins produced by liver that increase when there is inflammation, infections and trauma.
Acute phase proteins
