Amino Acids and Proteins Flashcards
(110 cards)
1
Q
Plasma proteins are the most commonly analyzed proteins and can be divided into 2 major groups:
A
Albumin
Globulins
2
Q
It migrates before albumin in classic serum protein electrophoresis (SPE)
A
Prealbumin or transthyretin
3
Q
It is a transport protein for the thyroid hormones, thyroxine, and triiodothyronine.
A
Prealbumin or transthyretin
4
Q
Prealbumin has a half-life of approximately ___.
A
2 days
5
Q
It is synthesized in the liver at the rate of 9 to 12 g/day and it is the most abundant protein in the plasma.
A
Albumin
6
Q
Albumin is a _____ acute pjase reactant
A
Negative
7
Q
Primary function of albumin is?
A
Its capacity to bind and transport various substances in the blood.
8
Q
Represents trends in blood glucose over a period of 3 months or approximately 120 days.
A
Glycated Hemoglobin
9
Q
The primary site for protein synthesis is?
A
Liver
10
Q
Absence of albumin in known as
A
Analbuminemia
11
Q
Presence of albumin that has unusual molecular characteristics is referred to as?
Demonsrrated by the presence of two albumin bands instead of a single one during electrophoresis
A
Bisalbuminemia
12
Q
- a glycoprotein synthesized in the liver.
- its main function is in the inhobition of the protease, neutrophil elastase.
- positive acute-phase reactant
A
a1-antitrypsin
13
Q
Mutations in the ______ gene can lead to a deficiency of a1-antitrypsin protein or an abnormal form of the protein that does not properly control neutrophil elastase
A
SERPINA1 gene
14
Q
Quantitative methods used to confirm a1-antitrypsin deficiency are (2)
A
Radial immunodiffusion
Automated immunonephelometric assays
15
Q
- is synthesized in utero by the developing embryo and fetus and then by the parenchymal cells of the liver.
- it protects the developing fetus from immunologic attack by the mother.
- reaches adult concentration at 8-12 months.
A
a1-Fetoprotein (AFP)
16
Q
AFP screening is performed between ___ and _____ weeks of gestations when maternal AFP gradually increases; therefore,interpretation requires accurate dating of pregnancy.
A
15-20 weeks
17
Q
The methods commonly used in AFP determination is (2)
A
Radioimmunoassay (RIA)
Enzyme-labeled Immunoassay (EIA)
18
Q
AFP may also be used as a tumor marker and is fractionated by affinity electrophoresis into three isoforms (L1, L2, and L3) based on their reactivity with the lectin _______.
A
Lens culinaris agglutinin (LCA)
19
Q
It is now being considered as a tumor marker for the North American population for screening chronic liver disease patients for hepatocellular carcinoma (HCC)
A
AFP-L3
20
Q
- is a major plasma glycoprotein that is negatively charged even in acidic solutions lending to its name.
- produced by the liver and is a positive acute-phase reactant.
- serum _____ concentrations are also used in the diagnosis and evaluation of neonatal bacterial infections.
A
a1-Acid glycoprotein (AAG) or orosomucoid
21
Q
The analytic methods used most commonly for the determination of AAG are (3)
A
Radial immunodiffusion
Immunoturbidity
Nephelometry
22
Q
- is an a-globulin glycoprotein that is a member of the serine proteinase inhibitor (serpin) family.
- it inhibits the activity of the enzymes cathepsin G, pancreatic elastase, mast cell chymase, and chymotrypsin by cleaving them into a different shape (conformation).
- produced in the liver and is a positive acute-phase reactant that increases during inflammation.
A
a1-Antichymotrypsin
23
Q
- are a family of serine protease inhibitor l, assembled from two precursor proteins: a light chan and one or two heavy chains.
- have been shown to play a particular role in inflammation and carinogenesis.
A
Inter-a-Trypsin inhibitor
24
Q
- is also known as a group-specific component or vitamin D-binding protein.
- synthesized by the hepatocytes and is the mahor carrier protein for vitamin D and its metabolites.
- it also transports components such as fatty acids and endotoxins.
A
Gc-globulin
25
- The resulting decrease in ____ concentration makes it usable as a prognostic indicator of survival of patients with significant tissue injury after trauma and among patients with hepatic failure.
-it may be of importance for bone formation and in the immune system.
Gc-Globulin
26
What is the method of choice for Gc measurements?
Immunonephelometry
27
- it is an a2-glycprotein synthesized in the liver and is a tetramer consisting of two a and two b chains.
- its primary function is to bind free hemoglobin to prevent the loss of its constituent, iron, into the urine.
- it is a positive acute-phase reactant that increases in many inflammatory diseases, such as ulcerative colitis, acute rheumatic disease, acute myocardial infarction, and severe infection.
Haptoglobin
28
Quantitative determination for haptoglobin (2)
Radial immunodiffusion
Immunonephelometric methods
29
- is a copper-containing, a2-glycoprotein enzyme that is synthesized in the liver.
- it is a positive acute-phase reactant and is frequently elevated in inflammation, severe infection, and tissue damage and may be increased with some cancers.
Ceruloplasmin
30
Ceruloplasmin is primarily measured along with blood and urine copper test to aid in the diagnosis of?
Wilson's disease
31
The analytic method of ceruloplasmin determination was based on its _______ activity. Most assays today use immunochemical methods including (2)
Copper oxidase activity
Radial immunodiffusion
Nephelometry
32
- is a tetramer of four identical subunits that is synthesized by the liver and is a major component of the a2-band in protein electrophoresis.
a2-Macroglobulin
33
Analytic methods used for measurement of a2-macroglobulin are (4)
Radial immunodiffusion
Immunonephelometry
Enzyme-linked immunosorbent assay (ELISA)
Latex agglutination immunoassay
34
- is a negative acute-phase glycoprotein synthesized by the liver.
- it is a major component of b-globulin fraction on protein electrophoresis and plays an important role in the transport of iron.
- it also carries iron to other sites, such as the bone marrow, that synthesize hemoglobin and other iron-containing compounds.
Transferrin or siderophilin
35
____ prevents iron from being inappropriately deposited in tissues during temporary increases in absorbed iron or free iron.
Transferrin
36
An increase of iron bound to transferrin is found in hereditary disorder of iron metabolism, known as ______ in which excess iron is deposited in the tissue, especially in the liver and the pancreas l.
hemochromatosis
37
It is inherited as an autosomal recessive trait due to mutation of both transferrin genes, with a resulting absence of transferrin.
Atransferrinemia
38
Analytic methods used for the quantitation of transferrin (2)
Immunodiffusion
Immunonephelometry
39
Total serum iron is low, but TIBC is increased, and transferrin saturation becomes very low.
Iron deficiency
40
Total serum iron is high and TIBC is low or normal, causing transferrin saturation to increase.
Iron overload
41
- the parenchymal cells of the liver synthesize ____, which migrates electropheretically in the b-globulin region and is an acute-phase reactant.
- its main function is to bind with free heme.
Hemopexin
42
Heme-hemopexin complex is carried to the liver and has a ration of?
1:1
43
Hemopexin determinations are performed by?
Radial immunodiffusion
44
Are complexes of proteins and lipids whose function is to transport cholesterol, triglycerides, and phospholipids in the bloodstream.
Lipoproteins
45
In high-resolution electrophoresis, HDL migrates between the?
Albumin and a1-globulin zone
46
In high-resolution electrophoresis, VLDL migrates at the?
Beginning of b-globulin fraction (pre-b)
47
In high-resolution electrophoresis, LDL appears as?
A separate band in the b-globulin region
48
It is the light chain component of the major histocompatibility complex or human leukocyte antigen (HLA)
b2-Microglobulin (B2M)
49
B2M is usually measured by?
Immunoassay
50
- is a natural defense mechanism that protects the human body from infection.
- these proteins are synthesized in the liver as a single polypeptide chains and circulate in the blood as nonfunctional precursors.
Complement system
51
Complement ______ is the most abundant complement protein in the human serum, with complement ______ being the second abundant
C3; C4
52
Methods measuring complements include (2)
Nephelometric immunoassay
Turbidimetry
53
- it is one of the largest proteins in the blood plasma.
- it is synthesized in the liver and classified as a glycoprotein.
- it is a positive acute-phase reactant and increases significantly during an inflammatory process.
Fibrinogen
54
- it is synthesized in the liver and is one of the first acute-phase proteins to rise in response to inflammatory disease.
C-reactive protein (CRP)
55
CRP is generally measured by immunologic methods including (2)
Nephelometry
EIA
56
- is the C-reactive protein, but is named for a monoclonal antibody-based test methodology that can detect CRP levels below 1mg/L.
- most commonly used to determine risk of CVD.
High-sensitivity CRP (HsCRP)
57
- are glycoproteins composed of 82% to 96% protein and 4% to 18% carbohydrate.
- produced by white blood cells known as B cells.
Immunoglobulins or antibodies
58
Immunoglobulins: the N-terminal regions of the heavy and light chains exhibit highly variable amino acid composition referred to as VH and VL, respectively. This variable region is involved in?
Antigen binding
59
The constant domains of light and heavy chains are referred to as CL and CH, respectively. The constant regions are involved in?
Comolement binding
60
Is a biologic mechanism that changes an antibody from one class to another.
Immunoglobulin class switching or isotype switching
61
Immunoglobulins have been determined using (5)
Radial immunodiffusion
Nephelometry
Turbidimetry
Electrochemiluminescent immunoassay (ECLIA)
RIA
62
- is a single-chain globular protein of 153 amino acids, containing a heme prosthetic group.
- it is the primary oxygen-carrying protein found in striated skeletal and cardiac muscle, accounting for approximately 2% of total muscle protein.
Myoglobin
63
It can reversibly bind oxygen similarly to the hemoglobin molecule, but _______ requires a very low oxygen tension to release the bound oxygen.
Myoglobin
64
What are the most commonly used methods for myoglobin measurements? (5)
Latex agglutination
ELISA
Immunonephelometry
ECLIA
Fluoroimmunoassay
65
Represents a complex of regulatory proteins that include troponin C (TnC), troponin I (cTnI), and troponin T (cTnT) that are specific to cardiac muscle.
Cardiac troponin
66
Are considered the "gold standard" for diagnosis of acute coronary syndrome (ACS) in which the blood supply to the heart muscle is suddenly impeded.
Cardiac troponin
67
Cardiac troponins can be measured using (2)
ELISA
Immunoenzymometric assay
68
Are a family of structurally related hormones that include atrial natriuretic peptide (ANP), B-type (or brain) natriuretic pepdtide (BNP), C-type natriuretic peptide (CNP), and Dendroaspis natriuretic peptide (DNP).
Natriuretic peptides
69
Are neurohormones that affect body fluid homeostasis, through natriuresis and diuresis, and blood pressure, through decreased angiotensin II and norepinephrine synthesis.
Natriuretic peptides
70
Laboratory methods for measuring BNP and NT-proBNP include (3)
RIA
Microparticlr enzyme immunoassay (MEIA)
ECLIA
71
- is a glycoprotein composed of two nearly identical subunits.
- these proteins are found in plasma and on cell surfaces and can be synthesized by hepatocytes, endothelial cells, and peritoneal macrophages, abd fibroblasts.
Fibronectin
72
It is used to help predict the short-term risk of premature delivery.
Fetal fibronectin
73
Is a 247-amino acid hormone composed of an N-terminal collagen-like domain and a C-terminal globular domain produced by adipocytes.
Adiponectin
74
- is a 168-amino acid, low-molecular-mass protein in the lipocalin protein family.
- established as an accurate marker of cerebrospinal fluid leakage and have also been used as a potential marker in detecting impaired renal function through BTP is no more sensitive than custatin C.
B-trace protein (BTP) or prostaglandin D synthase
75
- are proteolytic fragments of collagen I formed during bone turnover, and their presence in serum and urine is a biochemical marker of bone resorption.
- useful in monitoring response to antiresorptive therapy as it is noninvasive and can be repeated often.
Cross-linked C-telopeptides(CTXs)
76
What method is used for CTX measurement?
ECLIA
77
- a low molecular-mass protein with 120-amino acids, is a cysteine proteinase inhibitor.
- it is freely filtered by the glomerulus and almost completely reabsorbed and catabolized by the proximal tubular cells.
Cystatin C
78
Cystatin C measurements may be performed by (2)
Particle-enhanced immunoturbidimetric or immunonephelometric methods
79
Are insoluble fibrous protein aggregates formed due to an alteration in their secondary structure known as b-pleated sheets.
Amyloid
80
Refers to conditions in which amyloids are abnormally deposited in organs and tissues, including the heart and blood vessels, brain and peripheral nerves, kidneys, liver, spleen, and intestines, causing localized or widespread organ failure.
Amyloidosis
81
A total protein concentration below the reference interval, occurs in any condition where a negative nitrogen balance exists.
Hypoproteinemia
82
An increase in total plasma proteins, is not associated with disease state, but is commonly the result of dehydration.
Hyperproteinemia
83
A total nitrogen determination measures all chemically bound nitrogen in the specimen and can be performed on various sample types, but is most commonly performed using?
Plasma
84
The most common method for total nitrogen analysis uses?
Chemiluminescence
85
The specimen most used to determine totak protein concentration is?
Serum
86
Total protein methods: the classic method for quantitation of total protein is the ____ method, which measures the amount of nitrogen in the specimen.
- this method is no longer routinely used in the clinical lab because it is time consuming and relies on some assumptions that are not always true
Kjeidahl method
87
Total protein methods: is the most widely used method for the determination of total protein and is recommended by the International Federation of Clinical Chemistry expert panel.
Biuret
88
Total protein methods: based on the ability of most serum proteins to bind dyes, although the affinity with which they bind may vary.
Dye binding
89
Globulins are separated from the albumin by a precipitation process using sodium salt
Salt fractionation
90
The most widely used method for determining albumin are?
Dye-binding procedures
91
Building blocks of protein
Amino acids
92
The amino group of one amino acid can be linked with the carboxyl group of another amino acid forming a?
Peptide bond
93
When a chain of amino acifs is linked by peptide bonds, it known as?
Polypeptide
94
A large polypeptide constitutes a?
Protein
95
What are the essential amino acids? (10)
Arginine
Histidine
Isoleucine, Leucine, Valine
Lysine
Methionine
Phenylalanine
Threonine
Tryptophan
96
What do you mean by essential amino acids
97
- is a complex amino acid often found at the catalytic (active) site in proteins and enzymes due to its amine-containing side chain.
- plays an important role in cell division, wound healing, stimulation of protein synthesis, immune function, and release of hormones.
- one important role is the conversion of ammonia into urea.
Arginine (Arg)
98
- one of the basic by pH amino acids due to its imidazole side chain.
- needed to help grow and repair body tissues and to maintain the myelin sheaths that protect nerve cells and is the direct precursor of histamine which is involved in immune response.
Histidine (His)
99
Are branched chain amino acid
Isoleucine (Ile), Leucine (Leu) and Valine (Val)
100
Branched chain amino acid group: plays an important role in hemoglobin formation
Isoleucine (Ile)
101
Branched chain amino acid group: necessary for optimal growth in infants
Leucine (Leu)
102
Branched chain amino acid group: both aid in maintaining the nitrogen valance in adults
Leucine (Leu) and Valine (Val?
103
Branched chain amino acid group: used in treatments for muscle, mental, and emotional problems such as insomnia and anxiety, as well as liver and gallbladder disease.
Valine (Val)
104
- has a net positive charge, which makes it one of three basic, by charge,
amino acids.
- It plays a role in the production of antibodies and lowering triglyceride levels.
- also helps in the absorption and conservation of
calcium and plays an important role in the formation of collagen, a component of
cartilage and connective tissue.
Lysine (Lys)
105
- is an important amino acid that helps to initiate translation of
messenger RNA (mRNA) by being the first amino acid incorporated into the Nterminal position of all proteins
- is a source of sulfur, which is
required for normal metabolism and growth
- also assists in the
breakdown of fats, helps to detoxify lead and other heavy metals, helps diminish
muscle weakness, and prevents brittle hair
Methionine (Met)
106
- is classified as a nonpolar amino acid because of the hydrophobic
nature of its benzyl side chain. It promotes alertness and vitality, elevates mood,
decreases pain, aids in memory and learning, and is used to treat arthritis and
depression.
- is used by the brain to produce norepinephrine, a
neurotransmitter that transmits signals between nerve cells
Phenylalanine (Phe)
107
- is an alcohol-containing amino acid that is an important component in
the formation of collagen, elastin (a connective tissue protein), and tooth enamel
- helps maintain proper protein balance in the body
and aids liver function, metabolism, and assimilation.
Threonine (Thr)
108
- is a metabolic precursor for serotonin, melatonin (a neurohormone),
and niacin (a vitamin).
- is a natural relaxant that helps alleviate
insomnia by inducing sleep, soothes anxiety, and reduces depression.
Tryptophan (Trp)
109
What are the nonessential amino acids? (10)
Alanine
Asparagine
Aspartic acid
Cysteine
Glutamic acid
Glutamine
Glycine
Proline
Serine
Tyrosine
110
What does it mean by nonessential amino acids
