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Chapter 11&12

Terms in this set (73)

Amino acids
Are the building blocks of proteins and
A single amino acid contains
At least one one amino group and one carboxyl group
Peptide bond
When the amino group of one amino acid can be linked with the carboxyl group of another amino acid
Polypeptides
When a chain of amino acids is linked by a peptide bond
Protein
A large polypeptide
How many amino acids are required by humans for protein synthesis
20
Under normal circumstances proteolytic enzymes
Such as pepsin and trypsin completely digest dietary proteins into their constituent amino acids
What are some examples of conjugated proteins?
HDL, hemoglobin, ceruloplasm
Haptoglobin
Functions to transport free hemoglobin in the plasma to the reticuloendothelial system
What are examples of acute phase reactants?
C-reactive proteins, fibrinogen, alpha 1 antitrypsin, haptoglobin
The proteins that are most frequently analyzed in the clinical chemistry lab are
Plasma/serum
Prealbumin is a sensitive indicator of nutritional status because
It has very short half life and decreases more rapidly than other proteins
Alpha 1-fetoprotein
Can be used as a tumor marker is because it is elevated in serum from patients with liver cancer and germ cell tumors
What is elevated in nephrotic syndrome because it's large size prevents it being lost into the urine
Alpha 2-macroglobulin
What causes an elevation of CSF protein
Blood brain barrier damage, multiple sclerosis, bacterial meningitis
At least 90% of plasma copper is attached to
Ceruloplasmin
Primary structure
Determined by the type and number of amino acids and their sequence
Secondary structure
1- dimensional shape the strand of an amino acid takes
tertiary structure
3- dimensional structure that forms as a result of hydrophobic interactions
Quarternanry structure
Formed when two or more chains attract to form aggregaes
Amphoteric
Denotes amino acids have 2 ionizable sites
Denaturation
Disruption of bonds holding the protein structure together
Conjugated proteins
Contains permanently associated non amino group acids
Simple protein
Composed only of amino acids
Troponin
Serum protein used to detect and evaluate acute myocardial infractions
The end product of protein catabolism
Urea
Albumin is classified as a
Transport protein
Maintenance of the colloidal osmotic pressure of plasma is collective function of
Total protein
C reactive protein
It's one of the first acute phased reactants to rise in response of inflammation. Elevated levels can have a casual relationship with cardiovascular disease. Named because of its reaction with C polysaccharide of cell walls of pneumococci
What plasma proteins are senthesized in the liver
Albumin, haptoglobin, fibrinogen, ceruloplasmin
What is a common test used to find serum total protein
Biuret reaction
Serum contains the same proteins as plasma except for
fibrinogen
Albumin
Is responsible for nearly 80% of colloid osmotic pressure of intravascular fluid. Bonds to various substances in the blood and may serve to transport them. Levels that are decreased are more clinically significant than those that are decreased
What test is used in order to detect diabetic nephropathy early in the course of the disease
Microalbumin
Which protein can be found in urine but not serum
Microalbumin
Those plasma proteins that increase in response to acute inflammation are
Acute phase reactants
What is most commonly used to diagnose Wilson's disease
Decreased ceruloplasmin serum levels
Which protein is most commonly assessed in the coagulation department of the clinical lab
Fibrinogen
What complex proteins have a prosthetic group composed of carbohydrates
Glycoproteins and mucoprotein
Proteins that contain amino acids that are linked to each other by peptide bonds formed when
The carboxyl group of one amino acid joins the amino group of another
The pH at which an amino acid is neutral is called the
Isoelectric pount
What is not a necessary amino acid in the human diet
Collagen
What protein functions as an iron transport protein
Transferrin
Ig increased in allergic reactions
IgE
What Ig is synthesized by the mother but present in new born serum
IgG
What Ig is found in saliva, tears, sweat, colostrum, and nasal secretions
IgA
What Ig is the first to be developed by a fetus
IgM
What are some causes of hypoproteinemia
Increased protein loss, malabsorption disorders, extensive burns, blood loss due to trauma
About 16% of protein mass is composed of
Nitrogen which differentiates proteins from lipids
What beta 1 globulin functions as a transport protein that binds free heme after hemoglobin has been catabolized
Haptoglobin
Simple proteins are
Only composed of amino acids
Describe protein metabolism and nitrogen balance
Nitrogen has no designated storage deposits in the human body. Most proteins in our body are constantly being synthesized and degraded. Hepatocytes convert ammonia to urea which is then excreted in urine.
Alpha 1 antitrypsin
It's most important function is the inhibition of the protease neutrophil elastase which can destroy alveoli and lead to emphysema
Renal failure, inflammation, and malignancies cause an elevated plasma level of
Beta 2 microglobulin
Normal total serum protein range for an adult
6.5-8.3 g/dl
Protein electrophoresis
It separates proteins on the bases of their charge densities, all major serum proteins carry a net negative charge at a pH of 8.6. Prealbumin and albumin travel farthest to the anode in a SPEP. Five major bands are; gamma, beta, alpha 1, alpha 2, albumin
maple syrup urine disease
Characteristic is a burnt sugar odor
Aminoacidopathies
They are disorders involving abnormal activity of a specific enzyme in a certain metabolic pathway, abnormal membrane transport system for amino acids, and there are over 100 diseases
General characteristics of proteins
Typical protein contains 200-300 amino acids, a proteins nitrogen content is what sets it apart from pure carbs and lipids. If there is a charge at the protein surface it's hydrophilic. The amino acids of a protein are joined together by peptide bonds
General functions of a protein
make up antibodies, cell structure and extracellular matrix, transport of body fluids
PKU
Abnormally high level of the amino acid phenylalanine accumulates due to the almost total absence of activity of the enzyme PAH
Causes of hyperproteinemia
Include vomiting, diarrhea, and excessive sweating
Myoglobin
It's heme protein found in cardiac and skeletal muscle.it can reversibly bond to oxygen like hemoglobin. After AMI increases within 2-3 hours of onset peaks at 8-12
Determining albumin
Dye binding procedures
Amyloid
May be deposited in tissues potentially causing organ failure
PKU
Retarded metal development occurs, dietary treatment indefinitely, enforced screening programs, common screening procedure is Guthrie bacterial inhibition assay
Homocystinuria
Patients begin to suffer from thrombosis beginning in late hildhoos which results from the toxicity of homocysteine to the vascular endothelium
essential amino acids
Arginine, histidine, isoleucine/leucine/valine, lysine, methionine, phenylalanine, threonine, and tryptophan
Troponin
Ordered along with CK, CK-MB, myoglobin. Gold standard for diagnosing acute coronary syndrome in which blood supply to the heart muscle is suddenly impeaded
BNP B type natriuretic peptides are
Produced as 134 amino acid prepropeptide cleaved into proBNP108 (molecule found in myocytes) BNP is found greatest in the left ventricular myocardium. Important marker for congestive heart failure.
Ammonia sample requirements
Venous blood should be obtained without trauma and be placed in wet ice immediately. Heparin or EDTA . Centrifuged at 0-4C within 20 minutes of collection and plasma/serum removed. No smoking before collection.
MRDR variables
Serum BUN, serum albumin, ethnicity
MRDR-IDMS
Age, sex
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