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Chem 2 Ch.10
Amino Acids and Proteins
Term | Definition |
---|---|
Amino Acids | -building blocks of proteins |
Peptide bond | amino acids joining together |
Aminoacidopathies | class of inherited errors of metabolism in which there is an enzyme defect that inhibits the body's ability to metabolize certain amino acids |
Phenylketonuira | Absence of activity of the enzyme phenylalanine hydroxylase |
Tyrosinemia | -Inborn metabolic disorders -characterized by the excretion of tyrosine and tyrosine catabolites in the urine. -5 different enzymes that are needed to break down tyrosine |
Alkaptonuria | -transmitted as an autosomal recessive gene ( HGD), which causes the lack of the enzyme homogentisate oxidase which is needed in the metabolism of tyrosine and phenylalanine. |
Maple Syrup Urine Disease | -absence or greatly reduced activity of the enzyme branched-chain a-ketoacid decarboxylase -blocks the normal metabolism of the three essential branched-chain amino acids leucine, isolucine and valine. - autosomal recessive genetic inherited disorder. |
Isovaleric Acidemia | -autosomal recessive metabolic disorder from a deficiency of the enzyme isovaleryl-CoA dehydrogenase -prevents normal metabolism of the branched-chain amino acid leucine |
Homocystinuria | lack of the enzyme cystathionine-B synthetase -necessary for the metabolism of the amino acid methionine |
Cystinuria | -defect in the amino acid transport system. -inadequate reabsorption of cystine during the filtering process in the kidneys. |
Primary Structure | # and types of amino acids in the sequence |
Secondary Structure | repeating structures stabilized by hydrogen bonds between the amino acids within the protein. ( Pleated sheet or helix) |
Tertiary Structure | overall shape ( fold) |
Quaternary Structure | shape or structure that results from the interaction of more than one protein molecule. (3D) |
Denaturation | loss of its native structure. |
Proteinuria | |
Simple proteins | -contain peptide chains composed of only amino acids. -globular or fibrous |
Conjugated Proteins | -consist of a protein and a nonprotein (prosthetic) group -the prosthetic groups could be lipid, carb, porphyrins & metals -something is JOINED to it |
Globulins | a1-Globulns a2-Globulins Haptoglobulins B-globulins |
Alpha 1-Antitrypsin (AAT) | -glycoprotein mainly synthesized in the lover - most important function inhibition of the protease neutrophil elastase. |
Alpha1- Fetaprotein | -synthesized in the developing embryo and fetus and than by parenchymal cells of the liver. |
Haptoglobin | -a2-glycoprotein synthesized in the hepatocytes. -elevated in many inflammatory diseases |
Transferrin | -glycoprotein -negative acute-phase protein -synthesized in liver |
Siderophilin | transferrin |
Lipoproteins | -complexes of proteins and lipids -transport cholesterol, triglycerides & phospholipids in blood |
B2-Microglobulin | -histocompatibility complex -present in high concentrations on lymphocytes |
Complement | one of the natural defense mechanisms that protects the human body from infections. -synthesized in the liver as single polypeptide chains and circulate blood as nonfunctional precursors. |
Fibrinogen | -one of the largest proteins in blood plasma -synthesized in liver |
C-Reactive Protein | -one of the first acute-phase proteins to rise in response to inflammatory disease. |
Immunoglobulins | -IgG is most abundant -IgG crosses placenta -antibodies produced by the B lymphocyte that confer humoral immunity. |
Myoglobin | -153 amino acids -primary oxygen-carrying protein -muscle protein -toxic to the kidneys and kidneys can be damaged |
Troponin | -"gold standard" |
Brain Natriuretic Peptide | -popular marker for congestive heart failure -found in left ventricle myocardium |
Cystatin C | -low molecular mass protein -120 amino acids -marker for early assessment of changes to the glomerulus filtration rate |
Hypoproteinemia | Low total protein and occurs in any condition where a negative nitrogen balance exists. |
Hyperproteinemia | increase in total plasma proteins, not a disease state but underlying cause of dehydration |
Growth,repair and maintenance of all cells are dependent on? | Amino acids |
Amino acids contains? ( basic structure) | at least one of both amino and carboxylic acid functional groups |
(-NH2) and ( -COOH ) bond to the a-carbon with the amino group of one amino acid linking with the carboxyl group | peptide bond |
catalyzes the conversion of phenylalanine to tyrosine | Phenylalanine hydroxylase |
Type 1 tyrosinemia | -most severe 1 in 100,000 births -caused by low levels of the enzyme fumarylacetoacetate hydrolase |
Type 2 tyrosinemia | -caused by a deficiency of the enzyme tyrosine aminotransferase |
Type 3 tyrosinemia | -rare disorder -caused by a deficiency of the enzyme 4-hydroxyphenylpyruvate dioxygenase. |
Urine turns brownish-black when mixes with air ( aminocidopathy) | Alkaptonuria |
sweaty feet odor | Isovaleric Acidemia |
Cause of a1-Antitrypsin | Mutations in the SERPINA1 gene |
Protein used to evaluate the rheumatic diseases and increased in burns and nephrotic syndrome | Haptoglobin |
Functions of transferrin | transport of iron and the prevention of loss of iron through the kidney |
low transferrin levels | -impaired hemoglobin production and lead to anemia. -due to poor production of transferrin as seen in liver disease or malnutrition or excessive loss of transferrin through the kidneys into the urine. |
increased transferrin levels | iron deficient anemia |
low prealbumin levels | hepatic damage, acute phase inflammatory response and tissue necrosis. -poor nutrition |
increased prealbumin levels | patients receiving steroids, in alcoholism and in chronic renal failure. |
low albumin levels | malnutrition, liver disease, hypothyroidism, dilution by excess, acute disease states, redistribution |
high albumin levels | seen ONLY with dehydration or after excessive albumin infusion |
decreased levels of ceruloplasmin | wilsons disease |
increases levels of ceruloplasmin | inflammation, severe infection & tissue damage |
elevated serum levels of B2-Microglobulin | impaired clearance by the kidney or overproduction of the protein that occurs in inflammatory diseases. |
increased complement | inflammatory states |
decreased complement | malnutrition and hemolytic anemia. |
most abundant complement protein in human serum | C3 |
decreased levels of C3 | autoimmune disease, neonatal respiratory distress syndrome, bacteremia, tissue injury and chronic hepatitis. |
increased fibrinogen levels | inflammatory, pregnancy and use of oral contraceptives |
decreased fibrinogen | reflect extensive coagulation |
increased C-Reactive protein | acute rheumatic fever, bacterial infections, myocardial infarctions, rheumatoid arthritis, carcinomatosis, gout and viral infections |
% of protein composition in immunoglobulins | 82%-96% |
% of carbohydrate composition in immunoglobulins | 4%-18% |
increased IgG | liver disease, infections, IgG myeloma, parasitic disease and many rheumatic diseases |
decreased IgG | acquired immunodeficiency, protein-losing states and non-IgG myeloma |
Increased IgA | liver disease, infections and autoimmune diseases |
decreased IgA | depressed protein synthesis and immunodeficiency |
Increased IgM | toxoplasmosis, primary biiary cirrhosis, cytomegalovirus, rubella, herpes, syphilis and various bacterial and fungal diseases. |
decreased IgM | protein-losing conditions and hereditary immunodeficiency |
Increased IgD | infections, liver disease and connective tissue disorders |
Increased IgE | infectious diseases, asthma, hay fever & IgE myeloma |
increased myoglobin levels | progressive muscular dystrophy & crushing injury in which skeletal muscle is damaged. & renal failure |
increased troponin levels | heart injury is present or that the injury took place more than 24 hours in the past. |
most common test methods for testing proteins | Biuret and Die Binding |
what test used copper ions that caused a deep blue color during total protein analysis | Biuret |
Diseases associated with alterations in cerebrospinal fluid proteins | Bacterial, viral and fungal meningitis; traumatic tap; multiple sclerosis; obstruction; neoplasm; disk herniation & cerebral infarcation |
a1-Antitrypsin Deficiency on elecrophoresis | normal albumin, decrease a1 fraction |
Monoclonal Increase on elecrophoresis | Increased gamma globulin |
Nephrotic Syndrome on electrophoresis | Decreased Albumin, Increased a2 and Beta globulins |
Inflammation on electrophoresis | Increased a1, a2 and beta globulins |
Cirrhosis on electrophoresis | Beta & Gamma Bridge |
Order of fractions on electrophoresis | Albumin, a1, a2, beta than gamma |
Reference range for Total Protein | 65-83 g/L |
Reference range for Albumin | 35-55 g/L |