Term
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Definition
Proteins are catabolized into amino acids via enzymatic proteolysis. The amino acids undergo transamination and oxidative deamination to be converted into ammonia, which enters the "urea cycle". Urea is synthesized from the "urea cycle" |
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Term
What are some of the modes of urea excretion? |
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Definition
90% of urea is excreted through its kidneys
There are some losses through the gastrointestinal tract and skin |
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Term
Disease states and disorders associated with urea (BUN) measurement |
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Definition
Kidney disease shows accumulation of urea in blood
Uremic (azotemic) state: increase in [blood urea] |
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Term
Discuss the methodologies used for urea nitrogen (BUN) measurement (pages 369 - 370) |
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Definition
Fearon Reaction (chemical method): molecules of diacetyl condense with those of urea to form the chromogen diazine, which absorbs strongly at 540 nm.
Enzymatic Methods: based on preliminary hydrolysis of urea with urease to generate ammonia; use spectrophotometry (Berthelot reaction and enzymatic assays) |
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Term
Chemical structure of creatinine |
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Definition
cyclic anhydride of creatine |
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Term
Synthesis of Creatinine (see p. 365) |
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Definition
final product of decomposition of phosphocreatine as well as the spontaneous dehydration of creatine |
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Term
Mode of creatinine excretion |
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Definition
Excreted in the urine.
(note: although it is present in all body fluids and secretions and is freely filtered by the glomerulus) |
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Term
Clinical significance of creatinine |
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Definition
marker of glomerular filtration rate
implicated in diabetes, hypertension, and congestive heart failure |
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Term
principle of Jaffe reaction |
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Definition
creatinine reacts with picrate ion in an alkaline medium to yield an orange-red complex |
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Term
Analytical problem of Jaffe raction |
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Definition
lack of specificity for creatinine
many compounds have been reported to produce a Jaffe-like chromagen |
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Term
The greatest success in common usage and specificity for the Jaffe reaction (chemical method) |
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Definition
use of a kinetic measurement approach in combination with careful choice of reactant concentrations |
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Term
Advantages of kinetic assays for Jaffe Reaction |
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Definition
more specific, faster, and the analysis is automated |
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Term
Maximum concentration of picrate that can be used in a Jaffe reaction. Also name the concentration range employed in most methods. |
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Definition
30 mmol/L maximum
3 - 16 mmol/L |
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Term
What can high concentrations of hydroxide cause in the Jaffe reaction? |
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Definition
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Term
Absorbance maximum of the Jaffe reaction |
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Definition
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Term
chemical sructure of uric acid |
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Definition
nitrogenous compound (2,6,8-trihydroxypurine) |
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Term
Synthesis of uric acid (p. 370 - 371) |
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Definition
major product of catabolism of the purine nucleosides adenosine and guanine.
Both endogenous and exogenous nucleic acids are degraded/catabolized into uric acid. |
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Term
Mode of excretion of uric acid |
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Definition
Highly present in the urine and can be found in serum
Did you know that it can be crystallized in the serum and deposited in the joints? |
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Term
Clinical significance of uric acid |
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Definition
there are more than 20 disorders of purine metabolism that cause hyperuricemia and hypouricemia
suspicious symptoms: kidney failure/stones in children or young adult, unexplained neurological problems in infant - adolescent, gout in man/woman <30 years old |
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Term
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Definition
monosodium urate precipitates from supersaturated body fluids |
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Term
What are the three methods to measure uric acid? |
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Definition
Phosphotungstic Acid Method, Uricase Method, and HPLC Method |
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Term
Drawback of the Phosphotungstic Acid (PTA) Method |
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Definition
sunject to many interferences |
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Term
Advantage of the Uricase Methods |
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Definition
more specific than the PTA methods |
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Term
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Definition
aldehyde or ketone derivatives of polyhydroxy alcohols composed of carbon, hydrogen, and oxygen in a ratio of 1:2:1 |
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Term
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Definition
a simple sugar that consists of a single polyhydroxy aldehyde or ketone unit and is unable to hydrolyzed to a simple form |
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Term
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Definition
two monosaccharides joined covalently by an O-glycosidic bond, with the loss of a water molecule. |
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Term
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Definition
the linkage of multiple monosaccharide units |
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Term
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Definition
chemical bond between monosaccharides? |
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Term
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Definition
monosaccharide (a simple sugar) that contains only one aldehyde (-CH=O) group per molecule |
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Term
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Definition
a monosaccharide containing one ketone group per molecule. |
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Term
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Definition
any of the class of simple sugars whose molecules contain six carbon atoms, such as glucose and fructose. |
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Term
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Definition
each of two or more compounds with the same formula but a different arrangement of atoms in the molecule and different properties |
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Term
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Definition
compounds that are identical in composition and differ only in spatial configuration |
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Term
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Definition
formation of glycogen from glucose |
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Term
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Definition
the breakdown of glycogen to glucose |
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Term
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Definition
production of glucose from noncarbohydrate sources |
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Term
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Definition
the breakdown of glucose by enzymes, releasing energy and pyruvic acid |
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Term
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Definition
transformation of glucose to pyruvate when limited amounts of oxygen |
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Term
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Definition
acetyl ester of coenzyme A, involved as an acetylating agent in many biochemical processes |
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Term
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Definition
an extensively branched polysaccharide containing many glucose residues and found particularly in muscle and liver cells for glucose storage |
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Term
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Definition
the metabolic formation of fat/lipids |
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Term
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Definition
the breakdown of fats and other lipids by hydrolysis to release fatty acids |
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Term
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Definition
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Term
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Definition
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Term
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Definition
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Term
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Definition
a mixture of amyloses and amylopectins |
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Term
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Definition
similar to amylopectins, but branching is more extensive and is evident every 8 to 12 glucose residues |
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Term
Clinical Significance of Glycogen |
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Definition
Glycogen Storage Disease (p. 382) |
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Term
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Definition
proteins that have carbohydrate groups attached to the polypeptide chain |
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Term
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Definition
protein bonded to glycosaminoglycan groups |
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Term
Ingestion and Absorption of Carbohydrate |
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Definition
Once eaten, amylase (salivary) breaks down starch into glucose and disaccharides into monosaccharides
Carbohydrates are absorbed in the intestines and liver |
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Term
main physiological functions of glucose |
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Definition
structureal components in RNA and DNA
source of energy |
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Term
pentose phosphate pathway |
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Definition
a biochemical pathway parallel to glycolysis that generates NADPH and pentoses (5-carbon sugars) |
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Term
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Definition
metabolic pathway that converts glucose to pyruvate |
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Term
Insulin effect in regulating blood glucose level |
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Definition
It decreases blood glucose level via glycogenesis, glucose uptake (entering the cell), and lipogenesis |
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Term
Effects of glucagon in reguling blood glucose levels |
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Definition
increases blood glucose via glycogenolysis and gluconeogenesis |
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Term
Maintenance of blood glucose levels in "fasting state" |
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Definition
1) Decrease in blood [glucose] stimulate α-cells of pancreas to secrete glucagon
2) Glucagon causes lipolysis, glycogenolysis, and gluconeogenesis to occur, yielding normal blood [glucose] |
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Term
The maintenance of glucose levels in the "fed state" |
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Definition
1) An increase in blood [glucose] cause the β-cells of the pancreas to release insulin
2) Insulin causes lipogenesis, glucose uptake, and glycogenesis to occur |
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Term
Growth hormone effect on blood glucose levels |
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Definition
The growth hormone stimulates gluconeogenesis, enhances lipolysis, and antagonizes insulin-stimulated glucose uptake |
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Term
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Definition
Abrupt onset of symptoms: polyuria, polydipsia, and rapid weight loss
Insulinopenia (deficiency of insulin) due to loss of pancreatic β cells; autoantibody may be involved
Peak incidence occurs in childhood and adolescence
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Term
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Definition
Minimal symptoms, not prone to ketosis, and not dependent on insulin
[Insulin] may be normal, decreased, or increased; insulin action may be impaired
Obesity is commonly associated
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Term
Gestational Diabetes Mellitus |
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Definition
Carbohydrate intolerance of variable severity with onset or first recognition during pregnancy. |
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Term
Risks for Gestational Diabetes Mellitus |
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Definition
1) women who have marked hyperglycemia during or soon after pregnancy
2) women who are obese
3) women whose GDM was diagnosed before 24 weeks' gestation |
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Term
Principle of glucose oxidase method |
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Definition
Glucose + H2O + O2 →(glucose oxidase)→ Glucaronic Acid + H2O2
H2O2 + Reducing Dye (color #1) →(peroxidase)→ Oxidized Dye + H2O
The more oxidied dye there is, the more H2O2 produced, thus, the more glucose initially present |
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Term
Interferences of the Glucose Oxidase method |
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Definition
uric acid, ascorbic acid, and bilirubin |
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Term
Principle of Hexokinase Method |
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Definition
Glucose is phosphorylated in presence of hexokinase and forms Glucose-6-phosphate. Glucose-6-phosphate is oxidized by G6PD to another product in the presence of NADP+ or NAD+
The amount of reduced NADP or NADH produced is directly proportional to the amount of glucose in sample (340 nm ABS) |
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Term
Required Sample Types for Hexokinase Method |
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Definition
plasma or serum.
NaF, with an anticoagulant may be used
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Term
Sources of Interferences for Hexokinase Methods |
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Definition
Hemolyzed specimens containing more than 0.5g of Hgb/dL
drugs, bilirubin, and lipemia |
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Term
Specimens for Glucose Oxidase Method |
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Definition
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Term
Method used in lab to measure Glycohemoglobin A1C |
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Definition
Helena GLYCO-Tek Affinity Column Method |
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Term
Principle of the Helena GLYCO-Tek Affinity Column Method |
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Definition
The dihydroxyboryl group in the cellulose reesin has an affinity to cis-diol groups on simple sugars, thus allowing separation of glycated hemoglobins from non-glycated.
Elution with a basic developer removes non-glycated Hb. The glycated forms are eluted using sorbitol buffer. Then spectrophotometry |
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Term
Specimen for Glycohemoglobin methods |
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Definition
Fresh, whole blood containing EDTA, heparin, or citrate. Packed cells are the specimen of choice. |
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Term
Interfering substances for the Glycohemoglobin method |
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Definition
hemolyzed, lipemic, and icteric specimens |
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Term
Patient Preparation for Glucose Tolerance Test |
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Definition
1) Patient has 3 days of unrestricted diet
2) Collect blood after patient has fasted for at least 8 hrs
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Term
Procedure for Glucose Tolerance Test |
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Definition
1) Collect patient sample from 8-hour fast
2) Give 75g of glucose
3) Collect blood every half hour (up to 2 hours)
4) Patient is considered diabetic if the 2-hour test tube (and another test tube) is >200 mg/dL
Normally, 7% of blood glucose is lost every hour (cellular glycolysis) |
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Term
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Definition
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Term
Criteria for diagnosing Diabetes Mellitus in fasting plasma glucose |
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Definition
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Term
Criteria for diagnosing Diabetes Mellitus in 2-hour plasma glucose |
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Definition
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Term
The two families of protein that modulate glucose transport into the cells |
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Definition
1) sodium-dependent glucose transporter (promote the uptake of glucose and galactose from the lumen of the small bowel and their reabsorption from urine in the kidney)
2) facilitative glucose transporter (located on the surface of all cells) |
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Term
Methods used to measure ketones in body fluids |
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Definition
1) Acetest
2) Ketostix
3) Determination of β-hydroxybutyrate |
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Term
Most common analytical method of ketones |
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Definition
sodium nitroferricyanide + ketones yield a purple complex |
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Term
Qualitative Method to measure Glucose in Urine |
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Definition
Benedict's Test
Aldose + Cu(citrate)22- (blue) → carboxylate anion and Cu2O (brick red ppt)
If the color of the solution changes, glucose is present (spectrophotometry?) |
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Term
Quantitative Methods to measure Glucose in Urine |
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Definition
Hexokinase and glucose dehydrogenase procedures are recommended for greatest accuracy |
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Term
Quantitative Method to measure Glucose in CSF |
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Definition
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Term
Three Methods for Determination of Glycated Hemoglobins |
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Definition
1) High-Performance Liquid Chromatography
2) Immunoassay
3) Affinity Chromatography (*done in lab) |
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Term
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Definition
a class of compounds that are soluble in organic solvents but are nearly insoluble in water and that contain nonpolar carbon-hydrogen bonds |
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Term
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Definition
compound that contains fatty acids and no prosthetic groups; simple fatty acids; monomers of complex lipids |
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Term
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Definition
Lipid containing esters, fatty acids, alcohol groups, and other prosthetic groups; a macromolecule composed of simple lipids (e.g. triglycerides) |
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Term
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Definition
an organic compound made up of glycerol and three fatty acid chains. Fat is stored as triglycerides |
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Term
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Definition
a polar amphipathic lipid located on the surface of a lipoprotein; they are also found at the aqueous interface of biological membranes |
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Term
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Definition
any group of yellow-brownish fatty substances occurring in animal and plant tissues composed of phosphoric acid, choline, fatty acids, glycerol, glycolipids, triglycerides, and phospholipids.
major surfactant found in the lung; used along with sphingomyelin to assess fetal lung maturity |
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Term
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Definition
a lipid compound that coats lung cells
substance that occurs widely in brain and nervous tissue, consisting of complex phosphoryl derivatives of sphingosine and choline |
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Term
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Definition
a lipid with a carbohydrate component |
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Term
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Definition
protein that together with a prosthetic group forms a particular biochemical molecule such as a hormone or enzyme
apolipoproteins are the major components of lipoproteins |
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Term
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Definition
spherical particles involved in the transport of lipids with nonpolar neutral lipids (triglycerides and cholesterol esters) in their core and more polar amphipathic lipids (phospholipids and free cholesterol) at their surface |
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Term
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Definition
-
a pancreatic enzyme that catalyzes the breakdown of fats to fatty acids and glycerol or other alcohols
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Term
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Definition
the presence in the blood of an abnormally high concentration of emulsified fat |
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Term
Saturated fatty acids vs. unsaturated types |
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Definition
Saturated fatty acids have no double bond between their carbons
Monounsaturated fatty acids contain one double bond
Polyunsaturated fatty acids contain multiple double bonds |
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Term
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Definition
A microscopically visible particle appearing in the plasma after a fatty meal.
Over 90% of TGL make up chylomicrons |
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Term
VLDL - Very Low Density Lipoprotein |
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Definition
Composition: 50-65% TGL, 15% cholesterol, +proteins
Function: carries endogenous cholesterol and other TGL from liver to tissues |
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Term
LDL = Low Density Lipoprotein |
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Definition
Composition: primarily cholesterol about 50%
Function: primary chosterol transport from liver to tissues; transports most of the TGLs? |
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Term
HDL = High Density Lipoprotein |
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Definition
Composition: AI & AII apolipoprotein and contains cholesterol ester
Function: "cholesterol scavenger"; esterification of cholesterol and transports cholesterol from tissues to liver, where it is converted to bile acids and excreted. |
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Term
Emusification and absorption of dietary lipids |
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Definition
The digestive enzyme, lipase, is water soluble and can only work at the surface of fat globules. Digestion is greatly aided by emulsification, the breaking up of fat globules into much smaller emulsion droplets. Bile salts and phospholipids areamphipathic molecules that are present in the bile. Motility in the small intestine breaks fat globules apart into small droplets that are coated with bile salts and phospholipids, preventing the emulsion droplets from re-associating |
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Term
Physiological Function of Lipids |
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Definition
hormones, energy source, assisting digestion, structural component of cellular membrane |
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