Clinical Chemistry - Glucose

1) complex sugar composed of many single sugars 2) a chemical reaction measured by a color change 3) simple sugars composed of a single sugar 4) chemical reaction catalzed by enzymes 5) simple sugar composed of two sugars ANSWERS: A. Monosaccharide B. Disaccharide C. Polysaccharide D. Colorimetric E. Enzymatic

1. C 2. D 3. A 4. E 5. B

The most specific method for the measurement of glucose utilizes: A. Hexokinase B. Glucose oxidase C. Glucose dehydrogenase D. O-toluidine

A. Hexokinase

Blood glucose levels in the body are decreased by the hormone: A. insulin B. growth hormone C. thyroxine D. epinephrine

A. Insulin

The metal ion necessary for the Hexokinase enzyme to function is: A. Mg B. Cl C. PO4 D. Ca

A. Mg

An example of a disaccharide is: A. sucrose B. fructose C. galactose D. glucose

A. Sucrose

The form of glucose that is sotred in the muscle and liver is: A. glycogen B. maltose C. lactose D. starch

A. glycogen

The general name for a 6 carbon sugar is: A. hexose B. ribose C. ketose D. pentose

A. hexose

In an oral GTT, the cause of a falsely elevated TBS result could be due to: A. incompletely fasting patient B. glycolysis in patient sample C. short sampling patient sample D. reading at wrong wavelength

A. incompletely fasting patient

The O-Toluidine method for measurement of glucose is a(n): A. oxidation - reduction reaction B. copper reduction reaction C. double enzymatic reaction D. UV - kinetic reaction

A. oxidation-reduction reaction

The Hexokinase method for glucose measurement is based on: A. reduction of coenzyme NAD at 340 nm B. development of a rose-pink chromagen C. formation of hydrogen peroxide substrate D. reduction of copper (II) to copper (I)

A. reduction of coenzyme NAD @ 340nm

In the UV Kinetic methods, the change in absorbance is measured at: A. 540 nm B. 340 nm C. 650 nm D. 400 nm

B. 340nm

The normal range for serum glucose is: A. 60 - 150 mg/dl B. 70 - 110 mg/dl C. 75 - 135 mg/dl D. 80 - 120 mg/dl

B. 70-110 mg/dL

Excess glucose is converted to glycogen in the Liver by: a. Gluconeogenesis b. Glycogenesis c. Glycolysis d. Glycogenolysis

B. Glycogenesis

The disaccharide that is composed of one glucose + one galactose is: a. Maltose b. Lactose c. Sucrose d. Fructose

B. Lactose

The chemical used in grey stoppered tubes to help preserve the integrity of blood glucose concentration is: A. Na citrate B. Na fluoride C. Na oxalate D. Li heparin

B. Na Fluoride

The reducing properties of glucose are due to the functional group: A. carboxyl group B. carbonyl group C. amino group D. hydroxyl group

B. carbonyl group

A one hour OGTT performed on a pregnant patient is called a __________ tolerance test: A. congenital B. gestational C. dependent D. independent

B. gestational

For 3 days prior to a glucose tolerance test, it is recommended that the patient: A. restrict daily carbohydrate intake B. ingest 150 g of carbohdrates daily C. restrict daily physical activity D. stop taking non-prescription medications

B. ingest 150 grams of carbohydrates daily

A carbohydrate that on hydrolysis yields many simple sugars is a(n): A. a monosaccharide B. a polysaccharide C. a disaccharide D. an aldopentose

B. polysaccharide

In a normal OGTT, the blood sugar rises: A. up to 2X normal within 1 hour; returns to normal in 2 hrs B. up to threshold value within 1 hour; returns to normal in 2 hrs C. up to 300 mg/dl in one hour and slowly returns to normal in 8 hrs D. rises steadily for 2 hours, then slowly returns to normal in 4 hrs

B. up to threshold value within 1 hr; return to normal in 2 hrs

A 2 hr. post-prandial sugar is a blood specimen that is collected: A. drawn 5 hours after ingestion of glucose B. drawn on a 12 hour fasting patient C. collected 2 hours after eating a meal D. for glucose drawn at any time of day

C. 2 hrs after eating a meal

The lower level Critical value for blood glucose is: A. 75 mg/dl B. 60 mg/dl C. 35 mg/dl D. 15 mg/dl

C. 35 mg/ dL

The concentration of glucose given to an adult patient in the oral GGT is: A. 20 - 25 g B. 45 - 50 g C. 75 - 100 g D. 100 - 125 g

C. 75 - 100 grams

In digestion, the enzymes that catalyze the breakdown of starch to glucose is: A. lipase B. hexokinase C. amylase D. trpysin

C. Amylase

The enzyme or enzymes that require NAD+ as a coenzyme include: A. Glucose oxidase B. Peroxidase C. G-6-PD D. Hexokinase

C. G-6-PD

The best plasma specimen for glucose analysis is usually obtained from a tube containing sodium fluoride (NaF) because: a. Sodium Fluoride is a good anticoagulant for glucose analysis b. Sodium Fluoride is a good preservative for preventing hemolysis c. Sodium Fluoride inhibits glycolysis d. all of the above

C. NaF is a good preservative for preventing glycolysis

The purpose of a 5 hour glucose tolerance test is in diagnosis of: A. malabsorption of carbohydrates B. hereditary disorders of metabolism C. classic cases of hypoglycemia D. insulin dependent diabetes mellitus

C. classic cases of hypoglycemia

The principle of the glucose condensation method is: A. glucose + oxygen ---> H2O2 + glucuronic acid B. glucose + CuSO4 ---> Cu2O + glycosylamine C. glucose + o-toludine --> oxidized o-toludine + sugar acids D. glucose + ATP --> glucose-6-phosphate + ADP

C. glucose + O-toluidine ---> oxidized O-toluidine + sugar acids

The laboratory test that provides the physician with information about glucose intake over a 2-3 month period is: A. fructosamine B. glucose tolerance C. glycosylated Hgb D. fasting blood sugar

C. glycosylated Hgb (also called Hgb A1C)

In the glucose oxidase method for measurement of blood sugar, the enzyme peroxidase oxidizes: A. glucose to glucuronic acid B. glucose to pyruvic acid C. hydrogen peroxide to water D. glucose to phosphogluconate

C. hydrogen peroxide to water

During digestion of carbohydrates, all sugars are absorbed into portal circulation as: A. chylomicrons B. polysaccharides C. monosaccharides D. free fatty acids

C. monosaccharides

In the UV kinetic method for measurement of glucose, the function of the Hexokinase enzyme is to: A. remove H+ from glucose B. remove H+ from NADH C. transfer PO4 from ATP D. break C = O bond

C. transfer PO4 from ATP

In digestion of carbohydrates, the function of the liver is: A. hydrolysis of starches & carbohydrates B. convert galactose & fructose to glucose C. convert excess glucose to glycogen D. both B & C are correct

D. 1) convert galactose & fructose to glucose 2) convert excess glucose to glycogen

The serum glucose concentration of a nromal patient undergoing a 2 hr OGTT should return to the baseline (fasting level) after a minimum or: A. 30 mins B. 60 mins C. 90 mins D. 120 mins

D. 120 minutes

When the blood sugar is below 60 mg/dL, the condition is referred to as: A. hyperglycemia B. diabetic acidosis C. hyperchlorhydria D. hypoglycemia

D. Hypoglycemia

In the condensation method for measurement of glucose, the substance that reacts with glucose forming a blue-green color is: A. copper sulfate B. copper tartrat C. Na hydroxide D. O-toludine

D. O-Toluidine

A blood specimen for a fasting blood sugar (FBS) must be drawn: A. two hours after a meal B. 5 hrs after drinking glucose C. anytime of day or night D. after 8 - 12 hour fast

D. after 8-12 hour fast

An example of a congenital disorder of carbohydrate metabolism is: A. Sickle cell anemia B. Beta thalassemia C. Tay-Sach's disease D. Galactosemia

D. galactosemia

Diabetes Mellitus is associated with these symptoms: A. increased thirst B. weight loss C. elevated blood sugar D. all of these

D. increased thirst, weight loss, and elevated sugar

The form of Diabetes that manifests later in life and is associated with obesity, physical inactivity, and glycosuria, is: A. congenital diabetes B. gestational diabetes C. insulin dependent D. non-insulin dependent

D. non-insulin dependent

In an oral lactose tolerance test, the patient is normal if the fasting glucose: A. rises steadily for 2 hrs, then returns to normal B. rises to twice normal @ 1 hour, but normal in 2 hrs C. level fails to rise more than 20 mg/dl above fasting D. riases 25 mg/dl or more above the fasting level

D. raises 25 mg/dL or more above fasting level

A disaccharide molecule forms between 2 monosaccharides as a result of loss of one: a. oxygen molecule b. hydrogen molecule c. nitrogen molecule d. water molecule

D. water molecule

Which of the following falsely decreases the glucose level in the sample? a. hemolysis b. ascorbic acid c. glycolysis d. tetracycline e. all of the above

E. all of the above

A decrease in the glucose level of hemolyzed specimens is caused by the catalysis of glucose by the catalytic enzymes released from red blood cells: True False

True

The following reaction for measurement of glucose is catalyzed by: ATP + glucose ---> glucose-6-PO4 + ADP A. glucose oxidase B. hexokinase C. hexose isomerase D. Phosphoperoxidase

b. Hexokinase

INTERPRETATION: Glucose tolerance tests (GTT) were administered to a patient. The following values were obtained. Collection time OGTT results IV GTT results Fasting 80 80 30 min 90 145 60 min 87 130 120 min 85 80 180 min 80 75 The most likely explanation for the difference in results between the oral GTT and the IV GTT is: a. values obtained were done by 2 different methods b. results of the IV test are not reasonable or reliable c. the orally administered glucose was poorly absorbed d. specimens were not collected properly

c. the orally administered glucose was poorly absorbed

Symptoms of Type I or Insulin dependent diabetes mellitus include: A. fatigue B. polyuria C. glucosuria D. all of these

d. fatigue, polyuria, and glycosuria