Clinical Chemistry Review 1-110

Chemistry Review 1-110 Which of the four elements in proteins Differentiates this class of substances from carbs and lipids?

Nitrogen

Which of the proteins is soluble in water?

Albumin

How many amino acids joined together to form a chainlike structure?

peptide bonding

Proteins may become denatured when subjected to mechanical agitation, heat, or chemical treatment. What does denaturation of protiens refer to?

Alteration of tertiary structure

Which aminoacidopathy is NOT caused by an enzyme deficiency?

cystinuria

How many immunoglobulin classes are currently recognized?

five

Which reagent is employed in th eserum protein determination?

Biuret

Why should hemolyzed serum not be used for total protein analysis?

Hemolglobin is absored at the wavelength as protein in the reagent

Why is bromcresol purple the prferred indicator for albumin dye binding techniques?

there is less interference form pigment(s).

What is the most anodic protein on electrophoresis at pH 8.6

Albumin

If an electrophoretic pattern shows 30%albumin, 4-10% alpha-globulin, and 45% gammaglobulin,then what condition may exist in the patient?

Monoclonal gammopathy

Glycoportiens and mucoprotiens are usually bound to which substances?

Carbohydrates

All of the following are glycoproteins EXCEPT which one? ceruloplasmin, FSH, fibrinogen or cryoglobulin.

cryoglobulin

Which one of the following applies to cryoglobulins? a)they are temperature sensitiveb)the specimen should clot at room temp.c)the specimen is incubated at 22degrees C for 24hrs.d) only quanititative tests are available

a)they are temperature sensitive proteins

Decreased alpha-fetoprotein values are associated with which condition?

down syndrome

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Chemistry Review 1-110 Which of the following proteins transports iron? ceruloplasmin, hemopexin transferrin or haptoglobin

transferrin

In acute renal failure, which nonprotein nitrogen rises the fastest?

Blood Urea Nitrogen(bun)

By the urease method, urea is enzymatically converted to which end product?

ammonia

Why can untreated urine be usded for the determination of urea by the diacetyl monoxime method?

the method is not measuring ammonia

An elevated creatinine value is most likely to be accompanied by what values?

elevated blood urea nitrogen, 10x creatinine value

What is the classical method for creatinine reaction?

Jaffe

The measurement of creatinine is based on the fomation of a yellow-red color and which reagent?

alkaline picrate

The creatinine clearance test is based on whcih assumption?

creatinine passes into the ultrafiltrate

What is the most common clearance test used to measure the glomerular filtration rate?

creatinine

Which disease state is associated with an elevation of serum uric acid?

gout

Which reagent is employed in the alkaline oxidation of uric acid?

phosphotungstic acid

What does the uricase method for uric acid depend on?

ultraviolet absorption at 290nm before/after treatment with uricase

Which one of the analytes is ued as a prognostic indicator for liver failure?

ammonia

Which disaccharide is composed of two glucose molecules?

maltose

What term is used to describe the process of glycogen degradation?

glycogenolysis

What is the renal threshold for glucose?

140-160 mg/dL

Which hormone is produced by the beta cells o fth islets of Langerhans?

insulin

Which one o fthe following hormones is considered a glucocorticoid?

cortisol

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Chemistry Review 1-110 Which one of the following disease is associated with hypoglycemia? Von Gierke's disease, Hashimoto's disease,Cushing's disease or Gilbert disease

Von Gierke's disease

What is the specimen of choice for glucose dterminations?

fluorinated plasma

What is the most frequently employed automated method for glucose?

coupled enzyme system consisting of glucose oxidcase and peroxidase

Contamination of the glucose reagent with catalase is a problem with which glucose method?

glucose oxidase

What is the hexokinase methodolgy for glucose dtermination based on?

reduced coenzyme read at 340nm

What is the normal fasting blood lucose reference range for adults?

70-120 mg/dL

What does the presence of urinary ketones MOST likely indidcate?

The body is using cabohydrates as the primarty energy source.

Which one of the following tests is used to differentiate between inappropritate exogenous insulin administration and endogendous insulin production?

C-peptide

The "port wine" color of some urine can be attributed to which of the following?

porphyrins

p-dimethylaminobenzaldehyde is a constituent of which reagent?

Ehrlich

Both pophobilinogen and urobilinogen from a red colored compound with Ehrlich's reagent. How can they be differentiated?

urobilinogen is soluble in chloroform

Prehepatic bilirubin has whcih of the following for a protien carrier?

albumin

Direct-reacting bilirubin is alo known as what substance?

bilirubin diglucuronide

An increase in indirect-reacting bilirubin is suggestive of which condition?

hemoglobin breakdown

Bilirubin is converted in the intestine to which of the following substances?

urobilinogen

Which of the following will interfere with the Evelyn Malloy method for bilirubin? hemolysis,mehtanol, caffeine or lipemia

hemolysis

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Chemistry Review 1-110 Which one o fthe following definitions best descrbes an enzyme?

Biological catalyst

Which of the following is true of an isoenzyme?

The electrophoretic property is differnt for each isoenzyme

Why is a metal ion somtimes necessary in an enzymatic reaction?

acts as an activator of the enzyme

The Michaelis-Menten constant in the rate of conversion of substrate to product is determined by what factor?

substrate concentrationand the rate of dissociation of the complex

In a zero-order reaction, there will be no further increase in velocity due to which one of the following?

all enzyme is bound to substrate

What is the reporting unit of measure for enzymes?

IU/L

Which enzyme catalyzes this reation? lactate + NAD -> pyruvate + NADH

lactate dehydrogenase

Which of the following is true of the isoenzyme LD1? It is heat-labile, slowest migrating, most positivly charged isoenzyme or is present in the highest concentration in heart tissue.

It is present in the highest concentration in heart tissue

Which enzyme is most greatly affected by hemolysis?

lactate dehydrogenase

An LD isoenzyme elecgtrophoretic pattern that shows an increase in LD1, LD2 and LD3 is seen in which disease state?

pernicious anemia

Creatine kinase is clinically significant is disease of which organ?

muscle

Creatine kinase is frequenly elevated in acute myocardial infarction and which other disorder?

Duchenne's muscular dystrophy

Which serum enzyme begins to rise 2-4 hours , has peak activity occurring 12-36 hrs and returns to normal 2-4 days after an acute myocardial infarction?

creatine kinase

Aspartate transaminase is elevated in all of the following conditions EXCEPT which one? myocardial infarction, muscular dystrophy, acute pancreatitis or liver disease.

acute pancreatitis

Which enzyme is liver specific? aspartate transaminase, alanine transaminase, alkaline phosphatase or lacate dehydrogenase

alanine transaminase

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Chemistry Review 1-110 Which enzyme is the most sensitive indicator of obstructive jaundice?

alkaline phosphatase

A high alkaline phosphatase level in the presence of other negative liver funcgtion test is indicative of which disorder? bone disorder, viral hepatitis, prostate cancer or ectopic pregnancy

bone disorder

What is the optimum pH for acid phosphatase?

5.0

What is the clinical significance of an elevaed acid phosphatase?

prostatic disease

Which enzyme may be monitored in recovering alcoholics?

gamma-glutamyl transferase

Which enzyme is characteristically elevated in mumps?

amylase

Lipase catalyzes the hydrolysis of which substrate?

triglycerides

What is the substrate for the Chery-Crandall lipase method?

olive oil

In which disease state are the highest levels of aldolase seen?

muscular dystrophy

Because ionized calcium can be changed wigthout affecting the total calcium level, what other parameter(s) must beknown to properly evaluagte calcium?

pH and protein

All of the following regulate calcium levels EXCEPT which one? Vit. D, calcitonin, aldosterone, and parathyroid hormone

aldosterone

Which of the following specimens is acceptalbe for the determination of total calcium? EDTA, Fluorinated plasma, oxalated plasma or heparinized plasma.

heparinized plasma

In the complexometric titration (EDTA) method for calcium, the pH must be adjusted to prevent what occurrence?

interference by MAGNESIUM

The classic Clarke-Collip method for calcium is based on which assumption?

Calcium will be precipitated as an oxalate

What is the purpose of lanthanum in the atomic absorption deterination of calcium?

It will bind phosphate

At a pH of 7.4 most of the phosphorus in the body is in which form?

bone

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Chemistry Review 1-110 Inorganic phosphate can be determined from a colorimetric method involving which reagent?

Molybdate

What is the most abundant iron-containing compound in the body?

ferritin

Why should serum iron be drawn at the same time on consecutive days?

to avoid diurnal variation

Which protein trasports the majority of copper in the bloodstream?

ceruloplasmin

Increased serum copper is seen in which disease?

Wilson's disease

Which analyte is an early indicator of tissue hypoxia?

lactic acid

What is the major extracellular cation?

sodium

Which hormone acts on the distal convoluted tubule to increase sodium reabsorption?

aldosterone

What is the most common method for measuring sodium?

ion-selective electrode

Which is one of the following is the major intracellular cation?

potassium

Valinomycin can enhance the selecgtivily of which ISE electrode?

potassium

All of the following can cause low choloride levels EXCEPT which one? diabetic acidosis,renal failure, prolonged vomiting and dehydration

dehydration

Sweat is an appropieate type of specimen for which electrolyte?

chloride

In the coulometric-amperometric method for chloride, how is the amout of chloride measured?

time needed to reach the titration end point

In the classic Schales-Schales mercurimetric titration) method for chloride, what substance reacts with indicator to form a violet color?

excess Hg++

Most of the carbon dioxide in the blood is present in which form?

bicarbonate ion

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