Enzymes

The normal De Ritis ratio (AST/ALT) should be:

Equal or < 1

Which type of Kinetic reactions are reactions in which the enzyme is in excess and the substrate concentration is the limiting factor?

First order

When measuring enzyme activity, if the instrument is operating 5 degree Celsius lower than the temperature prescribed for the method, how will the results be affected?

Lower than usual

What are the two polypeptide chains that comprise the LD molecule?

M and H

Isoenzymes of CK includes all of the following EXCEPT:

MBM

An important metallic activator of ALP and CK is:

Magnesium

Increases in the MB fraction of CK is associated with:

Myocardial infarction

Lipase is predominately produced in what organ/tissue?

Pancrease

After experiencing extreme jaundice, abdominal pain, and vomiting from extensive hepatocelluar damge, a patient's hepatic function panel is analyzed in the laboratory. The result of the ALT is too high for the instrument to read. Since the instrument does not perform automatic dilutions for ALT, the lab performs a dilution using 100 microliters of patient sample to 400 microliters of diluent. The result now reads 369 U/L. How should this be reported out?

1845 U/L

The recommeneded storage temp for the preservation of activity for MOST enzyme is:

4 degree Celsius

The De Ritis ratio is the calculation of AST/ALT and is used for evaluating liver disease. What should the ratio be when ethanol-related liver disease is expected?

>2.0

Which of the following blood test is used to evaluate liver function?

ALP

Which of the following analytes would be increased due to delay in centrifugation?

AST

A hepatic function panel A consists of which of the following tests?

AST, ALT, ALP, Total protein, Albumin, Totla bili, Direct Bili

Which of the following blood tests is used in the determination of prostate cancer?

Acid phosphatase

Which of the following blood tests is used in the evaluation of hepatic disease?

Alanine aminotransferase (ALT or SGPT)

The ED has collected blood test tubes for potassium, albumun, plasma hemoglobin, and acid phosphatase. Which of these test results will NOT be negatively affected if the blood tube is sent by the hospital's pneumatic tube system?

Albumin

A CMP consists of which group of tests?

Albumin Glucose BUN Creatinine Sodium K Cl CO2 AST ALT ALP TP TBILI Ca

Which clinical situation below is GGT elevation most often associated with?

Alcohol consumption

Which analyte should be increased in the presence of muscular dystrophy?

Aldolase

Which of the following enzymes is associated with conditions affecting skeletal muscles?

Aldolase

All of the following lab test are used to determine kidney function, EXCEPT?

Amylase

Which analyte should be increased in the presence of pancreatitis ?

Amylase

Which of the following blood tests is used to determine acute pancreatitis?

Amylase

All of the statements below regarding amylase and lipase in pancreatitis are TRUE EXCEPT:

Amylase and lipase are as predictive in chronic as in acute pancreatitis

That portion of an enzyme which is separated from its cofactor is called a(n)

Apoenzyme

Serum ALP activity is derived from all of the following EXCEPT:

BRAIN

Given the following data, What is the most likely disease state? Total bili= 4.0 (0.5-1.5) Direct bili= 3.0 (0.2-0.5) AST=75 (2-25) ALT=118 (2-23) LD=220 (<40) ALP=841 (28-68) GGT=150 (21-40U)

Biliary duct obstruction

Following a myocardial infarction, which of the following enzymes will be the first to become elevated:

CK

Which of the statements below regarding the diagnosis of pancreatitis is CORRECT?

Diagnosis sensitivity for acute pancreatitis is increased by assaying both amylase and lipase

Elevation of serum creatinine kinase may be associated with:

Duschenne muscular dystrophy or cerebrovascular (stroke) or vigrous exercise

The properties of enzymes are CORRECTLY described by which of the following statements?

Enzy,es are proteins catalyst of biological origin

Which of the following enzymes is the most sensitive indicator of long term liver damage associated with alcohol ingestion:

GGT

Which of the following is a liver enzyme that is instrumental in allowing glucose to enter the blood stream?

Glucose 6 phosphatase

The Lactate dehydrogenase molecule is made of a combination of polypeptides that can be seperated into isoenzymes that help determine the location of an elevated LD. LD 3 is found primarily in the lung, lymphocytes, spleen, and pancreas but but what polypeptides make up LD3

HHMM

An electrophoretic separation of lactate dehydrogenase isoenzyme that demonstrates elevation in LD-1 greater than LD-2 could be indicative of:

Hemolysis

What role does lipase play in the body?

Hydrolyzes fat esters to produce alcohol and fatty acids

High levels of lipoprotein- associated phospholipase A2 (Lp-PLA 2) are associated with:

Increased cardiovascular risk

A patient presents with an elevation of unconjugated bilirubin, normal serum ALP, normal liver enzymes, and no bilirubin in the urine. This combination would suggest:

Increased rate of hemolysis

The results which would be MOST consistent with macro-amylasemia are?

Increased serum amylase and normal to low urine amylase values

What is the function of LD in the body?

Interconversion of lactate and pyruvate

Which one of the following is a TRUE statement concerning ALP?

It is increased in obstructive jaundice

Isoenzymes of ALP occurs in

Kidney, brain, intestines, liver

According to the Michaelis-Menton Kinetics theory, When a reaction is performed in zero-order kinetics:

The substrate concentration is in excess and the reaction rate is dependent on the enzyme concentration

Which of the following statements is true regarding CYP450 enzymes

They are able to make compounds more water-soluble and therefore enhance excretion

What nfunction in the body does GGT have?

Transfer of gamma-glutamyl peptides amino acids, water, and other peptides

Mrs. Jones, a diabetic, is admitted to the hospital on November 25th. It appears that she has had an acute myocardial infarction (AMI), but did not feel the severe chest pain because of dibetic neuropathy. She has not felt well since November 20th and her physician believes she possibly had an AMI on November 20th. Assuming that the infarct was uncomplicated, Which of the following cardiac biomarkers would most likely still be elvated and would assisit in an AMI diagnosis?

Troponin T

A REACTION IS IN______ KINETICS WHEN THE REACTION RATE DEPENDS ONLY ON ENZYME CONCENTRATION.

Zero order

All of the following are sources of serum ALP EXCEPT:

brains

Which two of the following biomarkers are not specific to cardiac muscle and may be elevated in patients with injury to muscle other than cardiac muscle?

CK-MB and myoglobin

All of the following statements concerning CK-MB (CK-2) are true Except:

CK-MB levels are normal in cardiac ischemia.

Which of the following cardiac biomarkers could detect a recent reinfarction?

Creatinine Kinase MB (CK-MB)

GGT (gamma glutamyl transferase) is an enzyme found in many body tissues including kidney, prostate, brain, pancrease, and liver, however, its clinical applications is confined to evaluation of what system?

Liver

An electrophorectic separation of lactate dehydrogenase isoenzyme that demonstrates elevation in LD-1 greater than LD-2 could be indicative of:

Myocardial infarction

What co enzyme does LD use when converting lactate to pyruvate?

NAD+

Which of the following conditions would be suggested by a jaundiced patient experiencing a marked rise in ALP, conjugated ilirubin, and a slight rise in ALP, conjugated bili, and a slight rise in alanine aminotransferase (ALT)?

Post-hepatic cholestasis

What accelerates the rate of lipase activity in the body?

Presence of bile salt