Question 1

A phosphotransferase enzyme that has increased activity when injury,inflammation,or necrosis of skeletal muscle occurs is:

Accepted Answer

The enzyme referred to in the question is creatine kinase (CK), which is found in high concentration in skeletal muscle. Its activity increases in response to skeletal muscle injury, inflammation or necrosis, making it a valuable marker for muscle damage. ALP (alkaline phosphatase), ACP (acid phosphatase), and LD (lactate dehydrogenase) are not specific for skeletal muscle damage and may be elevated in a variety of conditions.

Question 2

MATCHING
Match the enzyme with its correct enzyme classification.
-Hydrolase

Accepted Answer

Alkaline phosphatase is a hydrolase enzyme, which means it catalyzes the hydrolysis of phosphomonoesters, releasing phosphate in the process.

Question 3

Match the enzyme with its correct substance required for enzyme reaction.Answers may be used more than once,once,or not at all.
-Pyridoxal phosphate

Accepted Answer

Pyridoxal phosphate is a coenzyme of aspartate aminotransferase, which is involved in the transamination process, facilitating the conversion of aspartate and alpha-ketoglutarate to oxaloacetate and glutamate.

Question 4

Certain muscle relaxants are hydrolyzed by CHE during surgical procedures.If an individual with the atypical (E^a)gene variant is exposed to this relaxant,what would occur?

Accepted Answer

The atypical gene variant (E^a) associated with cholinesterase (CHE) would likely result in decreased enzyme activity. This would lead to decreased metabolism of muscle relaxants that are hydrolyzed by CHE, potentially causing prolonged paralysis, including of the respiratory muscles, due to the sustained presence of the relaxant.

Question 5

Which one of the following statements concerning lipase (LPS)is incorrect?

Accepted Answer

Lipase is actually a more specific diagnostic finding than amylase in the diagnosis of acute pancreatitis. Therefore, statement A is incorrect.

Question 6

Match the enzyme with its correct substance required for enzyme reaction.Answers may be used more than once,once,or not at all.
-Calcium

Accepted Answer

Amylase requires calcium ions for its activity and stability.

Question 7

MATCHING
Match the enzyme with its correct enzyme classification.
-Transferase

Accepted Answer

Creatine kinase is a transferase enzyme that transfers a phosphate group from ATP to creatine, forming phosphocreatine. Lactate dehydrogenase is an oxidoreductase enzyme that catalyzes the conversion of lactate to pyruvate. Alkaline phosphatase is a hydrolase enzyme that hydrolyzes phosphate esters.

Question 8

The recommended assay,because of its specificity and sensitivity for the measurement of the activity of the CK-MB isoenzyme,is the:

Accepted Answer

The monoclonal sandwich immunoassay is the recommended assay for the measurement of the activity of the CK-MB isoenzyme because it has high specificity and sensitivity. In this assay, two monoclonal antibodies against different epitopes of the CK-MB isoenzyme are used to sandwich the target protein, allowing for accurate measurement of its activity. The other options listed may not have the same level of specificity and sensitivity.

Question 9

Which of the following statements is incorrect concerning creatine kinase (CK)?

Accepted Answer

CK catalyzes the conversion of creatine phosphate and ADP to creatine and ATP, not the other way around.

Question 10

A severely hemolyzed serum specimen from an individual with hemolytic anemia is received in the laboratory with a request for total CK and LD enzymes.How will the results of these analyses be falsely affected by the condition of the specimen?

Accepted Answer

Hemolysis can release intracellular enzymes such as lactate dehydrogenase (LD) and creatine kinase (CK) into the serum, artificially increasing their levels in the blood sample.

Question 11

Match the enzyme with its correct substance required for enzyme reaction.Answers may be used more than once,once,or not at all.
-Magnesium

Accepted Answer

Creatine kinase requires magnesium as a cofactor for its enzymatic activity.

Question 12

MATCHING
Match the enzyme with its correct enzyme classification.
-Oxidoreductase

Accepted Answer

Lactate dehydrogenase is classified as an oxidoreductase because it catalyzes the transfer of electrons from lactate to NAD+, resulting in the formation of NADH and pyruvate.

Question 13

Because your immunoassay analyzer is down for maintenance,you have performed an immunoinhibition assay to determine the relative presence of CK isoenzymes in an individual who has presented with acute upper body pain.The assay reveals a strong activity after inhibition of CK-M subunits using a monoclonal antibody.This result indicates:

Accepted Answer

The strong activity after inhibition of CK-M subunits suggests the presence of CK-B subunits, which can be found in various tissues, making the result nonspecific.

Question 14

The usefulness of analyzing lipoprotein-associated phospholipase A₂ for the identification of individuals at risk for future cardiovascular events is because of its:

Accepted Answer

Lipoprotein-associated phospholipase A2 (Lp-PLA2) is upregulated in atherosclerotic plaques, particularly complex plaque. Complex plaque is more prone to rupture and associated with acute cardiovascular events, making Lp-PLA2 a useful biomarker for identifying individuals at risk for future cardiovascular events. A, B, and C are not accurate descriptions of the role of Lp-PLA2 in cardiovascular risk.

Quiz 19: Serum Enzymes

A phosphotransferase enzyme that has increased activity when injury,inflammation,or necrosis of skeletal muscle occurs is:

MATCHING Match the enzyme with its correct enzyme classification. -Hydrolase

Match the enzyme with its correct substance required for enzyme reaction.Answers may be used more than once,once,or not at all. -Pyridoxal phosphate

Certain muscle relaxants are hydrolyzed by CHE during surgical procedures.If an individual with the atypical (E^a) gene variant is exposed to this relaxant,what would occur?

Which one of the following statements concerning lipase (LPS) is incorrect?

Match the enzyme with its correct substance required for enzyme reaction.Answers may be used more than once,once,or not at all. -Calcium

MATCHING Match the enzyme with its correct enzyme classification. -Transferase

The recommended assay,because of its specificity and sensitivity for the measurement of the activity of the CK-MB isoenzyme,is the:

Which of the following statements is incorrect concerning creatine kinase (CK) ?

A severely hemolyzed serum specimen from an individual with hemolytic anemia is received in the laboratory with a request for total CK and LD enzymes.How will the results of these analyses be falsely affected by the condition of the specimen?

Match the enzyme with its correct substance required for enzyme reaction.Answers may be used more than once,once,or not at all. -Magnesium

MATCHING Match the enzyme with its correct enzyme classification. -Oxidoreductase

The usefulness of analyzing lipoprotein-associated phospholipase A₂ for the identification of individuals at risk for future cardiovascular events is because of its:

Quiz 19: Serum Enzymes

A phosphotransferase enzyme that has increased activity when injury,inflammation,or necrosis of skeletal muscle occurs is:

MATCHING Match the enzyme with its correct enzyme classification. -Hydrolase

Match the enzyme with its correct substance required for enzyme reaction.Answers may be used more than once,once,or not at all. -Pyridoxal phosphate

Certain muscle relaxants are hydrolyzed by CHE during surgical procedures.If an individual with the atypical (Ea) gene variant is exposed to this relaxant,what would occur?

Which one of the following statements concerning lipase (LPS) is incorrect?

Match the enzyme with its correct substance required for enzyme reaction.Answers may be used more than once,once,or not at all. -Calcium

MATCHING Match the enzyme with its correct enzyme classification. -Transferase

The recommended assay,because of its specificity and sensitivity for the measurement of the activity of the CK-MB isoenzyme,is the:

Which of the following statements is incorrect concerning creatine kinase (CK) ?

A severely hemolyzed serum specimen from an individual with hemolytic anemia is received in the laboratory with a request for total CK and LD enzymes.How will the results of these analyses be falsely affected by the condition of the specimen?

Match the enzyme with its correct substance required for enzyme reaction.Answers may be used more than once,once,or not at all. -Magnesium

MATCHING Match the enzyme with its correct enzyme classification. -Oxidoreductase

The usefulness of analyzing lipoprotein-associated phospholipase A2 for the identification of individuals at risk for future cardiovascular events is because of its:

Certain muscle relaxants are hydrolyzed by CHE during surgical procedures.If an individual with the atypical (E^a) gene variant is exposed to this relaxant,what would occur?

The usefulness of analyzing lipoprotein-associated phospholipase A₂ for the identification of individuals at risk for future cardiovascular events is because of its: