This set of Enzyme Technology Multiple Choice Questions & Answers (MCQs) focuses on “Clinical Significance of Trypsinogen and Creatine Kinase”.
1. What does ‘X’ represent in the following reaction?
d) Creatine kinase
Explanation: In the above reaction ‘X’ represents creatine kinase which catalyzes the transfer of phosphate group of creatine phosphate to ADP to form ATP and creatine. The enzymes which are involved in transfer of aminoacids are referred to as transaminase. Proteinases are those that hydrolyze elastin and other protein present in extracellular matrix. Trypsinogen is a proteolytic digestive enzyme.
2. Which of the following clinical conditions, the activity of creatine kinase is not seen?
a) Muscular dystrophy
b) Muscle disease
d) Myocardial infarction
Explanation: Pancreatitis is a result of inappropriate activation of trypsinogen in pancreas. Creatine kinase activity increase is seen during muscular dystrophy and other muscle diseases. Creatine kinase is used as a diagnostic clue in myocardial infarction as it’s the first enzyme to be elevated.
3. Which of the following does not increase creatine kinase level?
b) Intramuscular injections
d) Vigorous exercise
Explanation: Macroamylsemia results due to an increase in plasma amylase with a decrease in urinary excretion, and not creatine kinase. Injuries, intramuscular injections and vigorous exercise increase the creatine kinase levels.
4. Which of this is not an isoenzyme of creatine kinase?
a) LDH5 (MMMM)
b) CK1 (BB)
c) CK2 (MB)
d) CK3 (MM)
Explanation: LDH5 (MMMM) is an isoenzyme of lactate dehydrogenase which is made of M-type polypeptide. CK1 (BB), CK2 (MB) and CK3 (MM) are isoenzymes of creatine kinase. CK1 (BB) is found in CSF, whereas CK2 (MB) and CK3 (MM) is found in plasma.
5. Ratio of plasma CK (MM3) and CK (MM1) is an indication of heart attack.
Explanation: CK (MM) has isoform CK (MM3) which is released from the cell and gets converted to CK (MM2) and CK (MM1). Later, CK (MM2) gets converted to CK (MM1). Hence the plasma CK (MM3) and CK (MM1) ratio is an indication of heart attack 2-5-hrs after the onset of chest pain.
6. __________ are proteolytic digestive enzymes which hydrolyze the peptide bonds between specific aminoacids.
d) α – amylases
Explanation: Endopeptidases are proteolytic digestive enzymes which hydrolyze the peptide bonds between specific aminoacids. Whereas exopeptidases cleave the peptide bond from the ends. Proteinases are those that hydrolyze elastin and other protein present in extracellular matrix. α-amylase hydrolyzes α-1,4 linkages in starch and glycogen to yield maltase.
7. Proteolytic digestive enzymes which hydrolyze the peptide bond from the ends are referred to as _________
Explanation: Proteolytic digestive enzymes which hydrolyze the peptide bond from the ends are referred to as exopeptidases. Endopeptidase hydrolyze the peptide bond between specific aminoacid. The enzyme that hydrolyze elastin and other protein present in extracellular matrix is proteinase. Transaminase are the enzymes which are involved in transfer of aminoacids.
8. Pick the odd one out.
d) Aspartate transaminase
Explanation: Aspartate transaminase is the odd one out as it a type of transaminases, which are involved in transfer of aminoacids. Trypsin, chymotrypsin, and elastase are examples of endopeptidases, which hydrolyze the peptide bonds between specific aminoacid.
9. Trypsinogen is activated by _________ enzyme.
b) α – amylases
Explanation: Trypsinogen is activated by enterokinase enzyme which is present in epithelial cells of duodenum. Transaminase are the enzymes that are involved in transfer of aminoacids. α-amylase hydrolyzes α-1,4 linkages, whereas proteinases hydrolyze elastin and other proteins.
10. Which of the following is an exopeptidase?
Explanation: Exopeptidases catalyze the hydrolysis of a peptide bond from the ends. Carboxypeptidase is an exopeptidase. Whereas trypsin, chymotrypsin, and elastase are examples of endopeptidases. Endopeptidases hydrolyze the peptide bonds between specific aminoacid.
Sanfoundry Global Education & Learning Series – Enzyme Technology.
To practice all areas of Enzyme Technology, here is complete set of 1000+ Multiple Choice Questions and Answers.
Participate in the Sanfoundry Certification contest to get free Certificate of Merit. Join our social networks below and stay updated with latest contests, videos, internships and jobs!