Q36 - A Luciferase Reporter Measures Caspase Activity in Apoptosis

Theoretical B Real exam question - full text reproduced under IBO's CC BY-NC-SA 4.0 license

Cell Junctions, Extracellular Matrix & Cell Death

Sir Alastair Currie (1921-1994), Sir John Sulston (1942-present) and colleagues discovered how cells can commit controlled suicide (apoptosis). Apoptosis is executed by Caspase enzymes. Cyclohexamide (CH), which inhibits ribosomes, was used to induce apoptosis in cells treated with the hormone bone morphogenetic protein-9 (BMP9). To measure the number of apoptotic cells after treatment, inactive luciferase substrate, and the light-emitting enzyme luciferase, were added.

Figure 1 for Q36: A Luciferase Reporter Measures Caspase Activity in Apoptosis

This question mixes multiple-choice/numeric-estimate parts with True/False statements - answer each part using the information and data above.

A. BMP9 treatment causes an increase in apoptosis.

B. A large excess of both inactive substrate and luciferase is required to give a linear luminescence signal in response to caspase activity.

C. Caspase gene expression is increased during apoptosis.

D. After subtracting blanks, comparing 0 ng/ml to 5 ng/ml BMP9 (readings: blank 110, untreated 1450, CH+BMP9 550), what is the nearest percentage change in caspase activity?

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Question reproduced from IBO 2017, Theoretical Exam B, licensed under CC BY-NC-SA 4.0 - attributed to the International Biology Olympiad. Open the full exam PDF · Official answer key & worked solutions