SAT Subject Biology Practice Question 461: Answer and Explanation
11. Questions below refers to the following experiment involving human liver cells.
Aspartate aminotransferase (AAT) is an enzyme produced in liver cells that catalyzes an important step in the metabolism of amino acids. The production of AAT is dependent upon various hormonal stimuli. Human liver cells were cultured; half the cultured cells were used to measure the amount of AAT mRNA present, and half were used to measure the amount of AAT present. Measurements were taken at five-minute intervals following hormonal stimulation of the cells.
Figure 1 shows the results of this experiment.
The experiment was repeated, this time adding an inhibitor of protein synthesis along with the hormone.
Figure 2 shows the results of this experiment.
Figure 1 sh
A. induce protein synthesis
B. induce RNA transcription
C. induce DNA replication
D. inhibit protein synthesis
E. induce cell division
Correct Answer: B
B By looking at the two figures, you should be able to eliminate choices C, D, and E, because these processes are not monitored in the experiment. Because mRNA transcription is the first process to occur after addition of hormone, it seems likely that this is the process the hormone is stimulating.