Question

Researchers conducted an experiment to investigate the effects of a valinomycin treatment on skeletal muscle cells. Valinomycin is a naturally occurring substance that can be used as a drug. The results of the experiment are presented in the table.

Relative Rates of ATP Production
Time after Treatment: 5 min, 10 min
Untreated Cells: 1.0, 7.7
Valinomycin-Treated Cells: 0.3, 2.7

Which of the following claims about the effects of the valinomycin treatment is best supported by the data presented in the table?

a) Valinomycin enhances ATP production in untreated cells.
b) Valinomycin reduces ATP production in treated cells.
c) ATP production remains constant over time in untreated cells.
d) ATP production decreases over time in valinomycin-treated cells.

Answer 1

The correct option is (b) Valinomycin reduces ATP production in treated cells. The experiment's data best supports the claim that valinomycin reduces ATP production in treated skeletal muscle cells, as seen by lower rates of ATP production in valinomycin-treated cells compared to untreated cells.

Step-by-step explanation:

The data presented from the experiment indicates that the addition of valinomycin to skeletal muscle cells affects ATP production. By comparing untreated cells at both 5 and 10 minutes, which had ATP production rates of 1.0 and 7.7 respectively, to valinomycin-treated cells, which had production rates of 0.3 and 2.7 at the same time points, it's clear that valinomycin-treated cells exhibit reduced ATP production.

Valinomycin works by transferring K+ ions, which can disrupt osmotic pressure across cellular membranes, potentially interfering with processes that contribute to ATP production. Since ATP is essential for both contraction and relaxation of skeletal muscle fibers, the reduction in ATP observed in the presence of valinomycin suggests a compromised capacity for these cells to perform work necessary for muscle contraction and other cellular processes.