If the ATP-generating mechanisms in a cell are poisoned and the cell depletes its ATP reserves,which would occur first?
A)Primary active transport of molecules would cease.
B)Secondary active transport of molecules would cease.
C)Facilitated diffusion of molecules would cease.
D)Ion concentration gradients would reach equilibrium across the cell membrane.
E)All transport processes would cease immediately when the ATP was depleted.

Question

Quizplus · Accepted Answer

Primary active transport involves the energy from ATP directly to move molecules against their concentration gradient. Without a sufficient supply of ATP, primary active transport would cease first. Secondary active transport and facilitated diffusion both rely on existing concentration gradients, so they would continue until those gradients were depleted. The ion concentration gradient across the cell membrane would also be maintained for a short time due to other factors such as the Na+/K+ pump, but eventually would reach equilibrium as ATP is required to maintain this gradient. Therefore, option A is the best choice as it describes the process which would cease first.

If the ATP-Generating Mechanisms in a Cell Are Poisoned and the Cell