Question

You measure the concentration of a polar molecule inside and outside of a cell. You find that the concentration is high and gradually increasing inside the cell. You also measure the ATP concentration inside the cell and find that it is dropping. What would be your best hypothesis for the process that is occurring?

Select one:
a. facilitated diffusion
b. active transport
c. endocytosis
d. passive transport
e. simple diffusion

Answer 1

b. active transport

Step-by-step explanation:

Active transport moves the substances in living beings against the concentration gradients. To move a substance from the region of its higher concentration to that of its lower concentration, cells use energy. This energy-dependent transport of substances against their concentration gradient is called active transport.

In the given example, the observed substance is being moved towards inside of the cell where its concentration is already high. This means that the substance is being moved against its concentration gradient. A continuous drop in ATP levels reflects the use of ATP to move the substance from the surroundings to the inside of the cell. Therefore, the substance is being transported actively by the cell.