Help me please I have no idea

The small molecule cyclic amp (camp) takes about 0.2 second to diffuse 10 μm, on average, in a cell. suppose that camp is produced near the plasma membrane on one end of the cell; how long will it take for this camp to diffuse through the cytosol and reach the opposite end of a very large cell, on average? assume that the cell is 200 μm in diameter.

Kudzu vines grow by climbing and wrapping around trees. trees covered by kudzu can die because they are starved of sunlight. what type of relationship exists between the trees and the kudzu growing on them?

Which of the following requires the use of energy and the of transport proteins to move a molecule across a cell membrane?