What type of cellular transport moves molecules from low to high concentrations? A)proteins pumps
B)diffusion
C)osmosis
D)passive transport

A. Protein pumps

Explanation:

Molecules usually move down their concentration gradient - in other words, they move from high to low concentration.

Here, in the problem, we are moving molecules against their concentration gradient - from low to high. So, we require an input of energy.

Look at each of the answer choices:

A) Protein pumps

Protein pumps do require an input of ATP (energy), in order to push molecules up their concentration gradient. This is the answer.

B) Diffusion

Diffusion is the transport of molecules down their gradient, from high to low concentration, so this is wrong.

C) Osmosis

Osmosis is essentially diffusion of water molecules, so it's again from high to low concentration. This is wrong.

D) Passive transport

Like the name suggests, this transport is "passive", or it doesn't require energy. Because it doesn't require energy, we know it moves molecules down their concentration gradients. This is wrong.

The answer is thus A.

~ an aesthetics lover

answer; a muscle cell, another neuron and a of the above

the index of refraction of the second medium is higher. i just took the test trust me !