What type of protein helps molecules move through a
cell membrane?

Water channel proteins are helps the molecules move through a cell membrane.

Explanation:

this protein  acts like a pore in the membrane that lets water molecules or small ions through quickly. This proteins (aquaporins) allow water to diffuse across the membrane at a very fast rate. Ion channel proteins allow ions to diffuse across the membrane.

Explanation:

the eggs seems to be rotten because when we add enough salt into water the density of water becomes greater than that of egg ,hence the floats and seems to be rotten