Water, carbon dioxide, and oxygen are among the few simple molecules that can cross the cell membrane by diffusion (or a type of diffusion known as osmosis ). Diffusion is one principle method of movement of substances within cells, as well as the method for essential small molecules to cross the cell membrane.
living bodies must be able to carry supplies in and out of cells in order to control homeostasis and retain cell processes operating efficiently. Following are the common supplies that every human body is required to carry in and out:
Water
Inhale oxygen and exhale carbon dioxide.
take in proteins, carbohydrates, vitamins, fats and take out waste materials.
