Biology Basics: Homeostasis

Homeostasis
1. What is diffusion? What is osmosis?
Diffusion is the process by which substances spread from regions of high concentration to regions of low concentration. It is a method of passive transport, and thus costs the cell no energy. Electrically charged ions and large molecules will not diffuse freely across the membrane.
Facilitated diffusion is used for molecules that can't diffuse through the cell membrane because they are too large or not soluble in the lipid bilayer. Proteins in the membrane acts as channels and enable them to pass through more quickly. First, the carrier pr…