What Role Does the Phospholipid Bilayer Play in Cellular Transport?

The phospholipid bilayer is central to various types of cellular transport, including passive transport, active transport, and vesicular transport. In passive transport, substances move across the membrane without the use of energy, typically through diffusion or facilitated diffusion. In active transport, energy is required to move substances against their concentration gradient. Vesicular transport involves the movement of larger molecules via vesicles, which can either fuse with or bud off from the membrane.