AP BIOLOGY

Detailed explanation-1: -Peripheral membrane proteins are found on the outside and inside surfaces of membranes, attached either to integral proteins or to phospholipids. Unlike integral membrane proteins, peripheral membrane proteins do not stick into the hydrophobic core of the membrane, and they tend to be more loosely attached.

Detailed explanation-2: -Receptors are generally transmembrane proteins, which bind to signaling molecules outside the cell and subsequently transmit the signal through a sequence of molecular switches to internal signaling pathways.

Detailed explanation-3: -Beta-barrels composed of a single polypeptide chain OmpA-like transmembrane domain (OmpA) Virulence-related outer membrane protein family (OmpX) Outer membrane protein W family (OmpW)

Detailed explanation-4: -Some proteins in the plasma membrane form open pores, called membrane channels, which allow the free diffusion of ions into and out of the cell. Others bind to specific molecules on one side of a membrane and transport the molecules to the other side.