AP BIOLOGY

Detailed explanation-1: -Protein scaffolds are members of the signaling cascade downstream of cell surface receptors. Scaffold proteins help relay the message between the cell membrane and nucleus faster.

Detailed explanation-2: -Scaffold proteins organize cellular information flow Intracellular signaling pathways often use scaffold proteins. Canonical examples include Ste5, essential to the yeast mating MAPK pathway, and KSR, which directs signaling in the mammalian Ras-Raf-MEK-MAPK pathway.

Detailed explanation-3: -Signaling molecules are often called ligands, a general term for molecules that bind specifically to other molecules (such as receptors). The message carried by a ligand is often relayed through a chain of chemical messengers inside the cell.

Detailed explanation-4: -Scaffold proteins are proteins that simultaneously bind two or more other proteins, and organize binding partners into a functional unit to enhance signaling efficiency and fidelity.