AP BIOLOGY

Detailed explanation-1: -Juxtacrine signaling occurs between neighboring cells that are in physical contact with each other. In this case, the signaling molecule is not free, but is instead bound to the membrane of the cell. It may then interact with a receptor on the membrane of an adjacent cell.

Detailed explanation-2: -In juxtacrine interactions, proteins from the inducing cell interact with receptor proteins of adjacent responding cells. The inducer does not diffuse from the cell producing it. There are three types of juxtacrine interactions. In the first type, a protein on one cell binds to its receptor on the adjacent cell.

Detailed explanation-3: -Paracrine signaling involves the secretion of specific signaling factors by one cell which are perceived by corresponding receptors on another cell in the vicinity, triggering a response in it9, 10, whereas juxtacrine signaling requires direct contact between cellular components of the two cells involved11, 12.

Detailed explanation-4: -Juxtacrine signalling is a type of cellular communication between contacting cells, for example by means of gap junctions that allow for signalling molecules to pass from cell to cell. This type of interaction can be transitive, allowing distant cells to communicate with each other by successive cellular contacts.

Detailed explanation-5: -An autocrine signal is one that binds to receptors on the surface of the cell that produces it. Juxtacrine signaling involves contact between cells, in which a ligand on one cell surface binds to a receptor on the other.