AP BIOLOGY

Detailed explanation-1: -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-2: -The ligand is a chemical messenger released by one cell to signal either itself or a different cell. The binding results in a cellular effect, which manifests as any number of changes in that cell, including altering gene transcription or translation or changing cell morphology.

Detailed explanation-3: -A ligand is a molecule that binds another specific molecule, in some cases, delivering a signal in the process. Ligands can thus be thought of as signaling molecules. Ligands interact with proteins in target cells, which are cells that are affected by chemical signals; these proteins are also called receptors.

Detailed explanation-4: -As already noted, all signaling molecules act by binding to receptors expressed by their target cells. In many cases, these receptors are expressed on the target cell surface, but some receptors are intracellular proteins located in the cytosol or the nucleus.

Detailed explanation-5: -Within biochemistry, a ligand is defined as any molecule or atom that irreversibly binds to a receiving protein molecule, otherwise known as a receptor. When a ligand binds to its respective receptor, the shape and/or activity of the ligand is altered to initiate several different types of cellular responses.