AP BIOLOGY

Detailed explanation-1: -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-2: -Types of Ligands Ligands are the signaling molecule used by the body for various cells to communicate with other cells.

Detailed explanation-3: -Ligands, which are produced by signaling cells and interact with receptors in or on target cells, come in many different varieties. Some are proteins, others are hydrophobic molecules like steroids, and others yet are gases like nitric oxide.

Detailed explanation-4: -Internal receptors, also known as intracellular or cytoplasmic receptors, are found in the cytoplasm of the cell and respond to hydrophobic ligand molecules that are able to travel across the plasma membrane.

Detailed explanation-5: -G-protein coupled receptors are usually found in the plasma membrane. The receptor binds a ligand from outside the cell. This binding causes a conformational change in the receptor such that the conformation of the cytoplasmic face of the receptor is altered.