Understand the concept of membrane-bound receptors: These are proteins located on the cell membrane that bind to external molecules, initiating a cellular response.
Identify the types of receptors listed: Cytosolic receptors are found in the cytoplasm, nuclear receptors are located in the nucleus, and mitochondrial receptors are found in mitochondria.
Recognize that G protein-coupled receptors (GPCRs) are a type of membrane-bound receptor: They are integral membrane proteins that play a key role in signal transduction.
Learn how GPCRs function: When a ligand binds to a GPCR, it activates the receptor, which then interacts with a G protein, leading to a cascade of cellular events.
Conclude that among the options provided, the G protein-coupled receptor is the membrane-bound receptor, as it is located on the cell membrane and involved in transmitting signals from outside the cell to the inside.