CVS Practice Test

The process when extracellular substances bind to a receptor and cause a change in function is known as signal transduction. This refers to the series of molecular events and cellular processes that occur as a result of the binding of a ligand (the extracellular substance) to a receptor. Essentially, signal transduction pathways transmit signals from outside a cell to its interior, leading to various cellular responses, such as changes in gene expression, enzyme activity, or cellular behavior.

Signal transduction is crucial in numerous biological processes, including growth, immune responses, and neuronal communication. The binding of a ligand to a receptor activates the receptor, which then undergoes a conformational change. This change triggers a cascade of signaling events inside the cell, often involving secondary messengers and other proteins that help amplify and propagate the signal, resulting in a precise and coordinated cellular response.

In contrast, other options like cell signaling, receptor interaction, and synaptic transmission involve broader concepts or more specific contexts but do not specifically focus on the entire process that follows ligand-receptor binding as signal transduction does. Cell signaling encompasses various mechanisms, receptor interaction typically refers to the binding activity itself, and synaptic transmission specifically deals with communication between neurons. Therefore, signal transduction accurately captures the intended process of how