Final answer:
Cell signalling involves non-covalent interactions between ligands and receptors, initiating a chain of events that lead to a cellular response. This process is essential for coordinating cellular activities, and disruptions can cause disease. Cell signalling can be direct via gap junctions or at a distance, like hormones travelling through the bloodstream.
Step-by-step explanation:
The basics of cell signalling involve interactions of molecules called ligands with target cells that result in a cellular response. Non-covalent interactions are important in cell signalling as they dictate the binding of ligands to their specific receptors on the target cell without forming a permanent bond. Cells use different methods of signalling, such as direct contact through gap junctions or long-distance chemical signalling via hormones in the bloodstream. Specifically, in the framework of the Advanced Placement (AP) courses, understanding how cells communicate is akin to how we communicate with others. The signalling pathways enable an organism to coordinate complex processes such as metabolism, development, and disease response. Errors in these pathways can be detrimental, leading to various diseases. Cell signalling involves three stages: reception, signal transduction, and cellular response. During reception, ligands such as hormones travel and bind to receptors on target cells, initiating a series of reactions (signal transduction) that culminate in a specific cellular response.