T-cells possess T-cell receptors (TCRs) on their surface that bind to antigens, while antibodies are secreted by B-cells and circulate freely, marking antigens for destruction. Both TCRs and antibodies are similar in function, as they recognize antigens through specific epitopes, but they differ in structure and binding capabilities. TCRs are membrane-bound with a single binding site, whereas antibodies can have multiple forms with several binding sites. The distinction between antibodies and other binding molecules, such as ligands, can be blurred in practice, as both serve to recognize and bind to antigens. For further information on TCRs and antibodies, a recommended resource is the University of Washington's course website.
