part of phagocytosis phagocytosis, recognition Note that cell surface molecules involved in the direct binding of bacteria may be also annotated to the molecular function term 'bacterial cell surface binding ; GO:0051635'. Note that cell surface molecules involved in the direct binding to opsonins such as complement components or antibodies may be also annotated to the term 'opsonin binding ; GO:0001846'. The initial step in phagocytosis involving adhesion to bacteria, immune complexes and other particulate matter, or an apoptotic cell and based on recognition of factors such as bacterial cell wall components, opsonins like complement and antibody or protein receptors and lipids like phosphatidyl serine, and leading to intracellular signaling in the phagocytosing cell. recognition of phagocytosed substance by phagocytic cell receiving