Final answer:
Tissue tropism is the propensity of viruses to infect specific types of tissue due to the presence of particular receptors on host cells, while specificity is a broader term referring to the unique interaction between biological entities, such as an enzyme's reaction to a substrate.
Step-by-step explanation:
Tissue Tropism vs Specificity
Tissue tropism refers to the tendency of most viruses to infect only certain tissue types within a host. This selective infection happens because viruses have evolved to recognize and bind to specific receptors on the surface of the cells of particular tissues. In contrast, specificity can refer to the general concept of an organism or pathogen being specifically adapted or suited to a particular host, cell type, or condition. The difference between tissue tropism and specificity lies in the context of their usage. Tropism is often used specifically to discuss the preferences of pathogens, like viruses, while specificity can refer to a broader range of biological interactions, including those outside of pathogen-host relationships.
For instance, tissue tropism is why certain cold viruses might only affect the upper respiratory tract, as they have receptors that only bind to cells in that area. On the other hand, specificity could also refer to how an enzyme only reacts with one substrate due to the shape of its active site.