Usage and Grammar
Q. Is changing and to or in the following sentence necessary grammatically? “Ghrelin does not bind and activate GHSR.”
A. This is not actually a grammar issue. Both and and or are grammatical in the sentence. But the truth of your statement may change if you change and to or. “Ghrelin does not bind and activate GHSR” means that ghrelin does not do both actions, but it might bind without activating, and it might activate without binding. “Ghrelin does not bind or activate GHSR” means that ghrelin does not do either action.