What causes scientific knowledge to change over time

As time goes on, more evidence is found for all sorts of subjects which can either prove a point or debunk it.

lysosomes contain a variety of enzymes, enabling the cell to break down various biomolecules it engulfs, including peptides, nucleic acids, carbohydrates, and lipids (lysosomal lipase). the enzymes responsible for this hydrolysis require an acidic environment for optimal activity. hope i !

the cell cycle is the final answer! : )