Explain how the folding of the mitochondrial inner membrane and the many individual chloroplast thylakoids are beneficial to a cell that is carrying out chemical reactions.

It allows for an increased exposed surface area and hence a faster rate of reaction between the reacting agents and the organelles.

Explanation:

Chemical reaction is dependent on the surface area of contact between the reacting parties. Having a folding surface as seen in many cell organelles gives an advantage of increasing the surface area available for contact between the reacting agent and the organelles. This ensures that reaction is faster and more effective.