3. What is an enzyme and what is its role in a reaction?

An enzyme is a protein that serves as a catalyst in a reaction. Enzymes help to speed up the rate of the reaction by lowering the initial activation energy (the minimum amount of energy needed to undergo a reaction).

a motor homunculus represents a map of brain areas dedicated to motor processing for different anatomical divisions of the body.

homunculus represents the importance of various parts of your body as seen by your brain. as a result, they take up a lot of brain space. although the cortical homunculus is a curiosity, penfield's work in mapping the brain's relationship to the body was invaluable.

there's the proffessional site that will you.