Answer:
They speed up chemical reactions. Without them you wouldn't be alive. They break down macromolecules, and also lower the amount of energy needed for a chemical reaction to happen.
Answer:
All of the above
Explanation:
I hoped I helped sorry if this isn't correct
Answer:
found lining many areas that contact the external environment
plays a role in protection
Explanation:
Explanation: Epithelial tissue is composed of cells laid together in sheets with the cells tightly connected to one another. Epithelial layers are avascular, but innervated. Epithelial cells have two surfaces that differ in both structure and function.