Answer:
1. Carbohydrates and fats both - can be used as an energy source by organisms.
Carbohydrates provides quick energy while fats are stored energy. If there is no sufficient carbohydrates to provide energy, then the stored fats come to use.
2. Enzymes are proteins that speed up reactions by - Lowering the amount of energy required.
Enzymes are proteins that speed up reactions by reducing the activation energy needed to get them to work. They play a vital role in bodily functions like digestion.