However, in the form of N2, nitrogen is unusable by all organisms except for a few primitive bacteria that are capable of converting N2 gas to ammonia (NH3). This process of conversion is called nitrogen fixation, and makes the nitrogen available for use by organisms.
1 Simple carbohydrates have very simple chemical structures and are made of small molecules. 2  Complex carbohydrates have very complex structures while the molecules are large, unlike simple carbohydrates.
Carbohydrates provide your body with glucose it needs to function properly. Two types of carbohydrates exist: complex carbohydrates and simple carbohydrates. Complex carbohydrates take time to break down into glucose. Foods rich in complex carbohydrates and fiber are called good carbohydrates.