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.
1 Simple carbohydrates-Examples of simple carbohydrates include dairy products, candy, baked goods, fruit, and processed sugars. 2  Complex carbohydrates-Examples include rice, corn, flour, whole grains, and legumes.