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.
The body breaks down carbohydrate into glucose (a type of sugar) to provide energy. The number of sugars found in the chemical structure of the carbohydrate determines if it is a simple or a complex carbohydrate. Simple carbohydrates contain no more than two sugars. Carbohydrates with more than two sugars in their structures are considered complex carbohydrates. Compared to simple carbohydrates, complex carbohydrates are generally absorbed slower and thus take longer for the body to digest. This helps to avoid blood glucose spikes.