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 are often used as building blocks of larger, complex carbohydrates. 2  The empirical structure of simple carbohydrate is C 6 H 12 O 6 or (CH 2 O) 6 while that of complex carbohydrate is (C 6 H 10 O 5) n, in which ânâ is the number of monomer units.
Carbohydrates: Simple versus Complex. Simple carbohydrates are sugars. All simple carbohydrates are made of just one or two sugar molecules. They are the quickest source of energy, as they are very rapidly digested. Complex carbohydrates may be referred to as dietary starch and are made of sugar molecules strung together like a necklace or branched like a coil. They are often rich in fiber, thus satisfying and health promoting.