Final answer:
The main chemical classes of neurotransmitters are amines, amino acids, and neuropeptides. Triglycerides are not a class of neurotransmitters; they are a type of fat and serve as an energy store for the body.
Step-by-step explanation:
The main chemical classes of neurotransmitters include amines, amino acids, neuropeptides, and others such as acetylcholine or biogenic amines like serotonin. These neurotransmitters play crucial roles in the communication between neurons in the nervous system. Amines are derived from amino acids and include biogenic amines like serotonin, but lose their carboxyl groups in the process. Amino acids such as glutamate, GABA (gamma-aminobutyric acid), and glycine are also neurotransmitters, each with distinct systems and receptors. Neuropeptides, like met-enkephalin and beta-endorphin, are larger molecules made of chains of amino acids and can also act as hormones.
However, triglycerides do not belong to the class of neurotransmitters. Triglycerides are a type of fat found in the blood and are an important energy store for the body, but they are not involved in neurotransmission. Therefore, option a. triglycerides is not one of the main chemical classes of neurotransmitters.