Difference Between Choline and Acetylcholine

The key difference between choline and acetylcholine is that choline is a nutrient present in both animals and plants, whereas acetylcholine is a neurotransmitter present in animals.

Although these two terms sound related, there is a significant difference between choline and acetylcholine, including their chemical structure, occurrence, uses, etc. However, it is important to note that choline is the precursor for acetylcholine.

CONTENT

1. Overview and Key Difference
2. What is Choline 
3. What is Acetylcholine
4. Side by Side Comparison – Choline vs Acetylcholine in Tabular Form
5. Summary

What is Choline

Choline is an organic compound, which serves as an essential nutrient in both plants and animals. It is a vitamin-like nutrient. Further, it is a constituent in lecithin, which is a fatty substance that occurs in plant and animal bodies. The structure is as follows:

Further, this compound naturally occurs in some food and is also available as a dietary supplement. It can act as a source of methyl groups we need for some steps in the metabolism. Additionally, choline and metabolites that originate from this compound serve in our body in three different ways:

1. Structural integrity plus signalling in cell membranes
2. Acetylcholine synthesis
3. Source of methyl groups

Moreover, our body can synthesize choline via methylation of phosphatidylethanolamine in the liver. In addition, the dietary sources for choline include raw beef liver, cauliflower, large eggs, broccoli, spinach, etc.

What is Acetylcholine?

Acetylcholine is an organic compound that serves as a neurotransmitter in our body. Therefore, it can send signals between nerve cells and other cells as a chemical message. It is an ester of acetic acid and choline. Here, the oxygen atom of choline molecules is acetylated. Furthermore, this compound has a highly polar ammonium group. Therefore, this compound cannot penetrate through the lipid membrane.

Besides, this compound is synthesized in certain neurons in the presence of an enzyme called choline acetyltransferase. Here, the reactants are choline and acetyl Co-A.

What is the Difference Between Choline and Acetylcholine?

Choline is the precursor for the production of acetylcholine because acetylcholine is the choline that has been acetylated at its oxygen atom. The key difference between choline and acetylcholine is that choline is a nutrient present in both animals and plants, whereas acetylcholine is a neurotransmitter present in animals.

Moreover, a further difference between choline and acetylcholine is that when considering the chemical structures, choline contains an ammonium group having a positive charge and four substituents on the nitrogen atom while, in acetylcholine, the oxygen atom of choline is acetylated

Summary – Choline vs Acetylcholine

Choline is the precursor for the production of acetylcholine because acetylcholine is the choline that has been acetylated at its oxygen atom. The key difference between choline and acetylcholine is that choline is a nutrient present in both animals and plants, whereas acetylcholine is a neurotransmitter present in animals.

Reference:

1. “Office of Dietary Supplements – Choline.” NIH Office of Dietary Supplements, U.S. Department of Health and Human Services, Available here.

Image Courtesy:

1. “Choline-skeletal” By Benjah-bmm27 – Own work (Public Domain) via Commons Wikimedia
2. “Acetylcholine” By Harbin – Own work (Public Domain) via Commons Wikimedia