Aspartic Acid

Aspartic acid is an acidic amino acid with functional groups of two carboxylic groups along with one amino group. There are about 20 important types of amino acids that are found in nature, more on this later. Every amino acid molecule is made up of two functional groups, they are opposite in characteristics, one is an amino group, and then there is a carboxylic acid. An aspartic acid structure is no exception; it contains one α-amino group which is in NH3+ forms and the carboxylic group that is in deprotonated –COO-. The aspartic acid formula looks like this- (C4H7NO4). Aspartic acid is a non-essential amino acid as the human body can synthesize it as it is needed.  Aspartic acid can be found in a plethora of eatables including oysters, avocado, sugar beets etc.

Why Is Aspartic Acid Different From Other Amino Acids?

As we previously discussed that amino acid has two functional groups, here we will dive a little deeper and shine some light on the third group, the R-group or the side chains, that gives the aspartic acid structure a distinction from the other amino acids such as glycine or cysteine. The R-group of the amino acids exerts profound changes in the biological activity of proteins. Amino acids are generally classified based on the characteristics of the functional group on the side chain in a neutral pH medium. They can be polar or nonpolar, polar yet charged, negatively charged or positively charged. The carboxyl group that is present in the side chain of the aspartic acid structure is ionized at physiological pH, which is known as aspartate, it is also from where the acid gets its name from. Glutamic acid also shares this sub-category with aspartic acid, the ionized carboxyl group in Glutamic Acid is known as glutamate.

Aspartic acid is a non-essential amino acid; it plays a vital part in the synthesis of amino acids and the citric acid and urea cycles. Aspartic acid commonly occurs in its L-form. It is found in plants and animals, especially in sugar beets and sugar cane. Here is a quick table consisting of the sources of this acid

Sources Of Aspartic Acid

Vegetable Sources

Animal Sources

Swamp Cabbage



Luncheon Meat

Sprout Seeds

Wild game

Oat flakes

Sausage meat

Aspartic Acid Structure And Types Of Aspartic Acid      

Aspartic acid is a dicarboxylic amino acid that means it is an acidic polar α-amino acid with two carboxylic groups and one of the carboxyl groups is attached with one additional methylene group. Aspartic acid has the isoelectric point of 2.77, because of these two carboxylic groups. It is also called ‘succinic acid’. The presence of the second carboxyl group makes it very hydrophilic, it has pKA of 3.85, and this group can also form an ionic bond with almost any metallic ion and also participate in a dipole interaction with water. As an aspartic acid molecule is negatively charged in neutral pH, it can be found at the surface of proteins. The carboxyl group bonded on alpha-carbon has a pKa value of 1.88; -COOH group at the side chain has the value of 3.65 and 9.60 for the amino group. The aspartic acid formula is C4H7NO4,  and the aspartic acid structure looks like this –

There are two enantiomers of the aspartic Acid, namely- L-aspartic Acid, D-aspartic Acid. There is not much difference between these two. The first one is directly incorporated into proteins, but D-aspartic acids are more limited. Enzymatic synthesis can produce either of these acids.

Aspartic Acid Hybridization

  • The molecular aspartic acid formula is HOOCCH(NH2)CH2COOH and has the molecular weight of 133.1g/mol.

  • Aspartic acid has the IUPAC name- 2-Aminobutanoic acid.

  • The atoms that are inside part of the aspartic acid have sp2 hybridization.

  • The nitrogen atom is touching three other atoms, i.e. one carbon and two hydrogen atoms. It is sp3 hybridized.

  • C1 and C4 are sp2 hybridized with trigonal planar geometry with 120o angle. The other two carbon atoms, i.e. C2 and C3, are sp3 hybridized with tetrahedral geometry in a 109o bond angle.

  • The carbon atoms in the carboxyl groups are sp2 hybridized.


  1. What Type of Acid is Aspartic Acid?

Answer: Aspartic acid is a non-essential acidic amino acid.

  1. What is The Aspartic Acid Formula and Its Molecular Weight?  

Answer: The chemical formula of aspartic acid is C4H7NO4 and its molecular weight is 133.1g/mol. 

  1. What Are The Two Functional Components of Aspartic Acid? 

Answer: The two functional components of aspartic acid are one amino group and two carboxyl groups. 

  1. What Are The Two Types of Aspartic Acid? 

Answer: There are two types of aspartic acid i.e. L-aspartic acid and D-aspartic acid. 

Did You Know

The aspartic Amino acid is a non-essential amino acid; in mammals, the synthesis of this amino acid is self-regulatory through the central metabolism pathway. You won’t be out of breath after running four yards if you eat oysters and avocados more since it has a significant level of aspartic amino acid. Amino acids are the building blocks for the proteins in your body.    

FAQ (Frequently Asked Questions)

1. What is aspartic acid used for?

Answer: Amino acids are the bricks used in building body proteins. Aspartic acid is a non-essential amino acid it means the human body can synthesize aspartic acid as it is needed.  There are two types of aspartic acid L-aspartic Acid and D-aspartic Acid. D-aspartic acid is used in body functions but not necessarily in the making of the body proteins. Aspartic acid is commonly used to reduce the feelings of tiredness, to boost the athletic capabilities or to increase the size and strength of the body muscles. D-aspartic acid can affect the level of testosterone in a male body playing a larger role in the development of male reproductive tissues.

2. Where is aspartic acid found?

Answer: Aspartic Acid can be composed in a human body as it is needed through metabolism. The aspartic acid formula is C4H7NO4. There are various sources from where aspartic acid can be acquired, such as vegetables or animal meats. In poultry products, beef products, sausages or in dairy products, the aspartic acid levels are much higher. In vegetable sources such as- sprouting seeds, oat flakes, avocado, sugar canes, molasses from sugar beets; in animal sources- oysters, luncheon meats, sausage meat, wild game, aspartic acid can be found. Intake of D-aspartic Acid can increase the level of testosterone to a significant level. However, some researches have failed to do so. It helps in the development of male reproductive tissues.