Thekey differencebetween amino acid and imino acid is thatan amino acid contains an amino group and a carboxylic group together in the same molecule whereas an imino acid contains an imino group and a carboxylic group together.
尽管术语氨基酸和氨基酸听起来相似，但它们是我们用两种不同的术语来命名两种不同的化合物。氨基酸是proteins. Imino acids are also related to amino acids since we can convert an amino acid into an imino acid.
CONTENTS
1.Overview and Key Difference
2.What is Amino Acid
3.What is Imino Acid
4.Side by Side Comparison – Amino Acid vs Imino Acid in Tabular Form
5.概括
What is Amino Acid?
An amino acid is an organic molecule which acts as the building block of proteins. It essentially contains anaminegroup (-NH2), carboxylic group (-COOH),alkyl group(-R) and a hydrogen atom (-H) attached to the same central carbon atom. Therefore, the chemical elements in an amino acid are carbon, hydrogen, oxygen, and nitrogen. Sometimes, there is sulfur as well.
Figure 01: Different Amino Acids
If the amine group and carboxylic group of the amino acid are attached to the first carbon atom of the carbon chain, we call it an alpha amino acid. Often, the term amino acid refers to alpha amino acids since they are abundant. There are 22 amino acids involved in protein formation. We call them “proteinogenic amino acids”.
Among them, nine proteinogenic amino acids areessential amino acidsfor us because our body cannot produce it. Therefore, we need to take them from outside, i.e. food sources. Other amino acids can be produced in our body; thus, there is no need to take them from outside.
What is Imino Acid?
An imino acid is an organic compound containing an imino group and a carboxylic group together. We can denote imine group as (>C=NH). Therefore, unlike in amino acids, these molecules have a double bond between carbon and nitrogen atoms.
Figure 02: Imine Group Attached to Carbon
Some enzymes can convert amino acids into imino acids. For instance,D-amino acid氧化酶是这样的酶。此外，脯氨酸包含一个二级胺基（我们称之为亚胺），而不是主要胺基。因此，我们称脯氨酸为“伊米诺酸”。
What is the Difference Between Amino Acid and Imino Acid?
An amino acid is an organic molecule which acts as the building block for proteins while an imino acid is an organic molecule having an imine group. Hence, the key difference between amino acid and imino acid is that an amino acid contains an amino group and a carboxylic group together in the same molecule whereas an imino acid contains an imino group and a carboxylic group together.
Moreover, the chemical bond between the central carbon atom and the nitrogen atom of amino group in amino acids is a single bond while the bond between the central carbon atom and the nitrogen atom of imine group is a double bond. So, we can consider this also as a difference between amino acid and imino acid.
概括– Amino Acid vs Imino Acid
Most people confuse the two terms amino acid and imino acid thinking they are the same. However, there is a distinct difference between amino acid and imino acid. The key difference between amino acid and imino acid is that an amino acid contains an amino group and a carboxylic group together in the same molecule whereas an imino acid contains an imino group and a carboxylic group together.
Reference:
1. N.V. Bhagavan, Chung-Eun Ha, in Essentials of Medical Biochemistry (Second Edition), 2015
Image Courtesy:
1. “Molecular structures of the 21 proteinogenic amino acids” By Dan Cojocari – Own work(CC BY-SA 3.0)viaCommons Wikimedia
2. “Imine-(primary)-skeletal” By Hbf878 – Own work (CC0) viaCommons Wikimedia
发表评论