What is the Difference Between Serine and Threonine?

Serine and threonine are two types of hydroxyl-containing amino acids that contain an α-amino group. They differ in several aspects:

• Structure: Serine has a side chain consisting of a hydroxymethyl group, while threonine has a side chain consisting of a hydroxyl group. Threonine also has a methyl substituent in place of one of the hydrogens on the β carbon.
• Essentiality: Serine is a non-essential amino acid, meaning it can be synthesized in the human body under normal physiological conditions, while threonine is an essential amino acid, which must be obtained through the diet.
• Synthesis: Serine is synthesized from glycine, while threonine is synthesized from aspartate.
• Function: Serine participates in the metabolism of purines and pyrimidines, while threonine converts to pyruvate.
• Occurrence: Serine is found in lamb, eggs, edamame, liver, pork, sardines, salmon, seaweed, and tofu, while threonine is found in poultry, cottage cheese, fish, meat, lentils, black turtle bean, and sesame seeds.
• Codons: The codons that encode serine are UCU, UCC, UCA, UCG, AGU, and AGC, while the codons that encode threonine include ACU, ACC, ACA, and ACG.

In summary, serine and threonine are two hydrophilic amino acids with different structures, essentiality, synthesis, functions, and dietary sources.

Comparative Table: Serine vs Threonine

Here is a table comparing the differences between serine and threonine:

Serine and threonine are both proteinogenic amino acids with uncharged polar side chains. The main difference between them is that serine is a non-essential amino acid, while threonine is an essential amino acid. Serine has a side chain containing a hydroxymethyl group, whereas threonine has a side chain containing a hydroxyl group.