Amino acids are the building blocks of proteins, which play a crucial role in various biological functions, including structural components of cells, enzymes that catalyze biochemical reactions, hormones, and antibodies, among others.
In total, there are 20 standard amino acids that are used by the human body to synthesize proteins. These amino acids can be categorized into two groups:
-
Essential Amino Acids: There are 9 essential amino acids that the body cannot synthesize and must be obtained through diet. These are:
- Histidine
- Isoleucine
- Leucine
- Lysine
- Methionine
- Phenylalanine
- Threonine
- Tryptophan
- Valine
-
Non-Essential Amino Acids: There are 11 amino acids that the body can synthesize on its own, and thus are not required to be obtained from dietary sources. These are:
- Alanine
- Arginine
- Asparagine
- Aspartic acid
- Cysteine
- Glutamic acid
- Glutamine
- Glycine
- Proline
- Serine
- Tyrosine
In addition to these standard amino acids, there are also others known as "modified amino acids" or "non-standard amino acids" that may play roles in specific proteins or functional processes. However, the basic building blocks of proteins in the human body primarily consist of the 20 standard amino acids.