• Dr Ferraro

Amino acids. Part I

Updated: Feb 10, 2019

In the world of fitness, there are many athletes who regularly take supplements of various types including creatine, branched-chain amino acids (BCAA), protein powder and others.

Let us see then what BCAAs are and what effect these supplements have on our body. To do it we will start with the structure of the amino acids.

An amino acid is a molecule made of some fixed elements (carbon, hydrogen, oxygen and nitrogen) and other elements (including sulfur, iron and phosphorus) depending on the type of amino acid.

These particular molecules are partially produced by our body and partially introduced through food; Indeed, an essential amino acid is defined as an amino acid that cannot be synthesised by our body and need to be introduced by the diet. The essential amino acids are lysine, leucine, isoleucine, methionine, phenylalanine, threonine, tryptophan, valine and histidine.

All amino acids have in common a carboxylic group (COOH), an amino group (NH2) and a hydrogen atom (H) bound to the same carbon atom (C), but they differ from each other for the side chain, generically called group R. An amino acid will, therefore, has a chemical formula like the one in Picture 1.

Picture 1. Structure of an amino acid

However instead of R, you will find a specific chemical formula that is different for each amino acid, and it will allow you to identifying if it is a non-polar aliphatic groups, an aromatic groups, non-charged polar groups, a positively charged groups or a negatively charged groups.

Amino acids have different functions in our body, but the most important feature is the ability to join together in forming proteins, through peptide bonds. Hence, the amino acids can create extremely complex structures that are defined as primary, secondary, tertiary and quaternary.

The proteins perform many functions in our body: some have an enzymatic function, others have mechanical functions (e.g. cytoskeleton), others regulate the immune response, others intervene in the transmission of signals between cells, some control the cell division cycle, and others function as transporters of substances.

Without these molecules life, as we know it, most likely would not exist. This is why proteins are part of the small group of biomolecules (or "life molecules") along with lipids, carbohydrates and nucleic acids.

After this brief description of the structure and functional characteristics of amino acids, how do we define BCAA supplements? Does their recruitment during sports help performance? What are BCAAs actually for? Do they have a negative effect on the body?

In the following article, I will be addressed these questions, trying to debunk some false myths clarify how to use of BCAAs in sports.


Gigli D. Genetica pratica per l’esame di biologia. Volume Edizioni srl, Roma 2013.

Krane D. E, Raymer M. L. Fondamenti di Bioinformatica. Ed. Pearson, Pavia 2007.

Petsko G. A, Ringe D. Struttura e funzione delle proteine. Ed. Zanichelli, Bologna 2006.

#ferrarotrainer #research #blog #supplements #bcaa #protein #biology #research #creatine #Amino #acids #fitness #gym #workout #exercise #sport #diet #health #wellness

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University of Derby Kedleston Rd, Derby DE22 1GB,

Lecturer in Sport Therapy and Rehabilitation