definition of proteins

Proteins are complex molecules essential for the structure and function of cells. Its name comes from the Greek proteos which means fundamental, which is related to the important function they fulfill for life.

Proteins originate from the union of other molecules called amino acids, these are grouped in long chains and are kept stable by chemical bonds called peptide bonds.

Infinite possibilities

Amino acids are only of 20 different types and the way in which they are combined gives rise to each of the thousands of varieties of proteins. The various possible combinations of amino acids are encoded in DNA in the form of genes. Some amino acids in addition to coming from food can be produced by the body, another group are obtained only with food, which is why they are called essential amino acids.

Proteins can be of various types depending on the functions they perform in the body, however, they are broadly classified into structural proteins and proteins with biological activity. The proteins that we consume in the diet can be of either of the two types, regardless of their origin they are considered food proteins, the nutritional value of proteins is given by the greater or lesser presence of essential amino acids in their composition.

Structural Proteins

Structural proteins are those that intervene in the constitution of tissues, such as collagen, which is found as part of the skin, ligaments, tendons, bone and the matrix of various organs.

Proteins with biological activity, and their peculiarities

Proteins with biological activity are those that intervene or facilitate a biochemical process in the body, by intervening in several basic functions, such as:

Catalysts, here the most abundant type of proteins intervenes, enzymes, substances that have the function of allowing or accelerating a biochemical process, an example of this is digestive enzymes, necessary for the digestion of food in order to obtain from them the various nutrients.

Defenses, an important type of proteins are those that intervene in the body's defense functions called immunoglobulins, they are commonly known as antibodies.

Messengers, another group of proteins fulfill an important mission as chemical messengers to activate or inhibit processes both in places near and far from the site where they are produced, this is the case of hormones (such as insulin) and neurotransmitters.

GeneticsAnother important role of proteins is in the transmission of genetic information, by acting in the processes of DNA replication and synthesis of other proteins from the information encoded there.

Mechanical activity, two proteins are essential to be able to carry out the movements, they are actin and myosin present in the skeletal muscle to which they confer its contraction capacity.

TransportSeveral proteins are involved in the transport of various substances in the blood, such is the case of hemoglobin, a protein responsible for carrying oxygen to the tissues and collecting the carbon dioxide produced to take it to the lungs where it is eliminated; Another important plasma protein is albumin, an important regulator of colloid-motic pressure in the blood, which is necessary to maintain water in the vascular compartment, preventing it from leaking into the tissues, another important function of albumin is to transport various substances, including medicines.