Proteins are biomolecules formed by linear chains of amino acids.
Proteins can be classified into simple proteins, formed only by amino acids or their derivatives.
Proteins play a vital role for life and are the most versatile and diverse biomolecules. They are essential for the growth of the organism and perform a huge amount of different functions.
All proteins have carbon, hydrogen, oxygen and nitrogen, and almost all of them also have sulfur.
Proteins are long chains of amino acids linked by peptide bonds.
Dietary sources of protein include meat, eggs, legumes, nuts, cereals, vegetables and dairy products such as cheese or yogurt. Both animal and vegetable protein sources possess the 20 amino acids necessary for human nutrition.
Protein deficiency is a major cause of disease and death in the third world. Protein deficiency plays a part in the disease known as kwashiorkor. . Protein deficiency can lead to reduced intelligence or mental retardation.
Excess of protein consumption
As the body is unable to store the proteins, the excess protein is digested and converted into sugars or fatty acids. The liver removes nitrogen from amino acids, a way that they can be consumed as fuel, and nitrogen is incorporated into urea, the substance that is excreted by the kidneys. These organs can usually deal with any additional overload, but if kidney disease exists, a decrease in protein will often be prescribed.
Excessive protein intake can also cause loss of body calcium, which can lead to long-term loss of bone mass. However, several protein supplements are supplemented with different amounts of calcium per serving, so they can counteract the effect of calcium loss.