Protein Class
Protein compounds are chain-like structures composed of amino acids and are formed in living cells. Proteins are components of structural and supportive substances, hormones, and enzymes and are therefore indispensable for the existence and nutrition of all living beings.
Occurrence of Proteins
Simple proteins include albumins. These are blood serum proteins that also occur in milk and egg whites. Simple proteins (proteins) are also found in grains.
Structural proteins, such as keratin, are present in nails, hooves, feathers, and hair. In gelatin (glue), there is gluten and collagen. These are mainly found in connective tissue. Simple proteins are only distinguished by their solubility. Among the complex protein compounds, the proteids, belong to others the blood pigment and milk casein. These complex proteins contain at least lipids, carbohydrates, or other substances.
Functions of Protein
As already mentioned, proteins have various functions within living cells and are therefore essential for all living beings. Among these are the supportive and protective functions. They are active in bones, cartilage, and skin. Due to their contracting properties, they also serve the production of mechanical force. This is achieved through myosin, the muscle protein. They maintain the oncotic pressure in the blood. Oncotic pressure refers to the pressure that protein bodies exert on a semipermeable membrane.
Furthermore, proteins have a protective function against pathogens and the antibodies formed from them. They help with wound healing and also perform transport functions such as hemoglobin does. In their hormonal function, they regulate the organism.
Deficiency Symptoms Caused by Lack of Protein
According to recommendations from the German Society for Nutrition, adults should consume approximately 0.8 grams protein per kilogram of body weight daily. The need is slightly higher in children and adolescents as well as pregnant women and older people. In our society, protein deficiency symptoms are rarely seen because the regular intake of food covers the necessary protein supply.
In poor countries where hunger and hardship prevail, however, diseases caused by a lack of protein often occur. For example, one sees images of children with pronounced potbellies. This is an external sign of excessive water accumulation in cells. Also hair loss, poor wound healing, growth disorders, muscle weakness, and the occurrence of fatty liver are part of it. Chronic protein deficiency without help inevitably leads to death.
With a normal and sensible mixed diet that contains about 100 grams of protein per day on average in our society, the protein content is sufficiently secured.