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What are Proteins? Functions and Types of Proteins

types of fats

Fine tuning the amount of protein included in the family diet is critical to growing and having a healthy and energetic body.


Proteins are macromolecules made up of a sequence of smaller molecules called amino acids . When we eat a food that contains proteins , our body breaks them down and breaks them into amino acids with which it then makes its own proteins . Some of the most important molecules of our body (enzymes, hormones, antibodies, etc.) are proteins that our body has develop from these amino acids.

There are different types of amino acids that we use for different purposes. Although some of them can be synthesized endogenously, but 10 of the amino acids we need to ingest them through food because our body cannot manufacture them. They are called essential amino acids .

Functions of proteins in the body

The proteins made by the body from different amino acids have determinant functions in our health in many different forms. Some of them are:

    • Structural

      One of the most important functions of proteins within our body is to serve as the framework and basis of our tissues and organs. Proteins are essential for building and repair of the bone and muscles , the skin , nails, blood vessels, lungs, etc …

    • Immune system

      Antibodies, which defend us against pathogens, are proteins . In fact, it is a compound made up of a protein and a carbohydrate called glycoprotein.

    • Enzymes

      The enzymes , a biochemical catalysts absolutely necessary in the physiological reactions of the organism, are also proteins . Enzymes are responsible for accelerating any chemical process within our body and the latest scientific studies proves that the amount and efficiency of enzymes within the body are determinants for life.

    • Others

      The list of functions performed by proteins to ensure life and health is very long . For example, hormones like insulin or melatonin are proteins. Others, such as hemoglobin, intervene in the transport of substances within the body. Other proteins allow muscle contraction or participate in the proper functioning of the nervous system, etc.

Digestion of proteins

The proteins cannot be used as presented in the food we eat  without a metabolic process . To be able to take advantage of them as nutrients and to dispose of the amino acids that the body needs to build its own proteins , the digestive system has to perform complicated processes that break down proteins , assimilate the amino acids and eliminate waste that is useless.

The first step in breaking down protein ingested with food is in the stomach , thanks to an enzyme called pepsin . To work effectively, this enzyme needs a very acidic environment. This acid environment is achieved thanks to gastric glands that secrete hydrochloric acid, which acidifies the gastric juice thus allowing the breakdown of proteins.

Later, in the small intestine , the pancreas secretes other enzymes that end up decomposing them into amino acids ready to be absorbed.

Absorption of amino acids

In the small intestine, proteins already in the form of amino acids are absorbed by the intestinal blebs to reach the blood capillaries. Through the circulatory system , these amino acids will reach the cells that need them to make the different types of specific proteins in our body.

When we do not chew well or when we eat food pieces that are too large for enzymes break them down, these proteins cannot be metabolized or used and will continue through the large intestine and anus until they are expelled in the feces. Discover the importance of chewing food well .

Manufacture of other proteins

The liver is one of the key organs in the manufacture of new proteins . In order to make a new protein with our DNA , it is necessary for the cell to have all the necessary amino acids in the correct proportions . If any of them are missing, or there is not enough of it, the protein can not be manufactured.

The remaining amino acids , or those that cannot be used, are removed in the form of urea via the urine . The problem is that the metabolism of proteins, that is to say, this complex process through which the organism destroys them to absorb amino acids, is a process of great energetic and enzymatic expense that also leaves very toxic residues in our body. That’s where problems arise when it comes to ingesting too much protein.


Proteins of animal origin

When it is said that animal proteins have a high biological value, it means that animal proteins (which have a DNA more similar to ours than vegetables) contain an amount of amino acids very similar to that which our body needs to build their own proteins.

That is, the body needs a number of amino acids to build its endogenous proteins . Well, the proteins contained in animal flesh contain all the necessary amino acids and in the correct amounts . This does not mean that these same amino acids can not be found in the plant kingdom and in the quantities needed. What it means is that, in order to be able to use vegetable protein in an optimal way, it is necessary to know the foods that contain them well and know how to combine them properly, while eating meat is a faster and more practical way of achieving the same purpose.

The problem with animal proteins is that they acidify the system and this can cause serious health problems . The consumption of meat increases the level of proteins in the blood and its metabolism leaves nitrogenous residues that acidify the system in general. When the body can no longer use more, it must get rid of those amino acids through the urea, but the kidneys are not always able to cope with the amount of toxic substances to eliminate. Excessive consumption of meat is related to some of the diseases of our society such as heart problems, cholesterol , cancer, etc.

Plant proteins

Vegetables are an extraordinary source to provide us with the amino acids we need. The problem or inconvenience is that the vegetables do not have the necessary amount  percentages. But it is an inconvenience with an easy solution. In order to be able to nourish ourselves with the essential amino acids, it is necessary to combine the different foods of plant origin that, in short, contain all those amino acids . That is, in order to provide our body with a healthy way to supply itself with efficient protein, we must have some knowledge about it and put it into practice.

There are a multitude of protein vegetables with different amino acids and nutritional properties, but, in general, we can incorporate the essential amino acids into our diet with a simple trick: combining 75% of cereal with 25% of legume .

If every day, in the main meal, we make sure to eat a dish that contains 75% of some cereal (such as brown rice , buckwheat, quinoa, millet, oats, etc.) Lenguages, azukis, etc …) we are making sure to ingest the amount of amino acids the body needs to perform its functions in an optimal way.

The vegetable protein does not leave as much residue as the one of animal origin in the process of metabolism and generally containing less amount of amino acids, it is difficult to exceed and therefore to acidify the system.

Anyway, if you are one of those people who find it  very difficult to be vegetarian, a good alternative to meat is fish . It does not contain as much protein as meat, is simpler to metabolize and also contains essential fatty acids very beneficial to the cardiovascular system.

We must not forget that, although they are essential, the amount of protein the body needs daily is low compared to carbohydrates. A good percentage of macronutrients is 15% protein, 55-60% carbohydrates and 25-30% fat.

Seen all of the above, we can drill down with knowledge in the great debate on whether  protein diets  are good or bad for healthy and definitely slimming .

You can learn more about protein by reading about protein overdose .


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