At various times throughout our lives we have been able to hear about the proteins on several occasions, but surely until now you are not very clear about what their basic characteristics are. To help you understand what characteristics represent proteins, here we present everything you need to know about them.
First of all, we can define proteins as macromolecules of amino acids that perform main functions within the human body and are present in foods that we consume within the framework of a Healthy dietThese nutrients are essential for maintaining the health of the skin, muscles, glands and other organs that make up our body.
What are proteins?
Proteins are complex structures made up of chains of amino acids, which are the basis of almost all fundamental biological processes. They are composed of carbon, hydrogen, oxygen, nitrogen and in some cases, other elements such as sulfur and phosphorus.
There are more than 20 types of amino acids, divided into essential amino acids (those that the body cannot synthesize on its own and must be obtained from food sources) and non-essential amino acids (that the body can produce).
- Essentials: histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine.
- Non-essential: alanine, arginine, asparagine, cysteine, glutamine, glycine, proline.
Proteins are vital for the structure and functioning of the human body, and therefore must be included in a balanced diet. The body requires a daily amount of protein that varies according to age, sex, level of physical activity, among other factors.
Protein functions
Proteins perform a wide variety of vital functions in the body:
- Structural: They are part of the structure of cell membranes, tissues and organs in the human body. Examples of structural proteins include collagen, which is responsible for the firmness of the skin, and keratin, which is part of hair and nails.
- Enzymatic: Many proteins act as enzymes, biological catalysts that increase the speed of chemical reactions in the body. An example is digestive proteins that help break down food.
- Regulatory: Regulatory proteins, such as insulin, control metabolic processes and the balance of body fluids.
- Defensive: Antibodies, which are part of the immune system, are proteins that defend the body from external infections.
The importance of amino acids
As mentioned, amino acids are the fundamental components of proteins. There are 20 types of amino acids linked together in long chains to form specific proteins. The sequence and combination of these amino acids determines the structure and function of each particular protein.
Classification of amino acids:
- Essentials: The body does not produce them, so we must obtain them from the diet.
- Non-essential: The body can synthesize them.
- Conditionals: They are necessary in times of stress or illness.
Essential amino acids can be obtained through foods of animal origin (meat, fish, eggs) and plant origin (soy, nuts, legumes).
protein classification
Proteins can be classified based on their form and biological value, that is, how the body uses them and whether they contain essential amino acids in sufficient quantities.
- Simple proteins: Composed only of amino acids.
- Conjugated proteins: Combined with other elements such as lipids or carbohydrates.
Biological value of proteins
The biological value of a protein refers to how efficiently the body uses it. Proteins from animal sources, such as meat and eggs, generally have a higher biological value, while those from plant sources, such as legumes, have a lower biological value.
For example:
- High biological value: present in meats, eggs, fish.
- Average biological value: They are found in cereals and legumes.
- Low biological value: present in vegetables and some fruits.
The importance of adequate protein consumption
The human body requires an adequate daily intake of protein. It is estimated that an average adult needs between 0.8 to 1 gram of protein per kilogram of body weight, depending on factors such as level of physical activity, gender, age and health status.
- Athletes may require up to 2 grams per kilo.
- Children, adolescents and pregnant women often require additional amounts of protein for proper development.
A protein deficiency can result in loss of muscle mass, poor physical performance and increased susceptibility to infections.
Signs of protein deficiency
A protein deficiency can cause a number of problems in the body, such as:
- Loss of muscle mass.
- Increased risk of infections.
- Weak nails and dry skin.
- Wear and tear of organs and tissues.
- Growth problems in children.
Food sources of protein
Protein sources can be classified into two large groups: animal origin and plant origin.
- Animal origin: Meat, fish, eggs, milk and dairy products.
- Plant origin: Legumes, soybeans, nuts and cereals.
In a balanced diet, it is advisable to combine animal and vegetable sources to obtain all the necessary amino acids.
Excess protein in the diet
Consuming too much protein, especially from animal sources, can have negative effects on health, such as increased cholesterol levels and overloading the kidneys. The body does not store excess protein, so it consumes what is necessary and the rest is discarded or converted into energy.
It is important to adjust protein consumption to the body's energy needs to avoid long-term health problems.
Proteins are essential for the growth, development and maintenance of the human body. Ensuring adequate protein intake through a balanced diet is essential for a healthy life.