What are the protein functions?

Melanie Ramos 4 min. of reading Proteins Leave a comment

The main protein functions include providing energy to the body, the formation and repair of tissues and participating in the distribution of oxygen in the blood.
Other important protein functions include supporting the production of antibodies, facilitating the digestion of food by producing enzymes, regulating blood sugar levels and improving the assimilation of essential nutrients.

Why are they important?

Proteins are composed of long chains of amino acids, these components determine the functional capacity of proteins.

Of the 20 amino acids that exist, 9 are essential, which means that our body cannot produce them on its own, so they must be ingested through our diet.

Protein synthesis is a critical process for the development of our body’s vital functions. If we do not ingest enough essential amino acids, this synthesis will be limited, affecting our bodily functions.

7 Protein functions in the body

Proteins are responsible for shaping cell shape and structure and for captaining all the biochemical reactions that determine human metabolism. We can divide its intervention into several functions:

1. Defensive

Proteins are essential to the immune system, making up the antibodies that neutralise invading antigens, such as those that cause infections.

They are really important for maintaining the integrity of the cell membrane and some of them, such as:

Mucins provide a defensive barrier against bacteria.
Fibrinogen and thrombin promote blood clotting, essential to prevent bleeding.

2. Structural

Proteins make up cell membranes together with lipids, giving cells their shape and functionality.

They are involved in the repair and regeneration of damaged tissues, such as healing, bone formation and muscle regeneration.
They are essential building blocks of different tissues throughout the human body, such as keratin in nails and hair, actin/myosin in muscles, collagen in connective tissue and cartilage, and reticulin in subcutaneous tissue.

3. Regulatory

This is perhaps the most extensive area of protein functionality.

For it involves the multiplicity of biochemical processes that make it a reality:

Digestion.
Breathing.
Gas exchange.
Calcium and phosphorus metabolism.
Iron transport.
Cell mitosis and meiosis.
Energy utilisation by cells; and
Vital processes carried out by two types of proteins functionally identified as enzymes and hormones.

4. Enzymatic

Proteins with enzymatic function are the most specialised and numerous.

They act as biocatalysts, activating interactions between different substances called upon to produce energy or to synthesise a metabolite by accelerating the chemical reactions of metabolism.
Amylase specialises in breaking down starch ingested with vegetables to release glucose molecules, the simplest carbohydrate capable of being assimilated as an energy source by cells.

5. Hormones

Hormones, on the other hand, are proteins secreted by endocrine glands whose cells release them directly into the bloodstream to target specific receptors located on the membranes of other cells.

They are chemical modulators by transferring signals that condition a specific metabolic action.
Insulin secreted by the pancreas facilitates access of glucose to the cell cytoplasm.

6. Transport mechanics

Proteins play vital roles in the transport of nutrients and oxygen to cells and tissues, as in the case of haemoglobin and myoglobin.

Some are integrated into cell membranes acting as specific receptors for certain substances.

They contribute to the regulation of chemical and physical balances in the body, facilitating homeostasis, including the regulation of pH, electrolyte and osmotic balances.

7. Energetic

Although generally considered less relevant, the role of protein in energy production is notable, especially in situations of energy crisis due to malnutrition.

Normally, our body uses lipids and carbohydrates for energy. However, in times of shortage, you can turn to protein, getting 4 kilocalories of energy per gram of protein. This represents an alternative metabolic route, although it is not ideal because it can weaken the body by consuming internal proteins.

Note that certain proteins, especially those containing phosphate groups such as ATP, can act as energy reservoirs.

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