Health and Beauty

Basic functions of proteins in the body

Proteins are biomolecules found in all living organisms. They are involved in a wide range of chemical processes essential for life. Proteins are found in hair, skin, and connective tissue. They regulate digestion, cellular activity and oxygen transport throughout the body.

All proteins are made up of amino acids linked together and forming long chains. About twenty different amino acids make up proteins, and proteins with similar composition and structure have similar functions.

But what are the functions of proteins? The main function of proteins can be classified into one of the following six general categories:

  1. Ensuring the structural role.
  2. Regulating bodily processes.
  3. communications ;
  4. fluid balance;
  5. Participation in immunity;
  6. Energy saving.

There are many types of proteins in the human body, each with a different function. Keratin is a type of protein that makes up hair, skin, and nails. It helps build the leather and protects it from scratches or tears. Collagen is the most abundant protein in the human body. It is found in bones, muscles, skin and connective tissue, where it provides strength and structure. Enzymes are proteins that help speed up chemical reactions in the human body, such as digestion. Some hormones, such as insulin, are proteins that regulate functions in the human body. Hemoglobin is a protein found in red blood cells, and helps transport oxygen in the human body.

Protein composition

Proteins are composed of amino acids. Amino acids are elements that contain an amine group and a carboxyl group, as shown in the figure below. Proteins consist of long chains of amino acids, linked together by a special bond called a peptide bond. A bond is formed between the amino group of one amino acid and the carboxyl group of another amino acid. This bond continues with several amino acids to form a polypeptide chain, which is a protein.

Chemical structure of amino acid.
Image rights © Adobe Stock

Amino acids are differentiated by R groups shown in the diagram. The amino acid sequence then determines the structure of the protein. The three-dimensional structure of a protein is determined by the hydrogen bonds that form between polypeptide chains. Depending on this arrangement, proteins will fold into different shapes, allowing them to perform their function. The three-dimensional structure of the protein is shown below.

Protein structure
From amino acids to protein.
Image rights © Adobe Stock

Main functions of proteins

What are the functions of proteins? The main functions of proteins are to provide structure, regulate body processes, transport substances, balance fluids, contribute to immunity, and provide energy. Each different function is associated with a different type of protein, or several types of proteins.

building

Structural proteins are a type of protein responsible for forming cells and supporting major structures, such as hair, skin, and bones. There are many structural proteins in the human body. Two of the most common are collagen and keratin.

Collagen is a structural protein found in bones, connective tissue and skin. It is strong and fibrous and makes up about a third of the proteins in the human body.

Keratin is also a structural protein found in hair, nails, and skin, as well as in the linings of organs and glands. The amino acid composition of keratin is different from that of collagen, giving them different functions.

to organize

Proteins regulate many processes in the body. Enzymes are a type of protein that speed up the speed of chemical reactions, including digestion and DNA replication. Without enzymes, these chemical reactions necessary for life would occur very slowly. Protein hormones also regulate body mechanisms. Hormones are actually responsible for sending messages throughout the body to regulate cell activity. For example, insulin is a protein hormone that regulates metabolism by promoting cellular uptake of glucose.

communications

Another function of proteins in the human body is to transport various elements. Transport proteins move ions or molecules across cell membranes. For example, hemoglobin is a protein found in red blood cells.

It is a transport protein that helps transport oxygen from the lungs to the cells. When a person breathes, oxygen molecules in the air pass from the lungs into the bloodstream. In the bloodstream, oxygen molecules bind to hemoglobin, which then transports them to other tissues in the body. Hemoglobin also helps transport carbon dioxide out of the body. This process is called breathing.

Fluid balance

Regulating fluid balance in the body is one of the processes provided by proteins. Fluid balance represents the ratio of fluid input and output that allows the metabolism to function. It is necessary in the human body. If fluid balance is not maintained, it may lead to dehydration which can cause problems with heart and kidney function.

Proteins called albumin and globulin are produced in the liver and help maintain fluid balance by attracting and holding water in the blood. Albumin also acts as a transport protein for enzymes and hormones in the blood. Globulin also plays an important role in the functioning of the liver and immune system.

immunity

Proteins also play an important role in the immune system. The immune system in the human body is a large network containing many types of cells, organs, tissues, and proteins that protect against unwanted foreign elements, such as bacteria and viruses.

The first step in the immune response is the detection of harmful antigens or foreign substances. This detection is carried out by special proteins called molecular pattern recognition receptors (PRR). After recognizing the antigen, the immune system releases antibodies. Antibodies are another type of protein that neutralizes antigens. Different antibodies are produced for different antigens, so they all have slightly different compositions.

The immune system also produces other proteins to help fight disease or infection. These include complement system proteins and interferons. Complement system proteins stimulate inflammatory responses and help fight inflammation. Interferons are signaling proteins released near virus-infected cells. This signal encourages neighboring cells to strengthen antiviral defenses.

Energy saving

Protein can also be used to provide energy. Carbohydrates are used as the main source of energy in the human body. It decomposes very easily and is therefore quickly converted into energy. Fats are also a source of energy, but they are digested much more slowly than carbohydrates. However, when carbohydrate or fat intake is insufficient, the human body breaks down protein to provide energy, which can happen if a person is on a crash diet.

Proteins are broken down into amino acids and nitrogen. The amine group is used for energy, and the nitrogen is converted to urea and excreted by the kidneys. Urea is a toxic substance and its excessive production puts more stress on the kidneys. Therefore, using protein as fuel can have long-term harmful effects on the body.

Basic functions of proteins in the body

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