Proteins are present in all the cells of our body and are considered to be the building blocks of life. They are actually large cells whose weight comprises a major constituent of the cells' dry weight. Inside the body, proteins are used for undertaking various functions ranging from supporting the cells to cellular locomotion and cell signalling. Their diverse functions notwithstanding, proteins are usually made up of a collection of 20 amino acids. There are various types of proteins and some of the examples include enzymes, antibodies and some varieties of hormones like insulin.

Generally, protein molecules are divided into two classes - fibrous proteins and globular proteins. Typically, fibrous proteins are long and insoluble. On the other hand, globular proteins are spherical in shape, usually compact and soluble. Fibrous as well as globular proteins may have one or many of the four different protein structures.

The four different protein structures include primary, secondary, tertiary as well as quaternary. It is important to note that the structure of a protein determines its specific function. For example, structural proteins like collagen and keratin are basically fibrous and chewy. On the other hand, globular proteins such as hemoglobin are compact and folded. Hemoglobin is present in the red blood cells (erythrocytes). This protein contains iron that attaches to oxygen molecules. The compact structure of hemoglobin is perfect for passing through the constricted blood vessels.

Our body synthesizes proteins via a process known as translation, which takes place in the cytoplasm. Translation entails delivering the genetic codes that accumulate when DNA is transcribed into proteins. In fact, cellular structures known as ribosomes facilitate the genetic codes to be translated into polypeptide chains. Subsequently, polypeptides chains go through many alterations prior to becoming completely functional proteins.

Protein functions

Proteins are essential for the body to build as well as repair the damaged tissues. People not receiving sufficient proteins through their diets may experience muscle wasting as well as various other symptoms. Workouts such as strength training often result in tiny tears in the muscles and when the body mends these tears, it leads to enlargement of the muscles. Proteins are also essential for the immune response that aids in healing the micro muscle tears. Nevertheless, consumption of excessive proteins does not help one to build up additional muscles.

Chemicals made by glands in any particular area of the body to facilitate activities as well as communicate with other body parts are known as hormones. Protein hormones attach themselves to receptors located on the cell membrane, rather than directly going into the cells. Insulin, oxytocin and other hormonal proteins play crucial roles in regulating the levels of blood sugar and, at the same time, promoting muscle contractions during childbirth. In addition, proteins also possess the aptitude to trigger muscle growth by means of augmenting protein synthesis or by reducing the breakdown of proteins.

Enzymes are also a type of protein that attaches to the molecules to accelerate chemical reactions. Enzymes too play crucial roles in several bodily activities like muscle relaxation and contraction. At the same time, they are responsible for transmission of nerve impulse. For instance, amylase and lipase are two enzymes that aid in digesting carbohydrates as well as fat. Another enzyme called ATPase takes out toxins from the cells. In addition, this enzyme is also necessary for adenosine triphosphate (ATP) breakdown, thereby releasing energy.

On the other hand, antibodies are specific protein configurations that present a particular immune defence against foreign substances invading the body. Our body produces antibodies when it comes in contact with particular antigens like viruses, bacteria and fungi. A type of protein called complement proteins back up the immune system as the body's second line of defence. These proteins possess the aptitude to perforate bacterial walls, encourage inflammation that assaults macrophages which eliminate invading micro organisms and also bind to the foreign substances invading the body.

During digestion, protein is broken down into simpler forms - amino acids, and it supplies the body with four calories for every gram. Incorporating proteins in your diet will help to give you a sense of being satiated and this will help you to keep fuller, thereby doing away with craving for food for a longer period. While protein can be used in the form of an energy source, the main source of energy for our body is carbohydrate. Eating diets which include lean proteins such as fish and beans, complex carbohydrates such as vegetables and whole grains and healthy fats like olive oil and avocados is considered to be the best means to supply our body with the requisite energy.