Protein

Proteins are complex molecules that form an essential part of the human body. They are actively involved in enhancing the physical and chemical processes of the human body by working on the tissues and organs. Twenty types of amino acids are arranged in combinations to form a variety of proteins. 

Jons Jacob Berzelius coined the term protein in 1938. The word comes from Proteios, meaning “holding first place”. Every species has proteins. 

Sources of Protein

1. Seafood: Seafood is an excellent source of protein because it has a low-fat content. Fish such as salmon are higher in fat content and also carry omega-3 fatty acids suitable for heart health.

2. White-meat poultry: Dark meats have higher fat content than lighter ones. It is better to remove their skin as it is full of saturated fat. White meats are full of lean protein and, hence, are better.

3. Milk, cheese, and yoghurt: Dairy foods are great protein sources. They also contain vital minerals like calcium and vitamin D. Skim or low-fat dairy helps keep bones, teeth, and gums strong to prevent osteoporosis. 

4. Eggs: Eggs are rich in protein. 

5. Beans: Apart from being rich in protein, plant-based sources like beans also have a beneficial amount of fibre in them. This fibre helps to keep the stomach full longer. One-and-a-half cups of beans contain 29 gm of protein.

6. Soy: Just 50 gm of soy protein every day can help lower cholesterol by about 3%. It is an excellent alternative to animal-based protein.

7. Lean beef: It contains 2 gm more saturated fat than a skinless chicken breast. Moreover, it contains zinc, iron, and vitamin B12.

8. Almonds: Along with good protein content, they are rich in fibre, vitamin E, manganese, and magnesium.

9. Oats: Oats are rich in protein and provide healthy fibre, magnesium, manganese, vitamin B1, and other nutrients.

10. Tuna: One tuna can contain around 27gm of protein. It is low in fat and contains omega-three fats.

Functions of Protein

Proteins are made of amino acids joined together like a string of beads. There are almost 20 amino acids that help form numerous proteins. Proteins perform a wide variety of functions in the human body. 

Here are some of the main functions of protein:

• They play a major role in the growth and maintenance of tissues. The body breaks down the protein to form tissues. However, at times, the amount of protein broken down is more than what has been created, increasing the body’s need. 

• Proteins are also required to carry out the biochemical reactions inside the body.

• Proteins also act as messengers and aid communication between different body parts. 

• They provide structural integrity to the cells and support them. 

• They play a significant role in boosting the immune response and help maintain the body’s pH. 

• Proteins are a big source of energy for the body, and hence, they are an essential part of the body’s nutritional requirements.

Structure of Protein

In 1953, Max Perutz proved for the first time that protein has a specific arrangement of amino acids along its chain.

In 1958, Frederick Sanger presented the primary structure of insulin which contains 51 amino acids and is made up of two polypeptide chains held together by disulphide bonds.

Primary Structure of Protein

It is the ultimate determinant of the complete conformation of a protein. The primary structure of proteins is a result of years of mutation and selection. The primary structure of proteins is directed by the DNA coding sequence for it in the genome.

Secondary Structure of Protein

As the progression of protein synthesis takes place, the interactions start among the nearby amino acids. This gives rise to local patterns, also known as the secondary structure. These secondary structures involve β-strands and α- helix.

 Tertiary Structure of Protein

This is the three-dimensional structure of protein that is also the most stable. High temperature denatures this structure.

Quaternary Structure of Protein

This level of structure refers to the spatial arrangement of the polypeptide subunits and the nature of the interaction between them. These interactions may be covalent links. For example, the disulphide bonds or non-covalent interactions like electrostatic forces, hydrogen bonding and hydrophobic interactions.

Conclusion

Protein is the building block of the human body. It carries out several functions, including processing chemical reactions via enzymes, creating and recreating DNA, balancing hormones in the body, strengthening a healing immunity system, carrying out muscle movements, breaking down the nutrients absorbed by the body, and supplying energy. 

In addition, protein can conduct highly complex chemical processes in the body. New dietary supplements like Whey and plant-based proteins are used as supplements to meet the protein needs of the body.