Definition of Protein 

Proteins, which are amino acid chains, are the building blocks of life and are found in every cell of the human body. Proteins are involved in everything from muscle growth and repair to enzyme, hormone, and antibody production. Below is a list of some of the main functions your proteins will be performing within your body. 

Blog Key Takeaways 

• Proteins are the building blocks of life and are found in every cell of the human body. 

• They are essential for the growth, repair, and maintenance of the body's tissues. 

• Protein plays a vital role in maintaining muscle mass and preventing sarcopenia. 

• Some proteins are fibrous and provide stiffness and rigidity to cells and tissues, such as keratin, collagen, and elastin. 

• Proteins support the immune system by forming immunoglobulins (antibodies) to fight infections.

• They act as hormones, chemical messengers that aid communication between cells, tissues, and organs. 

• Proteins transport molecules and nutrients throughout the bloodstream and within cells. 

• Enzymes are proteins that play a vital role in catalysing thousands of biochemical reactions inside and outside of cells. 

• They also have storage functions, such as storing iron.

• Protein plays a vital role in regulating the concentrations of acids and bases in the blood and other bodily fluids. 

• Proteins can provide the body with energy in extreme circumstances. 

Protein Supports Repair of Body Tissue 

Protein is essential for the growth, repair, and maintenance of the body's tissues. At times, the body breaks down more protein than it can produce, increasing its requirements. This is most common during illness, pregnancy, and breastfeeding. People recovering from injury or surgery, older adults and athletes also require more protein. 

Protein Helps us Maintain Muscle Mass 

Protein is crucial for maintaining muscle mass, which is important for maintaining mobility and independence. Sarcopenia is the gradual loss of skeletal muscle that occurs as we get older, starting around 50 years old. Consuming the recommended daily protein amount can help preserve muscle mass and strength. 

Proteins Provide Structure 

Some proteins are fibrous and provide stiffness and rigidity to cells and tissues. Keratin, collagen, and elastin are examples of proteins that help form the connective framework of various structures in the body. Keratin is a protein found in the skin, hair, and nails that serves as a structural protein. Collagen is the most abundant protein in the body, serving as a structural protein in bones, tendons, ligaments, and skin. Elastin is several hundred times more flexible than collagen, and its elasticity allows many tissues in the body, such as the uterus, lungs, and arteries, to return to their original shape after stretching or contracting. 

Protein Bolsters our Immune Health 

Protein is required for the formation of immunoglobulins, also known as antibodies, which are responsible for fighting infections. Antibodies are blood proteins that work to protect the body from harmful invaders like bacteria and viruses. This process results in the development of immunity to diseases to which the body is exposed. 

Proteins act as Messengers 

Proteins also function as hormones, which are chemical messengers that help cells, tissues, and organs communicate with one another. Hormones are classified into three types: proteins and peptides, steroids, and amines. The most common type of hormone is protein and peptides, which are made from chains of amino acids. The sex hormones testosterone and oestrogen are made from steroids, which are derived from cholesterol. Amines, which are formed from the individual amino acids tryptophan or tyrosine, aid in the production of sleep and metabolism-related hormones. Some common examples of hormones include: 

• Insulin: signals the uptake of glucose into the cell. 

• Glucagon: signals the breakdown of stored glucose in the liver. 

• hGH (human growth hormone): stimulates the growth of various tissues, including bone. 

• ADH (antidiuretic hormone): signals the kidneys to reabsorb water. 

• ACTH (adrenocorticotropic hormone): stimulates the release of cortisol, a key factor in metabolism. 

Proteins Transport Molecules and Nutrients 

Transport proteins are essential for transporting substances throughout the bloodstream, into and out of cells, and within cells. These substances include vitamins and minerals, as well as blood sugar, cholesterol, and oxygen. Hemoglobin, for example, is a protein that transports oxygen from the lungs to the body's tissues, whereas glucose transporters (GLUT) transport glucose to the cells. Lipoproteins are in charge of transporting cholesterol and other fats throughout the body. These transport proteins are highly specific, which means they will only bind to certain substances and will not move others. A protein transporter that moves glucose, for example, will not move cholesterol. Aside from transportation, proteins have storage functions, such as ferritin, which stores iron, and casein, which is the primary protein in milk that aids in baby growth. 

Proteins Help with Metabolic Reactions 

Enzymes are proteins that play an important role in the thousands of biochemical reactions that take place both inside and outside of cells. Their distinct structure enables them to bind with other molecules inside the cell, known as substrates, and catalyse metabolic reactions. Digestive enzymes like lactase and sucrase, which aid in sugar digestion, are examples of enzymes that can function outside of the cell. Certain enzymes require other molecules, such as vitamins or minerals, to function properly. Some bodily functions that rely upon enzymes include the following: 

• Digestion 

• Energy production 

• Blood clotting 

• Muscle contraction 

Proteins Maintain Fluid Balance 

Proteins are essential for regulating body processes and maintaining fluid balance. Albumin and globulin, proteins found in blood, aid in fluid balance by attracting and retaining water. If a person does not consume enough protein, their albumin and globulin levels will eventually fall, resulting in an inability to keep blood in the blood vessels. This causes fluid to move into the spaces between cells, resulting in swelling or edoema, particularly in the abdomen. This condition, known as kwashiorkor, is a type of severe protein malnutrition that occurs when a person consumes enough calories but not enough protein. Kwashiorkor is uncommon in developed regions of the world, but more common in areas where starvation is widespread. 

Protein Balances our pH Levels 

Proteins are essential for maintaining the acid-base balance in the blood and other bodily fluids. The pH scale, which ranges from 0 to 14, measures the balance of acids and bases, with 0 being the most acidic, 7 neutral, and 14 being the most alkaline. Because even small changes in pH can be harmful or potentially fatal, the body maintains normal pH ranges through a variety of buffering systems. Proteins, such as haemoglobin, a protein found in red blood cells, are one way the body regulates pH. Hemoglobin binds small amounts of acid, assisting in the maintenance of normal blood pH. Phosphate and bicarbonate are two other buffer systems in the body. 

Protein Supports Energy Production 

Proteins can give the body energy, not that you'd want that however. Protein, like carbohydrates, has four calories per gram, while fat has the most energy at nine calories per gram. However, the body prefers to use carbohydrates and fats as energy sources because it stores these nutrients for fuel and they are metabolised more efficiently than protein. Proteins only contribute a small amount of energy to the body under normal conditions. When you fast for 18 to 48 hours without eating, your body breaks down skeletal muscle to release amino acids that can provide energy. Furthermore, if carbohydrate storage is depleted as a result of strenuous exercise or insufficient calorie consumption, the body will use amino acids from broken-down skeletal muscle for energy.