Protein and amino acid

Introduction:

After water, protein is the most abundant substance in our body, making up about one-sixth of our body weight. One-third of this protein is found in muscles, one-fifth in bones and cartilage, one-tenth in the skin, and the rest in various tissues. Proteins, with their unique structures and functions, are essential to all plants and animals. They are vital for life as nucleic acids, which are made of proteins, are found in every cell.

Composition of Protein:

Proteins, like carbohydrates and fats, are composed of hydrogen, carbon, and oxygen. However, proteins also contain approximately 16% nitrogen and may include small amounts of other elements like iron, cobalt, and sulfur. Protein molecules are larger and more varied than those of carbohydrates and fats. Plants play a crucial role in protein synthesis by converting ammonia and nitrates from the soil into proteins, which herbivores then consume to fulfill their protein needs. Humans obtain proteins not only from plants but also from animal products like milk and meat.

Structure and Classification:

Proteins are made up of amino acids linked by peptide bonds, forming a chain with a free carboxyl group at one end and a free amino group at the other. These chains can be spherical or fibrous in shape.

A. Conjugated Proteins:

Conjugated proteins are combinations of simple proteins with non-protein components, forming complexes essential for various physiological functions. 1. Phosphoproteins: Found in milk (e.g., casein). 2. Lipoproteins: Proteins that bind to lipids, such as LDL, VLDL, and HDL in plasma. 3. Metalloproteins: Found in substances like ferritin and hemoglobin.

B. Simple Proteins:

Simple proteins hydrolyze into acids and include globulins, gluten, albumins, and albuminoids. Globulins and albumins are water-soluble and are found in blood, serum, and milk, while gelatin, a less soluble protein, is found in animals.

Function of Protein:

Proteins are vital for tissue formation and are key components of skin, bones, nails, teeth, and hair. They play a crucial role in muscle growth and repair. The human body consists of 19% fat, 17% protein, 60% water, and 4% minerals. Proteins provide the amino acids needed for the formation of new cells, which is essential for bodybuilding and overall cell structure.

Sources of Protein:

Plants are primary protein sources as they synthesize protein from water, nitrogen, and carbon dioxide. Animals rely on plants to meet their protein needs. Common protein sources include lentils, milk, eggs, meat, fish, cashews, oilseeds, chicken, and various crops.

Balanced Protein Intake:

To maintain a healthy diet, it is important to consume proteins from diverse sources, such as beans, milk, eggs, meat, fish, fruits, and vegetables. While legumes and grains are major protein sources, animal products like meat, fish, and poultry also play a significant role. Balancing protein intake from different sources ensures a well-rounded and nutritious diet.

Trending