Table of Contents
Protein Structure and Composition.
Proteins are compound nutrients that are large, complex and comprise smaller units referred to as amino acids. These amino acids are bonded by using peptides and create long chains. The body combines the various mixtures of amino acids to form proteins with certain functions. Proteins are made of carbon, hydrogen, oxygen, nitrogen and in rare cases nitrogen sulfur.
Their organization dictates the manner in which they are functioning within the body. Protein structure has four levels that begin with simple amino acid sequence through complex folded forms. It is significant to fold properly as the slightest change in structure may influence the functioning of a protein.
| Level | Explanation |
|---|
| Primary | Order of amino acids |
| Secondary | Helix or sheet shape |
| Tertiary | Final folded form |
| Quaternary | Multiple chains combined |
Types of Protein
The proteins are classified into various categories according to the nutritional content and biological purpose. Whole proteins provide all the essential amino acids and they are found primarily in animal foods. The incomplete proteins are those that do not contain all the essential amino acids and are prevalent in plant food. The structural proteins assist in the support of the body shape whereas the functional proteins assist in the support of the chemical reactions and body processes. There are proteins that are enzymes, hormones or antibodies. Diversity in the protein content in the food assists in meeting nutritional requirements and promotes growth, repair, and immunity.
Functions of Protein
There are numerous roles of proteins in the human body. They are useful in the building and repairing of muscles, skin, and organs. Enzymes that regulate metabolism and digestion are made using proteins. They also produce hormones which control the activities in the body as well as antibodies which prevent the infection. Proteins help in carrying oxygen and blood nutrients. Protein is a source of energy as well when required. Protein is necessary to maintain a healthy body and ensure growth and strength along with the immune system.
Dietary Sources of Protein
Protein is present in both plant and animal food. Animal sources tend to supply complete proteins whereas plant sources tend to need amalgamation to supply all the amino acids. Various protein-containing foods should be eaten to keep the muscles healthy and to sustain the immune system. Proteins of animal nature are meat, eggs, fish, and dairy. Legumes, nuts, seeds, whole grains form part of plant-based proteins. A healthy diet with a variety of protein sources enhances the intake of nutrients and the general health.
Protein Requirement
Protein requirements are age, body weight, physical activity, and health. The amount of protein required per kilogram of body weight is approximately 0.8 grams per kilogram of body weight or about 68 grams daily, in the case of most adults. Individuals that are physically active, pregnant or old tend to required large quantities. Adequate protein consumption can be used to keep the body muscles strong, facilitate recovery, and avoid nutritional deficiency. Distributing the protein consumption over the meals enhances digestion and uptake.
Protein Deficiency
Protein deficiency occurs when the body fails to obtain adequate protein in the diet. It may cause muscle weakness, fatigue, low immunity as well as slow healing. Protein deficiency may have an impact on growth and development in children. Extreme deficiency disorders are kwashiorkor and marasmus. The typical symptoms include hair loss, edema and frequent sickness. Normal protein consumption in proportional meals prevents vitamin deficiency and promotes normal body functions.
Protein and Special Populations.
Certain groups have special protein requirements owing to growth, age or physical activity. Protein is required by children to grow and develop well. The elderly need more protein to decimate muscle loss. Expectant and lactating mothers have extra protein requirements of developing the fetus and also to produce milk. Athletes require additional protein to repair and recover their muscles. Individuals having specific health issues might need to have modified protein consumption as prescribed by a doctor.