Amino Acid Structure and Protein Classification

Amino Acids and Proteins

• Proteins that contain all essential amino acids are termed complete proteins.
• The conversion of amino acids into other forms occurs primarily in the liver.
• The human body requires nine essential amino acids during adult life.

Essential and Non-Essential Amino Acids

• Non-essential amino acids are those that the body can synthesize and are not required in the diet.
• Two essential amino acids needed only during infancy are histidine and arginine.

Functions of Proteins

• Proteins play a crucial role in building and repairing tissues, forming enzymes, hormones, and other body chemicals.
• The quality of a diet can be improved by combining different protein sources to provide all essential amino acids.

Dietary Combinations

• A common food combination that enhances diet quality includes legumes and grains.

Functions of Specific Proteins

• The main function of haemoglobin is to transport oxygen in the bloodstream.
• Collagen is identified as a key protein in connective tissue.

Properties of Proteins

• Wheat flour is suitable for making bread or chapati due to its gluten content, which provides elasticity.
• The carboxyl group of an amino acid exhibits acidic properties.

Protein Classifications

• Conjugated proteins are formed when simple proteins combine with non-protein substances.
• Simple proteins are composed mainly or solely of amino acids without any non-protein components.
• Proteins that are easy to digest and contain essential amino acids are often referred to as high-quality proteins.
• The products of digestion of simple conjugated proteins are known as peptides.
• In classification, haemoglobin belongs to the category of globular proteins.

Learn about the general structural formula of amino acids, the properties of amino acid molecules, and how amino acids form proteins through peptide linkage. Explore the classification of proteins based on physical and chemical properties as well as amino acid content.