Definitions [7]
Define α-amino acids.
α-Amino acids are carboxylic acids having an amino (–NH2) group bonded to the α-carbon, that is, the carbon next to the carboxyl (–COOH) group.
Define peptide bond.
The bond that connects α-amino acids to each other is called a peptide bond.
Define the term Protein.
Chemically proteins are polyamides which are high molecular weight polymers of the monomer units, i.e., α-amino acids. OR It can also be defined as proteins are the biopolymers of a large number of α-amino acids and they are naturally occurring polymeric nitrogenous organic compounds containing 16% nitrogen and peptide linkages (-CO-NH-)
Define enzymes.
Enzymes are biological catalysts that speed up chemical reactions in living cells without being consumed in the process.
Proteins are complex polyamides formed from amino acids. They are essential for the proper growth and maintenance of the body. They have many peptide (-CO–NH )bonds.
Chemically, proteins are polyamides, which are high molecular weight polymers of the monomer units called \[\alpha\]-amino acids.
Bifunctional organic compounds containing a carboxylic and an amino group either at the same carbon atom or at nearby carbon atoms are called amino acids.
Key Points
- Proteins are polymers of amino acids (polypeptides) in which amino acids are linked by peptide bonds.
- There are 20 types of amino acids, so proteins are heteropolymers (not homopolymers).
- Amino acids are of two types: essential (must be obtained from diet) and non-essential (can be synthesised in the body).
- Proteins are high molecular weight biomolecules (polyamides) made of α-amino acids with a general structure R-CH(NH₂)-COOH.
- Proteins perform various functions such as enzymatic activity, transport, hormonal regulation, immunity, and sensory reception.
- Proteins are of two main types: fibrous proteins (insoluble, structural, e.g., keratin) and globular proteins (soluble, functional, e.g., enzymes, insulin).
- Collagen is the most abundant protein in animals, while RuBisCO is the most abundant enzyme in the biosphere.
Vitamins = organic compounds essential in small amounts for normal growth and functioning
Not synthesised in adequate amounts by the body → must be supplied in the diet.
| Category | Vitamins | Key Feature |
|---|---|---|
| Fat-soluble | A (Retinol), D (Calciferol), E (Tocopherol), K (Phylloquinone) | Stored in the liver and adipose tissue; insoluble in water |
| Water-soluble | B complex (B₁, B₂, B₃, B₅, B₆, B₁₂), C | Transferred to blood frequently; not stored |
Important Questions [8]
- Define peptide bond.
- Which of the Following Vitamins is Water Soluble?
- Vitamin ‘C’ belongs to the class of
- What Are the Sources of Vitamin C and Vitamin K?
- Inflammation of tongue is due to the deficiency of:
- Which Among the Following Vitamins is Also Known as Riboflavin?
- Name Any Two Diseases Caused by Deficiency of Vitamin A
- Which of the Following Vitamins is the Vitamin of Alicyclic Series
