Zoology MCQs for NEET — Practice Questions with Answers

Ultra violet rays can destroy the structure of proteins. UV radiation can cause the breaking of peptide bonds and the formation of cross-links between protein chains, leading to denaturation and loss of function.

Amino acids are amphoteric compounds because they contain both an amino group (-NH2) and a carboxyl group (-COOH). The amino group can act as a base (accepting a proton), and the carboxyl group can act as an acid (donating a proton), making amino acids capable of reacting both as acids and bases.

Each amino acid has a unique side chain, known as the R group, that determines its distinct properties. The –COOH group (carboxyl group) and –NH2 group (amino group) are common to all amino acids, while the peptide bond links amino acids together. Therefore, the specific characteristics of each amino acid are determined by its R group.

Serine and Tyrosine are both amino acids with polar side chains that contain hydroxyl groups (-OH). This similarity in their side chain structures relates them to each other. Valine and Histidine, Glutamate and Proline, Lysine and Leucine have different types of side chains and are not as closely related.

Aspartic acid and lysine are amino acids, and the bond that links amino acids together is called a peptide bond. Peptide bonds are formed through a dehydration synthesis reaction between the carboxyl group of one amino acid and the amino group of another.

A dipeptide is a molecule consisting of two amino acids linked by a single peptide bond. These amino acids can be either similar or dissimilar. Thus, the correct definition of a dipeptide is two similar or dissimilar amino acids attached by a peptide bond.

Polypeptides, which are proteins, are the most diverse macromolecules in cells and they play a crucial role in controlling biochemical properties. Proteins are involved in a wide variety of functions including catalysis of biochemical reactions (enzymes), structural roles, signaling, and transport.

The primary structure of proteins is determined by peptide bonds, which are covalent bonds formed between the amino group of one amino acid and the carboxyl group of another. This sequence of amino acids linked by peptide bonds forms the protein's primary structure.

Proteins are macromolecules, which are large, complex molecules made up of long chains of amino acids. These macromolecules play a variety of crucial roles in biological processes and structures.