Practice questions covering proteins, amino acids, their classification as essential or non-essential, and how their structure relates to function.
Glutamic acid has two carboxyl groups: one in the main chain (-COOH) and one in the side chain (-CH₂-CH₂-COOH).
Ref: NCERT Class 12 Chemistry > Chapter 14: Biomolecules > Topic: Proteins - Amino Acids - Essential, Non-Essential and Structure
Cysteine forms disulfide bridges (-S-S-) via oxidation of its sulfhydryl groups, stabilizing protein structure.
Ref: NCERT Class 12 Chemistry > Chapter 14: Biomolecules > Topic: Proteins - Amino Acids - Essential, Non-Essential and Structure
Phenylalanine has a side chain with a benzene ring (-CH₂-C₆H₅), making it aromatic.
Ref: NCERT Class 12 Chemistry > Chapter 14: Biomolecules > Topic: Proteins - Amino Acids - Essential, Non-Essential and Structure
Tyrosine, with its aromatic phenol side chain, can contribute to protein coloration due to its light-absorbing properties.
Ref: NCERT Class 12 Chemistry > Chapter 14: Biomolecules > Topic: Proteins - Amino Acids - Essential, Non-Essential and Structure
Histidine’s imidazole side chain has a pKa near physiological pH (~6.0), allowing it to act as a buffer.
Ref: NCERT Class 12 Chemistry > Chapter 14: Biomolecules > Topic: Proteins - Amino Acids - Essential, Non-Essential and Structure
Tryptophan has an indole ring (a benzene ring fused to a pyrrole ring) in its side chain, making it aromatic.
Ref: NCERT Class 12 Chemistry > Chapter 14: Biomolecules > Topic: Proteins - Amino Acids - Essential, Non-Essential and Structure
Glycine lacks a chiral carbon because its side chain is a hydrogen atom, making Cα symmetrical.
Ref: NCERT Class 12 Chemistry > Chapter 14: Biomolecules > Topic: Proteins - Amino Acids - Essential, Non-Essential and Structure
Threonine has a hydroxyl group (-OH) in its side chain (-CH(OH)-CH₃), enabling hydrogen bonding.
Ref: NCERT Class 12 Chemistry > Chapter 14: Biomolecules > Topic: Proteins - Amino Acids - Essential, Non-Essential and Structure
Glycine has the simplest structure with a hydrogen atom as its side chain (-H).
Ref: NCERT Class 12 Chemistry > Chapter 14: Biomolecules > Topic: Proteins - Amino Acids - Essential, Non-Essential and Structure
Non-essential amino acids can be synthesized by the body. Serine is one such amino acid.
Ref: NCERT Class 12 Chemistry > Chapter 14: Biomolecules > Topic: Proteins - Amino Acids - Essential, Non-Essential and Structure
The primary structure of a protein is the sequence of amino acids linked by peptide bonds between carboxyl and amino groups.
Ref: NCERT Class 12 Chemistry > Chapter 14: Biomolecules > Topic: Proteins - Amino Acids - Essential, Non-Essential and Structure
Aspartic acid has an acidic side chain (-CH₂-COOH), capable of donating protons.
Ref: NCERT Class 12 Chemistry > Chapter 14: Biomolecules > Topic: Proteins - Amino Acids - Essential, Non-Essential and Structure
