108 public questions tagged with this topic.
Disulfide bonds between cysteine residues help stabilize the tertiary structure of proteins.
Ref: NCERT Class 11 Biology Chapter 9: Biomolecules Enzyme Action and Factors Affecting Enzyme Activity
Hydrogen bonds stabilize the alpha-helix and beta-sheet structures in the secondary structure of proteins.
Ref: NCERT Class 11 Biology Chapter 9: Biomolecules Enzyme Action and Factors Affecting Enzyme Activity
Proteins serve multiple roles, including enzymatic functions, structural support, and transport.
Ref: NCERT Class 11 Biology Chapter 9: Biomolecules Enzymes - Properties Classification and Cofactors
Not all proteins function as enzymes; some have structural, transport, or signaling roles.
Ref: NCERT Class 11 Biology Chapter 9: Biomolecules Enzymes - Properties Classification and Cofactors
Hemoglobin is a conjugated protein that contains a non-protein component, heme.
Ref: NCERT Class 11 Biology Chapter 9: Biomolecules Enzymes - Properties Classification and Cofactors
The secondary structure of proteins includes both alpha-helices and beta-pleated sheets, which are stabilized by hydrogen bonds.
Ref: NCERT Class 11 Biology Chapter 9: Biomolecules Proteins and Polysaccharides - Structure and Functions
Amino acids are the building blocks of proteins. They contain nitrogen, a carboxyl group, and are linked by peptide bonds, not glycosidic bonds.
Ref: NCERT Class 11 Biology Chapter 9: Biomolecules Chemical Analysis and Biomolecules - Amino Acids Lipids
Proteins do not store genetic information; that function belongs to nucleic acids.
Ref: NCERT Class 11 Biology Chapter 9: Biomolecules Chemical Analysis and Biomolecules - Amino Acids Lipids
The quaternary structure refers to the arrangement and interaction of multiple polypeptide chains in a functional protein.
Ref: NCERT Class 11 Biology Chapter 9: Biomolecules Chemical Analysis and Biomolecules - Amino Acids Lipids
A peptide bond forms between the carboxyl group of one amino acid and the amino group of another during protein synthesis.
Ref: NCERT Class 11 Biology Chapter 9: Biomolecules Chemical Analysis and Biomolecules - Amino Acids Lipids
Interpreting absorption and fluorescence fingerprints distinguishes protein composition and tryptophan localization. Protein containing only tyrosine lacks tryptophan, showing λmax near 274 nm, low extinction and emission ~303 nm, designated X. Proteins containing tryptophan exhibit additional 280 nm absorption. Solvent-exposed tryptophan on protein surface contacts water, undergoes full solvent relaxation, emitting near 350-355 nm representing Y. Buried tryptophan within hydrophobic core experiences nonpolar environment restricting relaxation, emitting blue-shifted around 308-335 nm representing Z. Correlating A280, λem and quenching allows assignment of X as only Tyr, Y surface Trp, Z buried Trp.
Ref: NCERT Biology Class XII Principles on Klenow fill-in labeling, Lehninger Chapter 9 DNA cloning techniques, and Molecular Cloning by Sambrook Chapter 10 documenting end-labeling of cohesive termini.
Protease hydrolysis cleaves peptide bonds, fragmenting chain and disrupting hydrogen bonded networks that stabilize helices and sheets. Far-ultraviolet circular dichroism monitors these networks via amide n to pi-star and pi to pi-star bands; loss of distinct minima at 208, 222 or 218 nanometers and appearance of random coil signature near 195 nanometers reflects conformational alteration and unfolding of remaining fragments. Primary sequence composition change alone without structural rearrangement would not alter CD significantly; fluorescence quenching reports side chain environment, disulfide cleavage requires reductant, not protease.
Ref: NCERT Biology Class XII Principles on Klenow fill-in labeling, Lehninger Chapter 9 DNA cloning techniques, and Molecular Cloning by Sambrook Chapter 10 documenting end-labeling of cohesive termini.
