Govt Exams
Molecular chaperones like Hsp70 and Hsp90 help nascent proteins fold into their correct three-dimensional structure and prevent inappropriate aggregation, essential for cellular proteostasis.
Aldolase requires a Zn²⁺ cofactor as part of its active site, which is crucial for substrate binding and catalysis in aldol condensation reactions.
In non-competitive inhibition, both Km and Vmax are affected proportionally. On a Lineweaver-Burk plot (1/v vs 1/[S]), this results in lines with different slopes that intersect on the y-axis.
Leucine is a nonpolar, hydrophobic amino acid that tends to cluster in the protein interior away from the aqueous environment, while polar and charged residues prefer the surface.
An alpha-helix makes 3.6 residues per turn. Each C=O of residue n forms a hydrogen bond with the N-H of residue n+4, resulting in approximately 4 hydrogen bonds per turn.
Enzyme specificity arises from the precise three-dimensional arrangement of amino acid residues in the active site, which determines substrate recognition and binding through complementary fit.
In competitive inhibition, the inhibitor competes with substrate for the active site. The apparent Km increases (appears to require more substrate to reach Vmax), but true Vmax remains unchanged because the inhibitor can be outcompeted at high substrate concentrations.
Trypsin is a serine protease that specifically recognizes and cleaves peptide bonds on the C-terminal side of positively charged amino acids (Lys and Arg).
Allosteric enzymes have regulatory sites distinct from active sites and show cooperativity, resulting in sigmoidal kinetics rather than hyperbolic kinetics seen in simple enzymes.
Ca²⁺ is required for enzymatic activity and is not consumed in the reaction, making it a cofactor. Many proteases require metal ions as structural or catalytic cofactors.