Govt Exams
Tertiary structure requires secondary structure elements. Secondary structures (α-helix, β-sheet) fold into tertiary structure; one cannot exist without the other.
Apparent Km = Km(1 + [I]/Ki) = 2(1 + 1/0.5) = 2(1 + 2) = 6 mM. Competitive inhibition increases apparent Km without changing Vmax.
Serine proteases (like trypsin, chymotrypsin) form an acyl-enzyme intermediate through a nucleophilic attack by the active site serine residue.
GAA codes for Glutamic acid (Glu), GUA codes for Valine (Val). This is a non-conservative substitution of a charged to hydrophobic residue.
Cooperative binding (positive cooperativity) occurs when binding of one substrate molecule increases affinity for subsequent molecules, a classic example of allosteric regulation as seen in hemoglobin.
Lipase catalyzes the hydrolysis of ester bonds in lipids. Amylase acts on carbohydrates, protease on proteins, and nuclease on nucleic acids.
Extreme pH causes ionization of amino acid side chains and disruption of protein structure, leading to denaturation and loss of enzymatic activity.
Quaternary structure involves interactions between different polypeptide chains, not covalent peptide bonds. Only non-covalent interactions maintain quaternary structure.
Leucine, Isoleucine, and Valine are branched-chain hydrophobic amino acids typically buried in the interior of folded proteins.
Peptide bond formation is part of protein synthesis and structure, not denaturation. Denaturation involves disruption of secondary and tertiary structures.