Paper 4 · November 2003 · Enzymes
As the ionisable groups of catalase's active site are modified between pH3 and pH7, what specifically is disrupted, allowing the reaction rate to rise?
AThe ionic bonding (or hydrogen bonding) that helps maintain the enzyme's specific shape
BThe disulfide bonds linking two entirely separate catalase polypeptide chains together permanently
CThe covalent peptide bonds that make up the primary structure of the enzyme's backbone
DThe covalent bonds holding together the hydrogen peroxide substrate molecule itself
Explanation
The modification of ionisable groups disrupts the ionic bonding (or hydrogen bonding) that helps maintain the enzyme's specific tertiary shape.
Derived from ZIMSEC Biology 9190/4 Paper 4 (Practical Test), November 2003, Q1