Question

Enzymes that catalyse removal of groups from substrates by mechanisms other than hydrolysis, and addition of groups to double bonds, are called

• A. Ligase
• B. Lyase
• C. Hydrolase
• D. Dehydrogenase

Answer 1

Answer: (B)

Lyase

Lyases enzymes catalyse the breakage of specific covalent bonds and removal of group with out hydrolysis producing double bonds or removal of double bonds by adding group,e.g., histidine decarboxylase that splits $C-C$ bond of histidine,forming $C{O}_2$ and histamine.

$\stackrel{X}{\stackrel{|}{C}}-\stackrel{Y}{\stackrel{|}{C}}\stackrel{lyase}{\to }X-Y+C=C$