Question

The first product of $C{O}_2$ fixation in Hatch and Slack cycle in plants is:

• A. formation of bundle sheath cells
• B. formation of oxaloacetate by carboxylation of phosphoenol pyruvate (PEP) in the mesophyll cells
• C. formation of phosphoglyceric acid in mesophyll cells
• D. formation of oxaloacetate by carboxylation of phosphoenol pyruvate (PEP) in bundle sheath cells

Answer 1

Answer: (B)

Hatch and Slack cycle is present in $C_4$ plants in which initial fixation of carbon dioxide $(C{O}_2)$ occurs in mesophyll cells phosphoenol pyruvate (PEP) is the primary acceptor of $C{O}_2$ which combines to $C{O}_2$ form four carbon compounds oxaloacetic acid as a result of carboxylation $PEP+C{O}_2+H_{2}O\underset{\begin{array}{c}Carboxylase\\ Oxalso-aceticacid\end{array}}{\overset{PEP}{\to }}$