Question

Hatch and Slack who discovered alternate method of carbon fixation were from

• A. England
• B. Australia
• C. America
• D. New Zealand

Answer 1

Answer: (B)

Australia

Hatch and Slack who discovered an alternate method of carbon fixation were from Australia. Hatch-Slack pathway is a cyclic process. It occurs in chloroplasts. It is also known as $C_4$ pathway because it is found in $C_4$ plants. Carbon dioxide fixation is done in this pathway. The primary $C{O}_2$ acceptor is a three-carbon molecule phosphoenol pyruvate (PEP) and it is present in mesophyll cells. The enzyme that catalyzes this $C{O}_2$ fixation is PEP carboxylase or PEPcase. The mesophyll cells of $C_4$ plants lack the enzyme RuBisCO. The 4-carbon oxaloacetic acid (OAA) is formed in the mesophyll cells which is further converted into the malic acid or aspartic acid and then transported into bundle sheath cells. In the bundle sheath cells, these $C_4$ acids are broken down to release $C{O}_2$ and a three-carbon molecule.