alleryThe C4 pathway (Hatch-Slack) uses which enzyme for the initial CO2 fixation?
ARuBisCO (in mesophyll cells)
BRuBisCO (in bundle-sheath cells)
CPEP carboxylase (in mesophyll cells)
DATP synthase (in mesophyll cells)
Answer & Solution
Correct answer: C. PEP carboxylase (in mesophyll cells)
In C4, PEP carboxylase in MESOPHYLL cells fixes CO2 into oxaloacetate (4C).
Transported to BUNDLE SHEATH cells where RuBisCO then does the Calvin cycle.
PEP carboxylase has higher affinity for CO2; less photorespiration.
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