Question
Biology Question on Photosynthesis in higher plants
In C4 plants, CO2 combines with
A
phosphoenol pyruvate
B
phosphoglyceraldehyde
C
phosphoglyceric acid
D
ribulose diphosphate.
Answer
phosphoenol pyruvate
Explanation
Solution
C4 pathway was first reported in members of family Gramineae (grasses) like sugarcane, maize, sorghum, etc. These C4 plants have a characteristic leaf anatomy called Kranz anatomy. So in chloroplasts of mesophyll cells - PEPCo (PEP carboylase) is the key enzyme used to fix CO2 in C4 plants Oxaloacetic acid is a 4-C compound and is the first stable product so this pathway is known as C4 cycle.