Question

Select the incorrect pair.

• A. 2-carbon compound - Aspartic acid
• B. 3-carbon compound - PGA
• C. 4-carbon compound - Malic acid
• D. 5-carbon compound - RuBP

Answer 1

Answer: (A)

Both malic acid and aspartic acid are $4$-carbon compounds formed in the mesophyll cells during $C_4$ cycle. $PGA$ ($3$-phosphoglyceric acid) is a $3$-carbon compound, which is the first stable product of Calvin cycle ($C_3$ cycle). $RuBP$ (Ribulose- $1,5$-biphosphate) is a $5$-carbon compound, which is the primary acceptor of $C{O}_2$ during $C_3$ cycle.