Question

Write three differences between $C_3$ and $C_4$ cycles.

Answer 1

$C_3$ Cycle	$C_4$ Cycle
1) The primary acceptor of $C{O}_2$ is a $5$-carbon compound- RuBP.	The primary acceptor of $C{O}_2$ is a 3 carbon compound PEP.
2) The first stable compound is a $3$-carbon compound $3$-PGA, phosphoglyceric acid.	The first stable compound is a $4$-carbon compound oxaloacetate.
3) Optimum temperature for this cycle is ${10}^o-{25}^o$C.	Optimum temperature for this cycle is ${30}^o-{45}^o$C.
4) In $C_3$ plants, $18$ ATP and $12$ NADPH are required.	In $C_3$ plants, $18$ ATP and $12$ NADPH are required.
5) Less energy required.	More energy required.