anatomy (Dimorphic chloroplast and Kranz anatomy). Table . : Differences between C and C plants C Plants C Plants . CO fixation takes place in mesophyll cells only .
CO fixation takes place mesophyll and bundle sheath . CO acceptor is RUBP only . PEP in mesophyll and RUBP in bundle sheath cells . First product is 3C- PGA .
First product is 4C- OAA . Kranz anatomy is not present . Kranz anatomy is present . Granum is present in mesophyll cells .
Granum present in mesophyll cells and absent in bundle sheath . Normal Chloroplast . Dimorphic chloroplast . Optimum temperature o to o C .
Optimum temperature o to o C . Fixation of CO at ppm . Fixation of CO even less than ppm . Less efficient due to higher photorespiration .
More efficient due to less photorespiration . RUBP carboxylase enzyme used for fixation . PEP carboxylase and RUBP carboxylase used . ATPs used to synthesize one glucose .
Consumes ATPs to produce one glucose. . Example: Paddy, Wheat, Potato and so on . Example: Sugar cane, Maize, Sorghum , Amaranthus and so on Kranz Anatomy: It is the German term meaning a halo or wreath.
In C4 plants vascular bundles are surrounded by a layer of bundle sheath. Bundle sheath is surrounded by a ring of mesophyll cells. The characteristic feature of C4 plants is the presence of dimorphic chloroplast: Bundle sheath chloroplast: Larger chloroplast, thylakoids not arranged in granum and rich in starch. Mesophyll Chloroplast: Smaller chloroplast, thylakoids arranged in granum and less starch.
(OAA). Subsequently OAA is converted into malic acid like C cycle and gets accumulated in vacuole increasing the acidity. During the day time stomata are closed and malic acid is decarboxylated into pyruvic acid resulting in the decrease of acidity. CO thus formed enters into Calvin Cycle and produces carbohydrates (Figure13.
). Significance of CAM Cycle . It is advantageous for succulent plants to obtain CO