THE C4 PATHWAY_ PART 02
15.1 هزار بار بازدید -
10 سال پیش
-
For more information:
For more information:
http://www.7activestudio.com
[email protected]
http://www.7activemedical.com/
[email protected]
http://www.sciencetuts.com/
[email protected]
Contact: +91- 9700061777,
040-64501777 / 65864777
7 Active Technology Solutions Pvt.Ltd. is an educational 3D digital content provider for K-12. We also customise the content as per your requirement for companies platform providers colleges etc . 7 Active driving force "The Joy of Happy Learning" -- is what makes difference from other digital content providers. We consider Student needs, Lecturer needs and College needs in designing the 3D & 2D Animated Video Lectures. We are carrying a huge 3D Digital Library ready to use.
Photosynthesis in Higher Plants: THE C4 PATHWAY: Kortschak&Hartt demonstrated that sugarcane leaves are more efficient in absorbing CO2 from the atmosphere. They showed that 4 carbon beta carboxylic acid is formed due to carboxylation. Based on this idea Hatch & Slack worked out an alternate pathway of carbon fixation in sugarcane & it is called as Hatch & Slack cycle or Beta Carboxylation pathway or C4 Cycle or Dicarboxylic acid pathway.It is found in many tropical grasses. Example: Maize, Sorghum, a few dicots - Tribulus, Amaranthus, Euphorbia.The primary acceptor of CO2 in C4 plants is phosphoenol pyruvic acid. It accepts CO2& forms oxalo acetic acid – a first stable product. OAAOxalo Acetic Acid is 4C and dicarboxylase. This reaction is catalysed by PEP carboxylase. This is called Beta Carboxylation. This takes place in mesophyll cells.Oxalo Acetic Acid OAA is reduced to malic acid. The elections necessary for this reduction is supplied by NADP4. The enzyme malic dehydrogenase catalyses the reduction.The carboxylation of PEP & reduction of OAA takes place within the mesophyll cells. Malic acid synthesized within mesophyll cells moves into bundle sheath cells through plasmodesmata.Within the bundle sheath cell malic acid is oxidativelydecarboxylated into pyruvic acid. The enzyme malic enzyme catalyses this decarboxylation. CO2 released in this reaction is accepted by RUBP. CO2 is fixed in C3 cycle. The electrons released in oxidative decarboxylation of malic acid are accepted by NADP+ which is reduced to NADPH.Pyruvic acid synthesized in bundle sheath cell moves into mesophyll cell. In mesophyll cell pyruvic acid is phosphorylated to regenerate PEP. The enzyme pyruvic di kinase catalyses the reaction. Two molecules of ATP are utilized in this reaction. C4 is not a substitute but additional CO2 fixation beneficial for plants. C4 plants are more efficient in carbon fixation than C3 plants because: 1 C4 plants show kranz anatomy is special anatomical features, compartmentation of cell enzymes and metabolites etc.,
http://www.7activestudio.com
[email protected]
http://www.7activemedical.com/
[email protected]
http://www.sciencetuts.com/
[email protected]
Contact: +91- 9700061777,
040-64501777 / 65864777
7 Active Technology Solutions Pvt.Ltd. is an educational 3D digital content provider for K-12. We also customise the content as per your requirement for companies platform providers colleges etc . 7 Active driving force "The Joy of Happy Learning" -- is what makes difference from other digital content providers. We consider Student needs, Lecturer needs and College needs in designing the 3D & 2D Animated Video Lectures. We are carrying a huge 3D Digital Library ready to use.
Photosynthesis in Higher Plants: THE C4 PATHWAY: Kortschak&Hartt demonstrated that sugarcane leaves are more efficient in absorbing CO2 from the atmosphere. They showed that 4 carbon beta carboxylic acid is formed due to carboxylation. Based on this idea Hatch & Slack worked out an alternate pathway of carbon fixation in sugarcane & it is called as Hatch & Slack cycle or Beta Carboxylation pathway or C4 Cycle or Dicarboxylic acid pathway.It is found in many tropical grasses. Example: Maize, Sorghum, a few dicots - Tribulus, Amaranthus, Euphorbia.The primary acceptor of CO2 in C4 plants is phosphoenol pyruvic acid. It accepts CO2& forms oxalo acetic acid – a first stable product. OAAOxalo Acetic Acid is 4C and dicarboxylase. This reaction is catalysed by PEP carboxylase. This is called Beta Carboxylation. This takes place in mesophyll cells.Oxalo Acetic Acid OAA is reduced to malic acid. The elections necessary for this reduction is supplied by NADP4. The enzyme malic dehydrogenase catalyses the reduction.The carboxylation of PEP & reduction of OAA takes place within the mesophyll cells. Malic acid synthesized within mesophyll cells moves into bundle sheath cells through plasmodesmata.Within the bundle sheath cell malic acid is oxidativelydecarboxylated into pyruvic acid. The enzyme malic enzyme catalyses this decarboxylation. CO2 released in this reaction is accepted by RUBP. CO2 is fixed in C3 cycle. The electrons released in oxidative decarboxylation of malic acid are accepted by NADP+ which is reduced to NADPH.Pyruvic acid synthesized in bundle sheath cell moves into mesophyll cell. In mesophyll cell pyruvic acid is phosphorylated to regenerate PEP. The enzyme pyruvic di kinase catalyses the reaction. Two molecules of ATP are utilized in this reaction. C4 is not a substitute but additional CO2 fixation beneficial for plants. C4 plants are more efficient in carbon fixation than C3 plants because: 1 C4 plants show kranz anatomy is special anatomical features, compartmentation of cell enzymes and metabolites etc.,
10 سال پیش
در تاریخ 1393/05/06 منتشر شده
است.
15,122
بـار بازدید شده