Explain alternate photosynthetic pathways, Biology

Assignment Help:

Explain Alternate Photosynthetic Pathways?

An alternate photosynthetic pathway is the C4 pathway, where plants incorporate carbon into four-carbon compounds instead of 3PG. This pathway was found when plants were exposed to 14CO2, a radioactive substance used to trace the steps in biochemical reactions.

In these plants, the CO2 acceptor is phosphoenolpyruvate, or PEP, for short. The four-carbon compounds formed by the C4 pathway reactions are taken up by another type of cell, that releases CO2. The CO2 is taken up by RuBP and used in the Calvin cycle to form sugars used to synthesize and store starches. The reaction catalyzed by the enzyme PEP carboxylase can proceed in very low concentrations of CO2. This represents an adaptation to dry environments, where plants conserve water by keeping the stomata, openings in the leaves where gas exchange occurs, closed as much as possible.

The CAM, or crassulacean acid metabolism, pathway, occurs in cacti and other desert plants. It is similar to the C4 pathway, except that the PEP carboxylase reaction occurs at night and the Calvin cycle predominates in the daytime. During the daytime, the stomata close to preserve water, and the plant uses CO2 trapped in the four-carbon compounds for its metabolism.

 

 


Related Discussions:- Explain alternate photosynthetic pathways

Isonzerization of glucose-6-phosphate, Isonzerization of glucose-6-phosphat...

Isonzerization of glucose-6-phosphate Isonzerization  of  glucose-6-phosphate :  This step  is  catalyzed  by phosphoglucoisomerase to  form  fructose-6-phosphate.

Excretion, The excretory of lizard

The excretory of lizard

Determine the term - origin of life on earth, Based on your reading of the ...

Based on your reading of the article "Origin of Life on Earth" which of the following is a false statement regarding how life developed? A. As proteins are needed for the repli

Surface run-off - causes of water pollution, Surface Run-off - Causes of Wa...

Surface Run-off - Causes of Water Pollution The surface run-off from cultivated lands where inorganic fertilisers, pesticides, insecticides and rich manure are applied and sol

Question, 1)what is plasma membrane? 2)what is multicellularity

1)what is plasma membrane? 2)what is multicellularity

Explain phenotypical characteristics of alleles of a gene, What are few exa...

What are few examples of phenotypical characteristics that present two or more varieties and of phenotypical features that do not vary? In relation to the genes correspondent to th

State the term cercaria, State the term Cercaria? A stage in the life c...

State the term Cercaria? A stage in the life cycle of trematode flukes. Cercaria develops from redia found in intermediate host. This tadpolelike organism is released from inte

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd