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

What is the function of cholecystokin, How is it produced and what is the f...

How is it produced and what is the function of cholecystokin in the digestive process? The fat level of the chyme detect in the duodenum stimulates the secretion of cholecystok

Explain the steps of converting food into energy, Explain the steps of conv...

Explain the steps of converting food into energy. There are four steps to convert food into energy: a) Ingestion, mastication and swallowing : Ingestion or taking in of food

Determination of proteins and amino acid content in foods, Define Methods o...

Define Methods of Determination of Proteins and Amino Acid Content in Foods? The methods for protein quality evaluation are grouped under the following headings: I) Analytic

What was the case of phineas gage, What was the case of Phineas Gage S...

What was the case of Phineas Gage Some Procedures are not used experimentally on humans, but sometimes brain tissue is ablated for medical reasons such as the excision of tumo

Classify biomaterials and list some examples, Q. Classify biomaterials and ...

Q. Classify biomaterials and list some examples? Biologic classification is based on tissue response and systemic toxicity effects of the implant and is divided into three clas

Determine fragment of nucleic acid has a nucleotide sequence, If a fragment...

If a fragment of nucleic acid has a nucleotide sequence TAC can one assert that it is a codon or an anticodon? A nucleic acid having a TAC sequence surely is not tRNA, it is DN

How formation of gametes begin in women, In which period of life does the f...

In which period of life does the formation of gametes begin in women? The meiosis that forms female gametes begins in the cells of the ovarian follicles before birth. After the

Monosaccharides, discuss the stereo isomerism of monosaccharides

discuss the stereo isomerism of monosaccharides

Explain bryophytes and tracheophytes, What is the difference between bryoph...

What is the difference between bryophytes and tracheophytes? Bryophytes are nonvascular plants (mosses, hornworts, liverworts), i.e., they do not have a conductive system for t

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