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

Endocrine glands of an insect, ENDOCRINE GLANDS OF AN INSECT - The endo...

ENDOCRINE GLANDS OF AN INSECT - The endocrine glands of cockroach are as follows. 1.       Intercerebral gland cells. These cells lie in the brain. They secrete brain horm

What is cholesterol, Q. What is Cholesterol? In its free, unesterified ...

Q. What is Cholesterol? In its free, unesterified form cholesterol is a major component (together with phospolipid) of cell membranes. Its presence helps to stabilize membrane

How many larvae per treatment, A study is made to verify the effects of pes...

A study is made to verify the effects of pesticide exposure on pupal weight of butterflies. In a pilot study, 5 randomly selected larvae are raised on plants exposed to the pestici

Define the dietary sources and chemical forms, Define the Dietary Sources a...

Define the Dietary Sources and Chemical Forms? Isoflavones and coumestans are the most common compounds. Soybeans and soyfoods are the most important sources, containing approx

Photosynthesis, test to prove that carbondioxide is needed for photosynthes...

test to prove that carbondioxide is needed for photosynthesis to take place

Observation of the anatomical structures, This assignment was done, sent in...

This assignment was done, sent in marked then sent back to me to be resubmitted. Comments were grammar & structure to be reviewed so could you please proof read & make it more acad

Psychological aspects of tooth loss, The psychological effects of total ede...

The psychological effects of total edentulism are complex and varied, and range from very minimal to a state of neuroticism. Although complete dentures are able to satisfy the esth

Zoonoses disease-ehrlichiosis, Ehrlichiosis The disease is caused by a ric...

Ehrlichiosis The disease is caused by a rickettisia, called Ehrlichia canis. Dogs and man are the reservoir hosts. The infection is transmitted through bite of infected tick, Rhip

Nutrition occurs in protozoans, Nutrition occurs in Protozoans All typ...

Nutrition occurs in Protozoans All types of nutrition occur in Protozoa. Some protozoans synthesize their own food from inorganic precursors (carbon dioxide, nitrates or ammon

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