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

How do malign neoplasias appear, Q. How do malign neoplasias appear? Th...

Q. How do malign neoplasias appear? The Neoplasias appear due to DNA mutations in genes that regulate the cellular proliferation thus making the cell lose its capacity to contr

Need for microbiological analysis of environment sample, Explain Need For M...

Explain Need For Microbiological Analysis of Environment Samples? Once the food is harvested, it passes through various operating steps before reaching the consumer. These step

Why o-h bond is a polar covalent bond, Describe how electro negativity can ...

Describe how electro negativity can explain why a C-H bond is a no polar covalent bond, but a O-H bond is a polar covalent bond.

Aquatic ecosystem - types of ecosystem, Aquatic Ecosystem - Types of Ecosys...

Aquatic Ecosystem - Types of Ecosystem Global waters cover about three quarters of the earth's surface either as fresh water where salt content is less than 0.5 per cent or as

What do you understand by amphid, What do you Understand by Amphid? Uni...

What do you Understand by Amphid? Unique to the nematodes, these paired sensory structures are located on the sides of the head. An external pore leads to an inner chamber and

What is the process of evolution, Why acquired traits are not directly rela...

Why acquired traits are not directly related to the process of evolution? As acquired traits are not genetically determined, they cannot be passed on to offspring. Therefore,

What are the main functions of the cytoskeleton, Q. What are the main funct...

Q. What are the main functions of the cytoskeleton? As the name indicates, the cytoskeleton is accountable for the support of the normal shape of the cell it also acts as a fac

Explain research dietitians, Explain Research dietitians Research diet...

Explain Research dietitians Research dietitians work in the field of normal or therapeutic nutrition Research dietitians seek ways to improve the nutrition of both  healthy

What do you mean by sex ratio, What do you mean by sex ratio? Sex Rati...

What do you mean by sex ratio? Sex Ratio is defined as "the number of females per 1000 males". Sex ratio is an important social indicator to measure the extent of prevailing e

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