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

Define the dietary management for underweight, Define the Dietary Managemen...

Define the Dietary Management for Underweight? We just read about the etiological factors that may lead to undernutritioin and weight loss. Whatever may be the cause, all under

Define nutritional requirements of fats and oils, Define Nutritional Requir...

Define Nutritional Requirements of Fats and Oils? As with the other macronutrients, we do compute requirements of visible fats too for all age groups and give guidelines for se

Explain phylum ascomycetes, Phylum Ascomycetes 1) Sexual reproduction i...

Phylum Ascomycetes 1) Sexual reproduction is by conjugation and is followed by the formation of ascospores inside a sac called ascus. 2) The asci may be grouped together to

State the term - antecedent and consequence control, Antecedent and consequ...

Antecedent and consequence control Therapy and consultation cannot be effective unless the behaviours to be changed are understood within a particular context. The process of u

Planning for evaluation, PLANNING FOR EVALUATION: The need for clearly...

PLANNING FOR EVALUATION: The need for clearly defined objectives for the evaluation process, analysis of  the need for it, systematic measures for accomplishing its purpose an

What is the basic need for bone grafting, What is the basic need for bone g...

What is the basic need for bone grafting The basic need for bone grafting includes situations like: 1. Implant site development- when the quantity of bone is deficient to s

Proteins, .please i need someone who can finish the assignment today , and ...

.please i need someone who can finish the assignment today , and one reliable who will not cancel the order at last time.in regards to the assignment, the are two pages of question

Method to estimate phytochrome, Method to Estimate Phytochrome Since t...

Method to Estimate Phytochrome Since there is no chemical test, the only method available to test and estimate phytochrome is the spectrophotometric method. Firstly, the diffe

Human impact on the environmetn, what are the two main pollutants that cont...

what are the two main pollutants that contribute to acidic rain?

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