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

Why do preserved foods not spoil, Why do preserved foods not spoil? Pla...

Why do preserved foods not spoil? Plant and animal cells must stay in an isotonic, or neutral, solution to survive. When salt or sugar is added, more of the cells wither and di

Proteins, what is proteins?properties of protein

what is proteins?properties of protein

What is primary structure of a protein, Q. What is primary structure of a p...

Q. What is primary structure of a protein? What is the significance of the primary structure? The primary protein structure is the linear sequence of amino acids that outline t

What is chroma in soil, What is Chroma in soil Chroma is the relative p...

What is Chroma in soil Chroma is the relative purity or strength of the spectral colour and its numerical value extend from (/0) for neutral colours to (/8) for the strongest e

Mechanical isolation, In certain instances differences in the morphology of...

In certain instances differences in the morphology of genitalia between species make it impossible for normal mating to occur, and sympatric species tend to remain isolated. When t

Define r and k strategists, Define r and K Strategists? Ecologists have...

Define r and K Strategists? Ecologists have identified two major types of reproductive strategies among species. Characteristic patterns can be seen among species relating the

The signals for parturition originate from, The signals for parturition ori...

The signals for parturition originate from: 1. placenta only 2. placenta as well as fully developed foetus 3. oxytocin released from maternal pituitary 4. fully develop

Gastrointestinal tract function , Gastrointestinal Tract Function: As...

Gastrointestinal Tract Function: As a result of burn  injury acute gastric dilation occurs, creating abdominal distention and  regurgitations. Malabsorption occurs secondary

Criteria of essentiality, Criteria of Essentiality Amon and Stout as e...

Criteria of Essentiality Amon and Stout as early as 1939, suggested certain criteria that an element must fulfil in order to be classified as essential. These criteria are lis

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