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 general chemical equation of photosynthesis, What is the genera...

What is the general chemical equation of photosynthesis? Why doesn't that equation clearly show the real origin of the molecular oxygen liberated? The general equation of photo

Explain back pain, Explain Back pain, arthritis and gout - Effect of Obesit...

Explain Back pain, arthritis and gout - Effect of Obesity? Abdominal obesity increases the risk of back pain because of the extra load on the spinal column. This, in turn, red

What do you mean by polyphagia, Q. What do you mean by Polyphagia? Incr...

Q. What do you mean by Polyphagia? Increased Hunger (Polyphagia): As patient is losing more sugar in the urine, he feels hungry very soon and tends to take more food. It is cal

Which are the phases of the menstrual cycle, Which are the phases of the me...

Which are the phases of the menstrual cycle? The menstrual cycle is separated into two main phases: the follicular (or menstrual) phase and the luteal (or secretory) phase.

When aerobic cells carry out fermentation, Under which conditions do aerobi...

Under which conditions do aerobic cells carry out fermentation? Some cells that as a rule get energy from aerobic cellular respiration can carry out fermentation when oxygen is

What is the mean of crp, CRP is a marker of systemic inflammation. As the r...

CRP is a marker of systemic inflammation. As the role of inflammation in the initiation and progression of atherosclerosis becomes better understood, CRP has gained prominence as a

How poor selection of food causing the underweight, How Poor Selection of F...

How Poor Selection of Food causing the Underweight? Poor Selection of Food: Poor selection of food along with irregular eating habits may be responsible for insufficient food

Loss of biological diversity nowadays, Q. What are the main causes of the l...

Q. What are the main causes of the loss of biological diversity nowadays? The largest dangers to the biological diversity today are the action of humans. The major of them is 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