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

Male reproductive disorders due to infections, Male reproductive disorders ...

Male reproductive disorders due to infections Septicemic infections have a greater affinity for vesicular glands than other regions of the reproductive tract viz. prostate, am

Enhancer, The enhancer is the cis-acting nucleotide series to which the tra...

The enhancer is the cis-acting nucleotide series to which the transcription factor(s) bind, and which increases transcription of the gene. It is not part of the promoter; the gener

What is the energy source used in active transport, Q. What is the energy s...

Q. What is the energy source used in active transport through biological membranes? The energy necessary for active transport against the concentration gradient of the transpor

Enumerate the sizes of eukaryotic and prokaryotic cells, Enumerate the Siz...

Enumerate the Sizes and shapes of eukaryotic and prokaryotic cells It is thus possible, due to these similarities, to generalise about the structures and functions of cells. In

Invertibreats, genral charecter and classificatin of porifera

genral charecter and classificatin of porifera

What is signifying by suction force of the plant cell, Q. What is signifyin...

Q. What is signifying by suction force of the plant cell? Does the suction force facilitate or make difficult the entry of water into the cell? The suction force (SF) is the os

Describe about pulmonary respiration, Q. Besides vertebrates two invertebra...

Q. Besides vertebrates two invertebrate phyla contain species that make pulmonary respiration. Which are these phyla? Terrestrial molluscs and the arachnid arthropods are the i

State in brief about the comprehensive neuropsychology, State in brief abou...

State in brief about the Comprehensive neuropsychology Comprehensive neuropsychology testing needs a combination of Context related ideometric and quantitative psychometric app

Define the reaction to food additives, Define the Reaction to Food Additive...

Define the Reaction to Food Additives? Food additives such as preservatives, flavour enhancers and colouring agents have been linked to adverse food reactions. Additives implic

What is the most probable inheritance pattern of a trait, What is the most ...

What is the most probable inheritance pattern of a trait with gaussian proportional distribution of phenotypical forms? If a trait statistically has a normal (bell-shaped curve

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