Navigation Links
C4 carbon fixation


For other meanings of C4, see C4 (disambiguation)

C4 carbon fixation is a common metabolic pathway found in land plants (C4 plants). They are competitively superior to plants possessing the more common C3 pathway under the conditions of drought, high temperatures and nitrogen limitation. The C4 cycle allows for a spacial separation of carbon fixation from respiration, thus allowing C4 plants to increase concentration of CO2 within their leaves. This increases the amount of photosynthesis and decreases the chances of photorespiration, a harmful process in which organic material and energy is lost from the plant due to high concentrations of oxygen. It is called "C4" because the product, oxaloacetate, contains four carbon atoms. It occurs in the mesophyll of the leaf, specifically in the mesophyll cells and the bundle sheath cells. The chemical equation is:

PEP carboxylase + PEP + CO2 → oxaloacetate

The product is usually converted to malate , a simple organic compound that gives up its CO2 to the Calvin cycle after being shipped off to bundle sheath cells surrounding a nearby vein. After losing the CO2, it becomes pyruvate, and can be phosphorylated into PEP at the cost of a phosphorus group and one ATP. It can then be reused in the above equation.


'"/>


(Date:10/1/2014)... , October 1, 2014 ... the life science field  The life ... and go over the years. Some are shooting ... upconversion is a novel detection technology that has ... Now, finally, this technology is becoming commercially available. ...
(Date:9/30/2014)... nature as something that we enjoy when we visit a ... we think of ourselves as a part of nature? A ... a house? , The answers to these questions reflect ... our speech and in cultural artifacts. , A new Northwestern ... American Indian Center of Chicago and the Menominee tribe of ...
(Date:9/30/2014)... JOLLAJoseph Ecker, a Salk professor and Howard Hughes ... scientist, have been named recipients in the 2014 ... Health (NIH) through the BRAIN (Brain Research through ... neuroscience. The grant, announced September 30, provides more ... scientists over three years. , The BRAIN Initiative, ...
Breaking Biology News(10 mins):First-of-a-kind Solution for Utilizing Photon Upconversion 2The cultural side of science communication 2Salk scientists receive $3 million for BRAIN Initiative grant 2
... will be looking to the food industry to provide products ... lives than previous generations, according to research presented at the ... 78 million baby boomers, defined by the U.S. Census Bureau ... 1964 in the United States. They began reaching the retirement ...
... An expert panel at the Institute of Food ... find simple yet powerful language to tell consumers about ... Phytonutrients are plant-based components that are thought to ... are typically found in fruits, vegetables, grains, legumes, nuts ...
... Mass. The U.S. National Research Council this week ... in 60 countries who took part in the International ... years to offer a benchmark for environmental conditions and ... of Massachusetts Amherst geosciences researcher and expert in the ...
Cached Biology News:NRC authors brief federal agencies on the state of polar regions 2NRC authors brief federal agencies on the state of polar regions 3
Other biology definitionOther Tags