Make Entry -- Become an Editor -- Most Popular: (10, 25, 50, 75, 100)

   Help

Rubisco

Rubisco, a critical element in the process of photosynthesis, is short for "ribulose-1,5-biphosphate carboxylase/oxygenase”. It is an enzyme that catalyzes the first major step of carbon fixation in the creation of sucrose and similar molecules. This is the most common chemical reaction by which carbon is fixed into organic molecules. Rubisco is probably the most abundant protein in leaves, and may be the most abundant on Earth. Genetic engineers are trying to make the functioning of plant rubisco more efficient; a line of, say, corn plants with hyperefficient rubisco could make high-quality ethanol (a renewable energy source) in larger volumes than ordinary corn, and would remove more carbon dioxide from the atmosphere as well.

Rubisco is slow compared to many enzymes; it can fix only a few carbon dioxide molecules per second; compare this to enzymes that can catalyze thousands of chemical reactions per second. When light is not an issue, Rubisco is the most rate-limiting enzyme of the Calvin cycle, the first step in photosynthesis.

Genetic engineers are trying to maximize the expression of the genes for Rubisco by moving them to different organisms, doubling the number of genes with Rubisco coding, and altering them to increase selectivity for high carbon dioxide removal.

Magnesium ions are critical for proper functioning of rubisco.

Web Resources On Rubisco

Ribulose-1,5-bisphosphate carboxylase
The Calvin-Benson Cycle

Book Resources On Rubisco

The photosynthetic cycle by Melvin Calvin
Molecular Mechanisms of Photosynthesis by Robert E. Blankenship

Site Maps: Most Recent | Clusters | Browse
New: Graduate Student Job Opportunity