Dictionary > Carboxysome

Carboxysome

Carboxysome is a protein-shell micro-compartment inside bacterial cell and is involved chiefly in carbon fixation. It is a cytoplasmic proteinaceous structure in the cytosol of bacteria such as Cyanobacteria and other CO2-fixing bacteria. It is made up of polyhedral protein shells of 80-140 nm in diameter. It contains enzymes (e.g. ribulose-1,5-biphosphate carboxylase/oxygenase or RubisCO) involved in carbon fixation. Its function is to ensure that there is an adequate concentration of carbon dioxide (CO2) for fixation. It concentrates carbon dioxide inside through co-localized carbonic anhydrase activity that produces CO2 from bicarbonate. The protein shell of the carboxysome prevents the escape of CO2. Having sufficient CO2 near RuBisCO inside the carboxysome warrants carbon fixation and prevents too much photorespiration. Apart from carboxysome, other organellar-like structures in prokaryotes are chlorosome and magnetosome.

See also

References

  1. 4.6C: Carboxysomes. (2019, June 5). Retrieved from Biology LibreTexts website: https://bio.libretexts.org/Bookshelves/Microbiology/Book%3A_Microbiology_(Boundless)/4%3A_Cell_Structure_of_Bacteria%2C_Archaea%2C_and_Eukaryotes/4.6%3A_Specialized_Internal_Structures_of_Prokaryotes/4.6C%3A_Carboxysomes

© Biology Online. Content provided and moderated by Biology Online Editors



You will also like...

Evolution of Life - Ancient Earth
Evolution of Life – Ancient Earth

Autotrophs flourished, absorbing carbon and light. Soon after, primitive life forms that could assimilate oxygen thrived..

green plant cells
Plant Cells vs. Animal Cells

Plant cells have plastids essential in photosynthesis. They also have an additional layer called cell wall on their cell..

Adaptation Tutorial
Adaptation Tutorial

Adaptation, in biology and ecology, refers to the process or trait through which organisms or the populations in a habit..

Chromosomes X and Y and Sex Determination
Chromosomes X and Y and Sex Determination

This tutorial looks at sex determination via the sex chromosomes, X and Y. Read it to get more info on X and Y chromosom..

Direct and indirect physiologic effects of growth hormone
Animal Growth Hormones

Hormones are produced in the endocrine glands of animals. The pituitary gland and hypothalamus are the most impor..

New Zealand Fauna
New Zealand’s Unique Fauna

Meet some of New Zealand's unique fauna, including endemic insects, frogs, reptiles, birds, and mammals, and investigate..

Related Articles...

No related articles found

See all Related Topics