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...

An artistic depiction of a human embryo
Growth and Development of a Human Baby

Upon fertilization, a zygote forms and develops into an embryo. This tutorial elaborates on the growth and development f..

genes controlling growth and development
Control of Growth & Development

Control of Growth & Development tutorials look at how the genetic makeup determines the biological processes on a da..

takahē
Takahē (Porphyrio hochstetteri)

Meet the colorful takahē, an extremely rare flightless bird. Find out more about its unique features and why they matte..

Early Mammals on Earth
Early Mammals on Earth

The Earth's ecosphere was rapidly changing and throwing up a wide range of ecological niches that new adaptive organisms..

Regulation of Biological Systems
Regulation of Biological Systems

Regulation of Biological Systems tutorials are focused on the modulation of biological systems from cell to population l..

Digestion and Absorption of Food
Digestion and Absorption of Food

The gastrointestinal system breaks down particles of ingested food into molecular forms by enzymes through digestion and..