Related Experiment Video
Updated: Jul 7, 2026

Isolating and Incorporating Light-Harvesting Antennas from Diatom Cyclotella Meneghiniana in Liposomes with Thylakoid Lipids
Published on: August 28, 2018
Bicarbonate transport and extracellular carbonic anhydrase in marine diatoms
Cheryl L Martin1, Philippe D Tortell
1Department of Botany, University of British Columbia, 6270 University Blvd., Vancouver, BC, Canada V6T 1Z4.
Abstract:
In this article, we present new laboratory results examining the relative importance of HCO(-)(3) transport and extracellular carbonic anhydrase (eCA) in 17 marine diatom species. We observed significant variability in both HCO(-)(3) transport and eCA expression across a range of diatom species with different cell morphologies. All species we examined took up HCO(-)(3) through a direct transport mechanism, with the fraction of HCO(-)(3) transport ranging from 40 to 95% of total C uptake. eCA expression also varied significantly, with catalytic enhancement factors ranging approximately 10-fold among species. There was a significant positive correlation between HCO(-)(3) transport and eCA expression among the test species. However, neither HCO(-)(3) transport nor eCA expression was significantly correlated to cell growth rates or surface area to volume ratios. We did observe weak positive trends between the ratio of C demand:supply and HCO(-)(3) utilization/eCA expression, but these were not statistically significant. We are thus unable to provide a mechanistic explanation for the apparent variability in HCO(-)(3) transport and eCA expression in marine diatoms. This variability may, nonetheless, have important implications for the physiological ecology of oceanic diatoms.
Related Concept Videos
Carbon Dioxide Transport in the Blood
Forms of CO2 Transport
1. Dissolved in plasma: A small percentage (7-10%) of CO2 is transported and dissolved directly in the plasma.
2. Carbaminohemoglobin: Just over 20% of CO2 is chemically bound to...
Bicarbonate-Carbonic Acid Buffer
Carbon-dioxide Fixation
Roles of Electrolytes: Chloride and Bicarbonate
Conditions such as hypochloremia can arise from insufficient chloride reabsorption by the kidneys, often compounded by extended bouts of diarrhea, vomiting, or...
The Calvin Benson Cycle
The Carbon Cycle

