Cecilia Blikstad: CO2 fixation - Rubisco’s Mechanism, Limitation, and Nature’s Solutions

Chairperson: professor Mikael Widersten

Representative of the Docentship Committee: professor Gunnar Westin

Abstract:

"Biological carbon fixation is the process by which atmospheric carbon dioxide (CO2) is incorporated into biomass. A majority of this occur via the photosynthesis driven Calvin–Benson–Bassham (CBB) cycle in plants, algae, and cyanobacteria. The first step of the CBB cycle is catalysed by ribulose 1,5 bisphosphate carboxylase/oxygenase (Rubisco), the most abundant protein on Earth, which converts CO2 and ribulose 1,5 bisphosphate into two molecules of 3 phosphoglycerate. Despite its central role, Rubisco is relatively slow and fails to discriminate between CO2 and O2, resulting in a competing oxygenation reaction that reduces efficiency. To overcome this, organisms have evolved diverse CO2 concentrating mechanisms that elevate CO2 levels around Rubisco, suppress oxygenation, and enhance overall carbon fixation.

In this lecture, I will introduce CO2 fixation via the CBB cycle, followed by a focus on Rubisco catalysis and the different CO2 concentrating mechanisms that overcome its limitations. The aim is to provide biochemistry students with a clear understanding of the molecular principles underlying CO2 fixation and insight into how this process can be engineered to improve efficiency."

The lecture is an obligatory teaching test for those applying for admittance as docent and it should be possible for students and others with basic academic education in the relevant field to follow it. The lecture lasts 40-45 minutes with subsequent discussion. The lecture will be given in Swedish.

Welcome!