Ribulose Bisphosphate
Ribulose Bisphosphate - Related Videos
07:26
Single-molecule Super-resolution Imaging of Phosphatidylinositol 4,5-bisphosphate in the Plasma Membrane with Novel Fluorescent Probes
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Cited by 9 •
2016
PI(4,5)P2 regulates various cellular functions, but its nanoscale organization in the cell plasma membrane is poorly understood. By labeling PI(4,5)P2 with a dual-color fluorescent probe fused to the Pleckstrin Homology domain, we describe a novel approach to study the PI(4,5)P2 spatial distribution in the plasma membrane at the nanometer scale.
14:38
Establishment of Microbial Eukaryotic Enrichment Cultures from a Chemically Stratified Antarctic Lake and Assessment of Carbon Fixation Potential
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Cited by 5 •
2012
Microbial eukaryotes are both a source of photosynthetically-derived carbon and top predatory species in permanently ice-covered Antarctic lakes. This report describes an enrichment culture approach to isolate metabolically versatile microbial eukaryotes from the Antarctic lake, Lake Bonney, and assesses inorganic carbon fixation potential using a radioisotope assay for Ribulose-1,5-bisphophate carboxylase oxygenase (RubisCO) activity.
10:58
PIP-on-a-chip: A Label-free Study of Protein-phosphoinositide Interactions
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Cited by 7 •
2017
Here we present a supported lipid bilayer in the context of a microfluidic platform to study protein-phosphoinositide interactions using a label-free method based on pH modulation.
01:20
Energy-requiring Steps of Glycolysis
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2019
Glucose is the source of nearly all energy used by organisms. The first step of converting glucose into usable energy is called glycolysis. Glycolysis occurs in the cytosol of the cell over two phases: an energy-requiring phase and an energy-releasing phase. Over the first three steps, glucose is converted into different forms and attached to two phosphate groups donated by two ATP molecules, resulting in an unstable sugar. In the next two stages, the unstable sugar splits into two sugar...
10:52
Radiolabeling and Quantification of Cellular Levels of Phosphoinositides by High Performance Liquid Chromatography-coupled Flow Scintillation
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Cited by 21 •
2016
Phosphoinositides are signaling lipids whose relative abundance rapidly changes in response to various stimuli. This article describes a method to measure the abundance of phosphoinositides by metabolically labeling cells with 3H-myo-inositol, followed by extraction and deacylation. Extracted glycero-inositides are then separated by high-performance liquid chromatography and quantified by flow scintillation.
FAQs
Rubisco catalyzes the addition of carbon dioxide to ribulose bisphosphate, briefly creating a six-carbon intermediate. That intermediate is unstable and immediately divides into two molecules of 3-phosphoglycerate. This sequence converts inorganic carbon into a defined compound that can enter the Calvin cycle and contribute to later carbohydrate production.
Rubisco can react with oxygen as well as carbon dioxide, so RuBP becomes involved in photorespiration when oxygen is used. This alternative reaction diverts the chemistry away from carbon assimilation and helps explain why Rubisco activity can reduce photosynthetic efficiency under conditions where photorespiration occurs.
ATP supplies energy for the reactions that restore ribulose bisphosphate after carbon fixation. Regeneration is essential because the molecule must be available again for another Rubisco-catalyzed reaction. By linking energy use to substrate renewal, the Calvin cycle can continue processing carbon dioxide rather than stopping after a single fixation event.
The unstable intermediate formed after carbon dioxide is added does not persist as a final cycle product. Its rapid division produces two three-carbon molecules of 3-phosphoglycerate, connecting the initial fixation step with the subsequent reactions of the Calvin cycle. This conversion makes newly incorporated carbon available for the pathway that supports carbohydrate production.
Because RuBP is the substrate at the point where Rubisco can direct carbon through carbon fixation or photorespiration, its chemistry provides a way to examine competing outcomes in photosynthesis. Studying this role helps researchers connect Rubisco activity with the efficiency of carbon assimilation and with the broader functioning of plant metabolism.
Its repeated use and regeneration connect several aspects of plant biology: carbon dioxide incorporation, ATP-dependent cycle maintenance, carbohydrate production, and photorespiration. Consequently, RuBP is relevant not only to the Calvin cycle but also to interpreting how plants manage carbon assimilation and why Rubisco chemistry affects overall photosynthetic performance.