RuBP full form in biology

By: Prof. Dr. Fazal Rehman | Last updated: February 3, 2024

RuBP full form in biology:

 

  • Full form of RuBP in biology is Ribulose-1,5-bisphosphate.
  • It is a five-carbon sugar molecule that plays an important role in the first step of the Calvin cycle.
  • The regeneration of RuBP is essential for the continuous functioning of the Calvin cycle during the process of photosynthesis.
PropertyDescription
Full Form·        Ribulose-1,5-bisphosphate
Discovery and naming·        RuBP was originally discovered by Andrew Benson in 1951 while working in the lab of Melvin Calvin at UC Berkeley.

·        At early times, the molecule was known as ribulose diphosphate (RuDP) but the prefix di- was changed to bis- to emphasize the nonadjacency of the two phosphate groups.

Chemical Formula·        C5H12O11P2
Role in Photosynthesis·        Key molecule in the Calvin cycle of photosynthesis.

·        Acts as a CO2 acceptor during carbon fixation.

Carbon Fixation·        Combines with CO2 in the Calvin cycle to form a six-carbon compound
Enzyme·        RUBP reacts with CO2 in the presence of the enzyme RUBISCO
Regeneration·        RUBP is continuously regenerated through a series of reactions within the Calvin cycle to maintain the cycle’s functionality.
Importance·        Essential for the synthesis of glucose and other carbohydrates during photosynthesis.
Presence·        Present in all photosynthetic organisms where photosynthesis occurs such as

·        plants

·        algae

·        cyanobacteria

Location in plants·        Found in the stroma of chloroplasts, which is a cellular organelle responsible for photosynthesis.
Location in Cyanobacteria·        Found in the stroma of thylakoids
Recycling of ATP and NADPH·        It participates in the regeneration phase of the Calvin cycle that requires ATP and NADPH which are generated during the light-dependent reactions of photosynthesis.
Carbon Storage·        RUBP is involved in storing carbon from atmospheric carbon dioxide into organic compounds.

·        It contributes to biomass production in plants.

Regulation·        The availability of RUBP and its efficient regeneration can influence the rate of photosynthesis.
Interaction with RuBisCO·        RUBP binds to the active site of RuBisCO, providing the substrate for carbon dioxide fixation and subsequent carbon reduction.

 

A Comparison between RuBP and Rubisco

Aspect         RuBP Rubisco
Full form·        Ribulose-1,5-bisphosphate·        Ribulose-1,5-bisphosphate    carboxylase/oxygenase
Time of Discovery·        Around the same time as the discovery of Rubisco, as part of the research efforts on the Calvin cycle.·        1940s
Location·        Present in the stroma of chloroplasts, where the Calvin cycle takes place.·        Present in the stroma of chloroplasts, primarily in the mesophyll cells of leaves.
Type of Molecule·        RuBP is a 5-carbon sugar phosphate.·        Rubisco is an enzyme, specifically a carboxylase/oxygenase enzyme.
Chemical Formula·        C5H12O11P2·        Don’t have any formula because it is an enzyme
Function·        A 5-carbon sugar molecule that acts as the starting point for carbon fixation in the Calvin cycle.·        It catalyzes the addition of CO2 to RuBP thus initiates the Calvin cycle and carbon fixation.

·        It is a key enzyme in photosynthesis.

Role in Photosynthesis·        Acts as the primary acceptor of CO2 during carbon fixation in the Calvin cycle.·        Catalyzes the carboxylation and oxygenation of RuBP, leading to the formation of two molecules of 3-phosphoglycerate (3-PGA).
Function during Carbon Fixation·        Acts as a receptor for CO2 molecules and is essential for their attachment to organic molecules.·        Catalyzes the carboxylation reaction, combining CO2 with RuBP to form a 6-carbon intermediate that quickly breaks down into two molecules of 3-PGA.
Specificity·        High specificity for CO2 molecules, which it prefers to bind during carbon fixation.·        Not highly specific and it can also bind to oxygen molecules, leading to a wasteful process called photorespiration. This reduces its efficiency.
Efficiency·        Efficient in capturing and fixing CO2 molecules during the Calvin cycle.·        Rubisco has a relatively low catalytic efficiency and is considered one of the slowest enzyme which leads to its limitations in photosynthetic rates.
Significance·        Plays a central role in carbon fixation, serving as the starting point for the synthesis of organic compounds in plants and other photosynthetic organisms.·        Improving Rubisco’s efficiency is an active area of research in crop improvement for higher yield.