Mediaspace scheduled maintenance: Aug 25, 2026 07:00 - 12:00 AM. During this time, videos will be temporarily unavailable. Check status updates.

Lecture

Carbon fixation pathways

Description

This lecture covers the different pathways for carbon fixation, including the Calvin cycle, reductive citric acid cycle, and reductive acetyl-coA pathway. It explains the key enzymes, organisms involved, and the production of organic compounds. The lecture also discusses the hydroxypropionate bi-cycle and its significance in the assimilation of organic compounds by certain bacteria.

Official source

Ontological neighbourhood

Biology

Cell biology: Cell metabolism, Photosynthesis

Related concepts (32)

Biological carbon fixation

Biological carbon fixation or сarbon assimilation is the process by which inorganic carbon (particularly in the form of carbon dioxide) is converted to organic compounds by living organisms. The compounds are then used to store energy and as structure for other biomolecules. Carbon is primarily fixed through photosynthesis, but some organisms use a process called chemosynthesis in the absence of sunlight. Organisms that grow by fixing carbon are called autotrophs, which include photoautotrophs (which use sunlight), and lithoautotrophs (which use inorganic oxidation).

Citric acid cycle

The citric acid cycle —also known as the Krebs cycle, Szent-Györgyi-Krebs cycle or the TCA cycle (tricarboxylic acid cycle)—is a series of chemical reactions to release stored energy through the oxidation of acetyl-CoA derived from carbohydrates, fats, and proteins. The Krebs cycle is used by organisms that respire (as opposed to organisms that ferment) to generate energy, either by anaerobic respiration or aerobic respiration. In addition, the cycle provides precursors of certain amino acids, as well as the reducing agent NADH, that are used in numerous other reactions.

Calvin cycle

The Calvin cycle, light-independent reactions, bio synthetic phase, dark reactions, or photosynthetic carbon reduction (PCR) cycle of photosynthesis is a series of chemical reactions that convert carbon dioxide and hydrogen-carrier compounds into glucose. The Calvin cycle is present in all photosynthetic eukaryotes and also many photosynthetic bacteria. In plants, these reactions occur in the stroma, the fluid-filled region of a chloroplast outside the thylakoid membranes.

C3 carbon fixation

DISPLAYTITLE: C3 carbon fixation carbon fixation is the most common of three metabolic pathways for carbon fixation in photosynthesis, the other two being and CAM. This process converts carbon dioxide and ribulose bisphosphate (RuBP, a 5-carbon sugar) into two molecules of 3-phosphoglycerate through the following reaction: CO2 + H2O + RuBP → (2) 3-phosphoglycerate This reaction was first discovered by Melvin Calvin, Andrew Benson and James Bassham in 1950. C3 carbon fixation occurs in all plants as the first step of the Calvin–Benson cycle.

C4 carbon fixation

carbon fixation or the Hatch–Slack pathway is one of three known photosynthetic processes of carbon fixation in plants. It owes the names to the 1960s discovery by Marshall Davidson Hatch and Charles Roger Slack that some plants, when supplied with 14, incorporate the 14C label into four-carbon molecules first. fixation is an addition to the ancestral and more common carbon fixation. The main carboxylating enzyme in photosynthesis is called RuBisCO, which catalyses two distinct reactions using either (carboxylation) or oxygen (oxygenation) as a substrate.

Related lectures (31)

Photosynthesis: Anoxygenic Phototrophs and Carbon Fixation

Explores photosynthesis in anoxygenic phototrophs and the mechanisms of carbon fixation.

Carbon Fixation: Processes and Pathways

Explores the critical process of carbon fixation by primary producers, covering pathways and key enzymes involved.

Carbon Fixation: Pathways and Organisms

Explores carbon fixation pathways and key enzymes used by autotrophic organisms to convert CO2 to organic carbon.

Metabolic Pathways: Diversity and Fixation

Delves into metabolic pathways, energy-rich compounds, and fermentation processes, emphasizing the importance of biofuels as an alternative to fossil fuels.

Metabolic Diversity: Fermentation and Energy Production