sucrose biosynthetic process

Definition

Target type: biologicalprocess

The chemical reactions and pathways resulting in the formation of sucrose, the disaccharide fructofuranosyl-glucopyranoside. [GOC:go_curators]

The sucrose biosynthetic process is a fundamental pathway in plant metabolism, responsible for the production of sucrose, the primary form of sugar transported throughout the plant. This process occurs primarily in the cytosol of photosynthetic cells, specifically in the mesophyll cells of leaves. The synthesis of sucrose involves the condensation of two simple sugars, glucose and fructose, catalyzed by the enzyme sucrose phosphate synthase (SPS).

The process begins with the phosphorylation of glucose by the enzyme hexokinase, forming glucose-6-phosphate. Glucose-6-phosphate is then isomerized to fructose-6-phosphate by phosphoglucose isomerase. Fructose-6-phosphate is further phosphorylated to fructose-1,6-bisphosphate by phosphofructokinase.

Fructose-1,6-bisphosphate is cleaved into dihydroxyacetone phosphate (DHAP) and glyceraldehyde-3-phosphate (G3P) by the enzyme aldolase. DHAP is converted to G3P by the enzyme triose phosphate isomerase.

Two molecules of G3P are then combined to form fructose-1,6-bisphosphate, which is then dephosphorylated to fructose-6-phosphate by the enzyme fructose-1,6-bisphosphatase.

The fructose-6-phosphate is then converted to glucose-6-phosphate by the enzyme glucose-6-phosphatase. Glucose-6-phosphate is then converted to glucose by the enzyme glucose-6-phosphate dehydrogenase.

Glucose and fructose are then combined by the enzyme sucrose phosphate synthase (SPS) to form sucrose-6-phosphate.

Sucrose-6-phosphate is then dephosphorylated by the enzyme sucrose phosphatase to form sucrose.

Sucrose is then transported throughout the plant via the phloem, where it serves as a source of energy and carbon for growth and development.'
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Proteins (1)

Compounds (23)