Cellodextrins are

glucose Glucose is a simple sugar with the molecular formula . Glucose is overall the most abundant monosaccharide, a subcategory of carbohydrates. Glucose is mainly made by plants and most algae during photosynthesis from water and carbon dioxide, u ...

polymers ( polysaccharides) of varying length (two or more glucose monomers) resulting from

cellulolysis Cellulose is an organic compound with the formula , a polysaccharide consisting of a linear chain of several hundred to many thousands of β(1→4) linked D-glucose units. Cellulose is an important structural component of the primary cell wall ...

, the breakdown of

cellulose Cellulose is an organic compound with the formula , a polysaccharide consisting of a linear chain of several hundred to many thousands of β(1→4) linked D-glucose units. Cellulose is an important structural component of the primary cell w ...

Classification

A cellodextrin is classified by its

degree of polymerization The degree of polymerization, or DP, is the number of monomeric units in a macromolecule or polymer or oligomer molecule. For a homopolymer, there is only one type of monomeric unit and the ''number-average'' degree of polymerization is given b ...

(DP) which indicates the number of linked glucose monomers it contains. Each glucose monomer is linked via a ''beta''-1,4

glycosidic bond A glycosidic bond or glycosidic linkage is a type of covalent bond that joins a carbohydrate (sugar) molecule to another group, which may or may not be another carbohydrate. A glycosidic bond is formed between the hemiacetal or hemiketal group ...

. The most common cellodextrins are listed below: * cellobiose (DP=2) (sometimes not included in cellodextrin classification) * cellotriose (DP=3) * cellotetraose (DP=4) * cellopentaose (DP=5) * cellohexaose (DP=6)

Function

Cellodextrins are created through the cleavage of cellulose in most

anaerobic bacteria An anaerobic organism or anaerobe is any organism that does not require molecular oxygen for growth. It may react negatively or even die if free oxygen is present. In contrast, an aerobic organism (aerobe) is an organism that requires an oxygenat ...

by the

cellulosome Cellulosomes are multi-enzyme extracellular complexes. Cellulosomes are associated with the cell surface and mediate cell attachment to insoluble substrates and degrade them to soluble products which are then absorbed. Cellulosome complexes are in ...

(an amalgamation of

cellulolytic Cellulose is an organic compound with the formula , a polysaccharide consisting of a linear chain of several hundred to many thousands of β(1→4) linked D-glucose units. Cellulose is an important structural component of the primary cell wall ...

enzyme Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products ...

s on the outside of a cell). An

endoglucanase Cellulase (EC 3.2.1.4; systematic name 4-β-D-glucan 4-glucanohydrolase) is any of several enzymes produced chiefly by fungi, bacteria, and protozoans that catalyze cellulolysis, the decomposition of cellulose and of some related polysaccharide ...

first cuts the crystalline cellulose in an amorphous zone and exoglucanases subsequently cleave these large insoluble chunks of cellulose into smaller, soluble cellodextrins which can be used by the cell. Many cellulolytic bacteria use cellodextrins as their primary source of energy. The energy is obtained through the phosphorolytic cleavage of

glycosidic A glycosidic bond or glycosidic linkage is a type of covalent bond that joins a carbohydrate (sugar) molecule to another group, which may or may not be another carbohydrate. A glycosidic bond is formed between the hemiacetal or hemiketal group ...

bonds as well as the anaerobic glycolysis of the glucose monomers. Transport of cellodextrins across the

cell membrane The cell membrane (also known as the plasma membrane (PM) or cytoplasmic membrane, and historically referred to as the plasmalemma) is a biological membrane that separates and protects the interior of all cells from the outside environment ( ...

is usually an active process, requiring ATP.

References

{{Reflist Polysaccharides Cellulose

Classification

Function

See also

References