Amylose: Difference between revisions
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'''Amylose''' is a linear polymer of glucose that occurs in starch. It occurs in foods such as grains and potatoes, and it is a major source of energy (calories) in most diets. There are three major forms of amylose, A, B, and V, that differ in the three-dimensional structure. Amylose can also occur with an undefined structure, for example when cooked in water. Amylose is distinct from amylopectin, which is a branched polymer of glucose, and from cellulose, which is a linear polymer of glucose that differs in stereochemistry from amylose. | '''Amylose''' is a linear polymer of glucose that occurs in starch. It occurs in foods such as grains and potatoes, and it is a major source of energy (calories) in most diets. There are three major forms of amylose, A, B, and V, that differ in the three-dimensional structure. Amylose can also occur with an undefined structure, for example when cooked in water. Amylose is distinct from amylopectin, which is a branched polymer of glucose, and from [[cellulose]], which is a linear polymer of glucose that differs in stereochemistry from amylose. | ||
==Structure== | ==Structure== | ||
<StructureSection load='' size='340' side='right' caption='Caption for this structure' scene='82/824003/ | <StructureSection load='' size='340' side='right' caption='Caption for this structure' scene='82/824003/Amylose_v/4'> | ||
<scene name='82/824003/Amylose_a/3'>Amylose A</scene> and B occur as parallel double-helices of glucose chains, with 6 glucose units per turn. In contrast, <scene name='82/824003/Amylose_v/2'>amylose V</scene> occurs as a single helix as shown in the figure (same structure shown as <scene name='82/824003/Amylose_v/3'>cartoon</scene>). A more irregular conformation of a cyclic amylose occurs is found in complex with a protein in the structure [[5jiw]]. | |||
</StructureSection> | </StructureSection> | ||
== References == | == References == | ||
<references/> | <references/> | ||
Latest revision as of 21:02, 29 September 2020
Amylose is a linear polymer of glucose that occurs in starch. It occurs in foods such as grains and potatoes, and it is a major source of energy (calories) in most diets. There are three major forms of amylose, A, B, and V, that differ in the three-dimensional structure. Amylose can also occur with an undefined structure, for example when cooked in water. Amylose is distinct from amylopectin, which is a branched polymer of glucose, and from cellulose, which is a linear polymer of glucose that differs in stereochemistry from amylose.
StructureStructure
and B occur as parallel double-helices of glucose chains, with 6 glucose units per turn. In contrast, occurs as a single helix as shown in the figure (same structure shown as ). A more irregular conformation of a cyclic amylose occurs is found in complex with a protein in the structure 5jiw.
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