Section of a starch molecule © Siemens Stiftung 2016 CC BY-SA 4.0 international

Section of a starch molecule

Image

Chemical structural formula:
Section of a starch molecule showing the alpha-1,4 glycosidic bonds in amylose.

English, Spanish, German
Image (68.3 kByte)
2017-10-11
Starch is a prominent example of plant polysaccharides. It has a soluble component (25%) and an insoluble component (75%). The soluble component, the amylose, forms long chains that coil up into an alpha-helix. By contrast, the insoluble component, the amylopectin, is highly branched with additional bonds between shorter chain sections. Amylose can be specifically detected using iodine. Iodine is deposited inside the alpha-helix of the starch molecule. This results in a complex that has a distinctive color ranging from deep blue, blue-violet, to black, depending on the iodine concentration.

Information and ideas:
Glycogen, the storage for carbohydrates in animals, is comparable in structure to amylopectin.
Illustration
Biology; Chemistry
Grade 10 to 13
Middle/high school
Carbohydrate; Metabolism; Molecule; Nutrition
Siemens Stiftung Media Portal
MediaHouse GmbH
© Siemens Stiftung 2016
Stay up-to-date!

About four times a year, we inform you about new media on this portal as well as current studies and events related to OER and STEM.

Media Portal newsletter – register now

About four times a year, we inform you about new media on this portal as well as current studies and events related to OER and STEM.

*Required fields


Language