Tärkkelysmolekyylejä

Tärkkelysmolekyylejä are complex carbohydrates found in plants, serving as a primary energy storage form. They are polymers composed of glucose units linked together. The two main types of starch molecules are amylose and amylopectin.

Amylose is a linear, unbranched polysaccharide chain. The glucose units are linked by alpha-1,4 glycosidic bonds, which give the molecule a helical structure. Amylose typically constitutes about 20-30% of starch.

Amylopectin, on the other hand, is a branched polysaccharide. In addition to the alpha-1,4 glycosidic bonds found in amylose, amylopectin also contains alpha-1,6 glycosidic bonds at branching points. These branches create a more spherical and complex structure. Amylopectin makes up the remaining 70-80% of starch.

The structure of starch molecules dictates its physical and chemical properties, including its solubility in water and its digestibility. When ingested by animals, starch is broken down into glucose units by enzymes, providing a source of energy. In plants, starch is stored in granules within cells, particularly in seeds, roots, and tubers. The relative proportions of amylose and amylopectin vary depending on the plant source, affecting the texture and properties of foods derived from them. For example, starches high in amylose tend to form gels that are more firm and brittle, while those high in amylopectin form softer gels.