structure of Starch complete lecture |starch deep concept#biochemistry #education
2structure of starch
starch
structure of starch in hindi
starch structure
structure starch
structure of starch in tamil
how to draw structure of starch
structure of amylose
structure of glycogen
structure of cellulose
sources of starch
the structure of polysaccharides
structure of amylopectin
types of starch
how to draw structure of glucose
explain structure of cellulose
application of starch
structure of cellulose chemistry class 12
Starch or amylum is a polymeric carbohydrate consisting of numerous glucose units joined by α-(1→4)-D glycosidic bonds. This polysaccharide is produced by most green plants for energy storage. Worldwide, it is the most common carbohydrate in human diets, and is contained in large amounts in staple foods such as wheat, potatoes, maize (corn), rice, and cassava (manioc).
Pure starch is a white, tasteless and odorless powder that is insoluble in cold water or alcohol. It consists of two types of molecules: the linear and helical amylose and the branched amylopectin. Depending on the plant, starch generally contains 20 to 25% amylose and 75 to 80% amylopectin by weigh
While amylose was thought to be completely unbranched, it is now known that some of its molecules contain a few branch points.[36] Amylose is a much smaller molecule than amylopectin. About one quarter of the mass of stored starch in plants consist of amylose, although there are about 150 times more amylose than amylopectin molecules.
Accumulated starch within plants is stored in semi-crystalline granules. Each plant species has a unique starch granular size: rice starch is relatively small (about 2 μm), potato starches have larger granules (up to 100 μm) and wheat and tapioca all in-between.[37] Unlike other botanical sources of starch, wheat starch has a bimodal size distribution, with both smaller and larger granules ranging from 2 to 55 μm.[37]
Some cultivated plant varieties have pure amylopectin starch without amylose, known as waxy starches. The most used is waxy maize, others are glutinous rice and waxy potato starch. Waxy starches undergo less retrogradation, resulting in a more stable paste. A maize cultivar with a relatively high proportion of amylose starch, amylomaize, is cultivated for the use of its gel strength and for use as a resistant starch (a starch that resists digestion) in food products.
Synthetic amylose made from cellulose has a well-controlled degree of polymerization. Therefore, it can be used as a potential drug deliver carrier.