Starch

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== Structure  ==
 
== Structure  ==
  
Starch is a [[Polysaccharide|polysaccharide]] with the basic [[Monosaccharide|monosaccharide]] being [[Glucose|glucose]]. the [[Glucose|glucose]] molecules are joined together by [[Glycosidic bonds|glycosidic bonds]]&nbsp;straight chains are made up of 1-4 glycosidic bonds while branching chain are made up of 1-6 glycosidic bonds. Starch is made up of two fractions: [[Amylose|amylose]] and [[Amylopectin|amylopectin]]. Natural starches are made up of about 20% [[Amylose|amylose]] and 80% [[Amylopectin|amylopectin]]. [[Amylose|Amylose]] is soluble in hot water whereas [[Amylopectin|amylopectin]] is insoluble. [[Amylose|Amylose]] has no branching chains, but instead is made up of only 1-4 [[Glycosidic bonds|glycosidic bonds]]. This causes the [[Amylase|amylase]] to form a [[Alpha-helix|helix]] shape. [[Amylopectin|Amylopectin]] however contains both straight chains and branching chains.<br>  
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Starch is a [[Polysaccharide|polysaccharide]] with the basic [[Monosaccharide|monosaccharide]] being [[Glucose|glucose]]. the [[Glucose|glucose]] molecules are joined together by [[Glycosidic bonds|glycosidic bonds]]&nbsp;straight chains are made up of 1-4 glycosidic bonds while branching chain are made up of 1-6 glycosidic bonds. Starch is made up of two fractions: [[Amylose|amylose]] and [[Amylopectin|amylopectin]]. Natural starches are made up of about 20% [[Amylose|amylose]] and 80% [[Amylopectin|amylopectin]]. [[Amylose|Amylose]] is soluble in hot water whereas [[Amylopectin|amylopectin]] is insoluble. [[Amylose|Amylose]] has no branching chains, but instead is made up of only 1-4 [[Glycosidic bonds|glycosidic bonds]]. This causes the amylose&nbsp;to form a [[Alpha-helix|helix]] shape. [[Amylopectin|Amylopectin]] however contains both straight chains and branching chains.<br>
  
 
== Testing  ==
 
== Testing  ==

Revision as of 16:02, 27 November 2012

Structure

Starch is a polysaccharide with the basic monosaccharide being glucose. the glucose molecules are joined together by glycosidic bonds straight chains are made up of 1-4 glycosidic bonds while branching chain are made up of 1-6 glycosidic bonds. Starch is made up of two fractions: amylose and amylopectin. Natural starches are made up of about 20% amylose and 80% amylopectin. Amylose is soluble in hot water whereas amylopectin is insoluble. Amylose has no branching chains, but instead is made up of only 1-4 glycosidic bonds. This causes the amylose to form a helix shape. Amylopectin however contains both straight chains and branching chains.

Testing

Starch can be tested for using iodine solution. If starch is present then a dark blue-black colour will be seen. This dark blue-black colour is due to the iodine reacting with the amylose helix.


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