Tuesday 2 September 2008

Summary 5.2

-sugars contain the elements carbon, hydrogen and oxygen, ratio of 1:2:1
-at the core of most sugar molecules found in nature are carbon skeletons that have a ring shape
-carbohydrate is an organic compound made up of sugar molecules
-simple sugars contain one sugar unit, monosaccharides eg) glucose, frutose and glactose.
-glucose exist in both straight chain and ring shaped forms

-sugar molecules, glucose are main supply for cellular work.

-cells break down glucose molecules and extract their stored energy (mostly not used immediately incorporated into larger carbogydrate)

-disaccharide, cell constructed by two monosaccharide.

-sucrose can be broken down into glucose and frucose and used right away. Body can store these after use.

-sucrose consist of a glucose molecule linked to fuctose molecule.

-when plants break down starch molecules, the stored glucose becomes available.

-humans and animals use plant starch for digestive system

-glycogen mostly stored in liver and muscle cells

-when body needs energy it breaks down glycogen and release glucose.

-cellulose and some of starch are not soluble.

Concept Check 5.2

1.Explain the difference between a monosaccharide and a disaccharide. Give an example of each.

Monosaccharide is one sugar unit and disaccharide is two sugar unit. Glucose, fractrose, and glactose are example of monossacharide and sucrose is an example of disaccharide.

2.Compare and contrast starch, glycogen, and cellulose.

Starch is a polysaccharide found in plant cell, glycogen is polysaccharide found in animals and cellulose is aso polysaccharides in plant that serves building materials.

3.How do animals store excess glucose molecules?

Animals store excess glucose molecules in a form of polysaccharide.

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