Carbohydrates

Carbohydrates

• made of the elemnts carbon, hydrogen and oxygen.
• monomers= monosaccharide
• 2 monosaccharides= disaccharide
• many monosaccharides= polysaccharides

monosaccharides are single sugar units that cannot be hydrolysesd to give a simpler sugar

Polysaccharide is a carbohydrate whose molecules consists of a number of sugar molecule that are bonded together

Reducing sugars is a sugar that can donate electrons to or reduce another chemical

Monosachharide

monosaccharides are the single sugar units that all carbohydrates are built from. have the general formula (CH2O)n

glucose has the formula C6H12O6. there are 2 isomers of glucose, alpha and beta glucose. The isomers dffer in the position of the Oh group on carbon-1      

Disaccharides

are double suagr units tat are formed as a result of a condensatin reaction,

A condensation react  is a chemical reaction in which 2 simple molecules combine together to form a more complex molecule with the elimination of a simple substance usually water.

A H2O molecule is discharged and a new bond forms between C1 of one glucose molecule and c4 of the other glucose molecule. A new bond forms which is called a glycosidic bond.

Addid water will break the glycosidic bond a realse the constituent monosaccharides this is a hydrolysis reaction.

Hydrolysis is the break down of a large molecule into smaller molecules by the addition of water.

Because the bon is between carbon-1 and carbon-4 of the molecules it is called a 1-4 glycosidic bond.

• alpha glucose + alpha glucose = maltose ( 1-4 glycosidic bond and formed in digestion of starch by amylose)
• gluocse + fructose = sucrose (1-2 glycosidic bond, found in plants)
• galactose + glucose = latose (1-4 glycosidic bond, found in milk)

Polysaccharides

Polymers formed by cobining many monomers gy glycosidic bonds formed by condensation reactions. Polysaccharodes are large molecules therefore or are insoluble and ideal for storgae. Some polysaccharodes can give structural support.

Starch

• is the plant storage polysaccharide
• found in plants as storage granuales, large amounts occur in seeds and storgae organs
• made of alpha glucose monomers
• plants store excess gluocse as starch
• main energy store in plants
• made up of 2 polymers- amylose and amylopectin

Amylose

• long unbranched chain of alpha glucose
• coiled helix structure
• 1-4 glycosidic bonds form
• helical structure makes it compact
• good for storage as large amount stored in sall space

Amylopectin

• long branched chain of alpha glucose
• mainly 1-4 glycosidic bonds
• 4% 1-6 glycosidic bonds are formed between the glucose units on the unbranched chain and the 1-6 glycosidic binds form between the branches
• 1-6 glycosidic linkages at branch points
• branches joined by 1-6 glycosidic bond
• 1-4 glycosidic bonds form between the unbranched chains

Amylopectin is a…