HideShow resource information

Structure of Carbs

Contain O,H,C

H and O are present in the ratio 2:1

3 Carbons = Triose E.G Glyceraldehyde 

5 Carbons = Pentose E.G Rhybose

6 Carbons = Hexose E.G Glucose

1 of 11


Monomers = basic units of carbohydrates. (Structural isomer has same elements in same amounts, but in a different structure )

(*yr-6rCWsA9cTLEKtwZgRRzDy6*JM*OLg_/glucose.gif)Alpha glucose molecule,

2 of 11

Beta Glucose

( Glucose

3 of 11


2 monosaccharides = 1 Disaccharides

Joined by a condensation reaction --> Always results in loss of water 

( 2 alpha glucose = maltose

4 of 11

Disaccharides (2


Disaccharides are as follows -

2 alpha glucose = maltose --> Found in malt sugar and barley

1 Alpha glucose + fructose  = Sucrose ---> Cane sugar

1 Alpha glucpse + galactose  = Lactose ---> Milk sugar

Maltose and Lactose = reducing sugars

5 of 11


Many monosaccaride monomers.

Starch and glycogen = energy storage molecules. ( Need to related there structures to this)

1) They're insoluble = Osmosis can't take place in cells containing starch/glycogen. Also they're large molecules and can't pass through cell membranes. Can't be washed out. So.. because of their large size they are insoluble.

2)The molecules are coiled. This means they're compact hence a large quantity can be stored in a small space in cells.

3)The branches have many terminal ends. Glucose units are able to be released quickly for respiration.

6 of 11

Starch 1) Amylose.

Formed by condensation of many alpha glucose molucules. 2 forms.

Amylose -

Storage molecule. Stores Glucose in plant cells.

Where it's straight = Carbon 1-4 Glycosidic bond.

Where it kinks = Carbon 1-6 Glycosidic bond.

7 of 11

Starch 2) Amylopectin

Branched form = can be easily mobilized. Amylaze can digest this quicker.

Storage molecule. Stores glucose in plant cells.

Carbon 1 -4 glycosidic bonds

Carbon 1-6 glycosidic bonds

8 of 11


Formed by condensation of glucose molecules

The storage carbohydrate of animal cells. More branches than starch mobilized quicker.

Found in large amounts in the liver and muscle cells.

9 of 11


Made from Beta Glucose. difference with alpha = OH group on carbon 1 is inverted.

When Beta glucoses condense together everyother molecule inverts = goes upside down 180degrees.

Different from starch and glycogen in that it forms strong straight chains. Everyother hydroxl group can form hydrogen bonds. which = structural stability to cell walls.

Many Cellulose chains together = micro fibrils, which are used to form cell walls of plant cells. Give strength and rigidity. Cellulose = structural molecule.

Celluloses high tensile strength is because ..

  • Long chains cross linked by hydrogen bonds
  • Adjacent glucose molecules inverted by 180
  • Hydrogen bonds form between hydroxyl groups of adjacent parallel chains = make up micro fibrils.
10 of 11


Similar to cellulose but has amino acids added to form a mucopolysaccharide.


  • Strong
  • Waterprood
  • Lightweight
  • Forms exoskeleton of insects
  • Contains nitrogen
11 of 11


No comments have yet been made

Similar Biology resources:

See all Biology resources »See all Biological molecules, organic chemistry and biochemistry resources »