1. Carbohydrates Monosaccharides – e.g. glucose, fructose, galactose
General formula (CH2O)n (n=3-7)
3C = triose
5C = pentose
6C = hexose
Disaccharides – e.g.
sucrose – glucose+fructose
lactose – glucose+galactose
maltose – glucose+glucose
Polysaccharides – e.g.
starch, glycogen, cellulose – 000’s glucose molecules.

2. The Different Isomers of GlucoseOH H HO
CH2OH  

3. NUMBERS! 6 O OH H HO
CH2OH 5 4 1 3 2

4. Condensation Reaction & the Glycosidic BondOH H HO
CH2OH O OH H HO
CH2OH
H2O

5. MALTOSE (a dissacharide)OH H
CH2OH HO
1,4 glycosidic bond
Monosaccharides are joined by a condensation reaction. (Water is eliminated).
A glycosidic bond is formed producing a disaccharide.

6. Hydrolysis of carbohydrates
CH2OH HO
H2O

7. A glycosidic bond is broken.OH H HO
CH2OH O OH H HO
CH2OH
Polysaccharides and disaccharides are split by a hydrolysis reaction. (Water is required).
A glycosidic bond is broken.

8. Plants Animals Starch Cellulose Glycogen Storage Structure Storage
Carbohydrates
Storage
Structure
Starch
Cellulose
Glycogen
Plants
Animals
Storage
Gklue tick box into notes. Students complete it as you go along. And add any extra notes

9.  Starch - Amylose 6 5 4 1 3 2 These are 1,4 glycosidic bonds O OH HHO
CH2OH  5 4 1 3 2 O OH H HO
CH2OH O OH H HO
CH2OH O OH H HO
CH2OH O OH H HO
CH2OH
These are 1,4 glycosidic bonds

10. Starch - Amylose Spiral shape makes it compact and largely insoluble.
Does not affect osmosis or diffuse out of cells.
This makes it a good storage molecule.
Is hydrolysed slowly to α-glucose for use in respiration by amylase.

11.  Glycogen 6 5 1 4 3 2 1,6 glycosidic bond 1,4 glycosidic bonds O OH HHO
CH2OH  O OH H HO
CH2OH O OH H HO
CH2OH
1,6 glycosidic bond O OH H HO
CH2OH
1,4 glycosidic bonds

12. Glycogen Large and mostly insoluble.
Does not affect osmosis or diffuse out of cells.
Has many terminal glucose molecules.
Is hydrolysed quickly to α-glucose for respiration by glycogen phosphorylase.
Lucose

13. Cellulose  These are still 1,4 glycosidic bonds CH2OH O OH H HO CH2OH

14. Cellulose

15. Cellulose
Formation of hydrogen bonds now possible

16. Cellulose
Adjacent chains held together with hydrogen bonds to form microfibrils
Prevents hydrogen bonding with water so cellulose is highly insoluble
Strong microfibrils able to form a dense network to build cell walls.

18. Starch α
Unbranched chains of a-glucose held together with 1,4, glycosidic links.
Angle of OH groups involved in glycosidic links produces a spiral molecule.
Able to form limited hydrogen bonds with water so is only slightly soluble in water.
Broken down (slowly) to a-glucose with digestive enzymes for slow release of glucose for respiration
Molecule is compact and insoluble so does not affect osmosis
Will not diffuse out of cells
Glycogen
Branched chains of a-glucose held together with 1,4, glycosidic links and 1,6 glycosidic links.
Branches produce many terminal glucose molecules.
Broken down readily to a-glucose with digestive enzymes for quick release of glucose for respiration
Cellulose β
Long chains of B-glucose held together with 1,4 glycosidic links.
Adjacent chains are held together by crosslinks of hydrogen bonds to form microfibrils.
OH groups are unavailable to form hydrogen bonds with water molecules so cellulose is highly insoluble.
Difficult to hydrolyse with digestive enzymes
Strong and insoluble
Forms a dense matrix
Used to build cell walls