carbohydrates. carbohydrates are made from carbon, hydrogen and oxygen plant cell walls depend on...
TRANSCRIPT
Carbohydrates
CarbohydratesCarbohydrates are made from CARBON, HYDROGEN and OXYGEN
Plant cell walls depend on the structural role of some carbohydrates
They STORE ENERGY in plants and animals
MONOSACCHARIDES
CARBOHYDRATES
POLYSACCHARIDESDISACCHARIDES
(CH2O)n
MonosaccharidesMonosaccharides are small organic molecules used as bulding blocks for more complex carbohydrates. Click each of the blue boxes to work through the slide.
General FormulaWhat does the ‘n’
stand for?
Number of Carbon atoms
So, when n=3TRIOSE, e.g. glyceraldehyde -
In metabolic reactions
When n=5 When n=6
HEXOSE, e.g. glucose -
main source of energy
PENTOSE, e.g. ribose –
formation of nucleic acid
Isomerism in Glucose C6H12O6
CH2OH
CH2OH
Alpha-glucose
beta-glucose
Show structural change
Oxygen
Hydrogen
Carbon
Hydroxide (OH)
GLUCOSE
MALTOSESUCROSE
GLUCOSE
GLUCOSE
Disaccharides
A disaccharide can be made from two of the same
monosaccharide molecule or from two different ones.
Disaccharides form when two monosaccharide units join forming a
glycosidic bond, by a condensation reaction.
The combination of monosaccharides determines which disaccharide is formed.
MONOSACCHARIDES DISACCHARIDE
FRUCTOSEGALACTOSE
WATERWATERWATER
LACTOSE
GLUCOSE
OOHOH
Forming Disaccharides
C C
C
C O
C
H
OH
OHOH
OH
HH
CH2OH
H
H
CH2OH
C C
C
C O
C
H
OH
OHOH
OH
HH
CH2OH
H
H
C C
C
C O
C
H
OH
OH
OH
HH
CH2OH
H
H
C C
C
C O
C
H
OH
OH
OH
HH
CH2OH
H
H O
H H
PolysaccharidesPolysaccharides are large complex molecules known as
POLYMERS.
Monomers are the individual monosaccharides which join to form the polysaccharide.
Polymerisation is the process of bonding many MONOMERS by condensation reactions to form one large molecule.
Po
lys
acc
har
ide
s Monomer Glycosidic bond
GLYCOGEN α Glucose 1-4 and 1-6
STARCH α Glucose 1-4
CELLULOSE β Glucose 1-4 and 1-6
What is polymerisation?
What is a monomer?
OOHOH
Forming polysaccharides
C C
C
C O
C
H
OH
OH
HH
CH2OH
H
H
C C
C
C O
C
H
OH
OH
OH
HH
CH2OH
H
H
O
H H
In this example, 3 condensation reactions have produced 3 water molecules to produce the polysaccharide.
O
H H
C C
C
C O
C
H
OH
OH
OH
HH
CH2OH
H
H
C C
C
C O
C
H
OH
OH
HH
CH2OH
H
H
OHOH OHOH
Glucose
O
O
H H
O
A HYDROLYSIS reaction (addition of water) reverses the reaction and splits the polysaccharide releasing 3 monosaccharide molecules.
You can give this question a go, in order to prove your understanding: