Biological Molecules
Carbohydrates
Glycogen Starch Cellulose
Amylose Amylopectin
Animal cells - en- Plant cells - en- Plant cell walls
ergy store ergy store (com-
pact and insolu-
ble)
1,4 and 1,6 glyco- 1,4 glycosidic 1,4 and 1,6 glyco-
sidic bonds bonds sidic bonds
Alpha Glucose Alpha glucose Beta glucose
Branched (more Compact, coiled Branched - allows Straight chain (alter-
branched and shape folding to be com- nating glycosidic bond
more terminal pact due to position of -OH
ends than starch) and -H group)
CONTAINS HYDRO-
GEN BONDS
Compact - more
1,6 glycosidic
bonds compared
to amylopectin so
more compact
Insoluble Insoluble
Easily synthesised
- rapidly responds
to insulin
Starch
Soluble starch - partially hydrolysed into shorter glucose chains
(this reduces starch size so water can surround the molecules)
Cellulose
Breaking it down
- Microorganisms possess enzymes to hydrolyse cellulose
- Grazing animals carry bacteria in their gut to digest it
- Humans cannot digest it
- Incomplete digestion results in methane
Role
1
,Provides strength in cell wall
- H bonds between parallel strands form microfibrils
- Cellulose fibres and other molecules (e.g.) lignin in the cell wall form a matrix
Breaking a glycosidic bond
Enzyme hydrolysis
- mix w enzymes at room temp
Acid hydrolysis
- boil in a sample with dilute HCL
Separating monosaccharides
- Chromatography - dot solution and put in solvent
- largest molecules will travel slower
- Mixture separates into different spots
- Can compare by matching them with Rf values of known monosaccharides and look
for the same values (same distance travelled)
Glucose vs Fructose
- Both hexose sugars
- C6H12O6
- Glucose - 6 atom ring
- Fructose - 5 atom ring
Condensation reaction
- forms glycosidic bond
- chains formed by 1,4 bond
- Branches formed by 1,6 bond
2
, - water is produced as a product
Stock solution
- (desired concentration / concentration of stock) x volume needed
Lipids
Triglyceride
3
Carbohydrates
Glycogen Starch Cellulose
Amylose Amylopectin
Animal cells - en- Plant cells - en- Plant cell walls
ergy store ergy store (com-
pact and insolu-
ble)
1,4 and 1,6 glyco- 1,4 glycosidic 1,4 and 1,6 glyco-
sidic bonds bonds sidic bonds
Alpha Glucose Alpha glucose Beta glucose
Branched (more Compact, coiled Branched - allows Straight chain (alter-
branched and shape folding to be com- nating glycosidic bond
more terminal pact due to position of -OH
ends than starch) and -H group)
CONTAINS HYDRO-
GEN BONDS
Compact - more
1,6 glycosidic
bonds compared
to amylopectin so
more compact
Insoluble Insoluble
Easily synthesised
- rapidly responds
to insulin
Starch
Soluble starch - partially hydrolysed into shorter glucose chains
(this reduces starch size so water can surround the molecules)
Cellulose
Breaking it down
- Microorganisms possess enzymes to hydrolyse cellulose
- Grazing animals carry bacteria in their gut to digest it
- Humans cannot digest it
- Incomplete digestion results in methane
Role
1
,Provides strength in cell wall
- H bonds between parallel strands form microfibrils
- Cellulose fibres and other molecules (e.g.) lignin in the cell wall form a matrix
Breaking a glycosidic bond
Enzyme hydrolysis
- mix w enzymes at room temp
Acid hydrolysis
- boil in a sample with dilute HCL
Separating monosaccharides
- Chromatography - dot solution and put in solvent
- largest molecules will travel slower
- Mixture separates into different spots
- Can compare by matching them with Rf values of known monosaccharides and look
for the same values (same distance travelled)
Glucose vs Fructose
- Both hexose sugars
- C6H12O6
- Glucose - 6 atom ring
- Fructose - 5 atom ring
Condensation reaction
- forms glycosidic bond
- chains formed by 1,4 bond
- Branches formed by 1,6 bond
2
, - water is produced as a product
Stock solution
- (desired concentration / concentration of stock) x volume needed
Lipids
Triglyceride
3
