POLYSACCHARIDES
• Macromolecules• Common ones based upon glucose
Branched polysaccharides• Amylose & amylopectin (starches) are
synthesised in plants.• Glycogen is synthesised in animals, more
highly branched than starches = more compact
Unbranched polysaccharides Cellulose in plant cell walls
© 2007 Paul Billiet ODWS
LIPIDS C, H, O
• More hydrogen (more reduced) than carbohydrates.
• Insoluble in water, soluble in organic solvents (alcohols, acetone, chloroform etc)
© 2007 Paul Billiet ODWS
FATTY ACIDS: CARBOXYLIC ACID + LONG HYDROCARBON CHAIN
CO
OHCH3
Carboxylic acid
Hydrocarbon chain
A saturated fatty acid
An unsaturated fatty acid
C
O
OH
CH3
Saturated fatty
acids
Unsaturated fatty
acids
no double bonds one or more double
bonds
abundant in fats abundant in oils
more reduced less reduced
more energy less energy
high melting point low melting point
THE MAJOR FUNCTION OF LIPIDS…
Used by the organism as:
1. Stored Energy Source
2. Chemical messengers3. Major part of cell membranes
The Degree Of Saturation In A Fat Affects Its Physical And Nutritional Properties
saturated
monounsaturated
polyunsaturated
Sterols Are Part of Cellular Membranes and Act as Hormones
Note the four ring structure common to all sterols.
Hydrophilic Head Group And Hydrophobic Tails: Keys To Phospholipid Function
Phospholipids have a Jekyll and Hyde personality.
Phospholipids are Building Blocks of Cellular Membranes
The hydrophilic head group and hydrophobic tails are the keys to phospholipid function.
Protein
THE key elements of life.Forget DNA, proteins rule.
PROTEIN STRUCTURE DEPENDENT UPON PROTEIN FUNCTION!
Peptide bonds
Amino Acids, Peptide Bonds, Polypeptides, Protein
Proteins are linear chains of 20 different building blocks called amino acids.
Amino acids are linked by peptide bonds – a form of covalent bond.
ENZYMES WORK BY…
Lowering the ACTIVATION ENERGY (EA)
of chemical reactions!
WHAT IF THERE WERE NO ENZYMES IN ORGANISMS?
• enzymes are usually named with the suffix -aseex: protease
lipaselactase
• enzymes are specific !!!!specific enzymes for specific substrates!
NUCLEIC ACID FUNCTIONS
DNADeoxyribonucleic Acid
contains genetic info.RNA
Ribonucleic Acidaids in making proteins