THE MAJOR FUNCTION OF
CARBOHYDRATES…
Energy
PRODUCTION
(and
STORAGE)
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
Composed of
CARBON
HYDROGEN
OXYGEN
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
COMMONLY CALLED:
• FATS
animal lipids
• OILS
plant lipids
• WAXES
plants and animals
BASIC Unit (monomer) of lipids are:
FATTY ACIDS
+
GLYCEROL
FATTY ACIDS: CARBOXYLIC
ACID + LONG HYDROCARBON
CHAIN
A saturated fatty acid
Carboxylic acid
O
CH3
Hydrocarbon chain
C
OH
An unsaturated fatty acid
O
CH3
C
OH
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
Lipid  Fatty Acid chains
linked to Glycerol Head
Space-filling model
of a fat
A fatty acid
3 MAJOR CHEMICAL TYPES
Sterol
Fat
Phospholipid
THE MAJOR FUNCTION OF LIPIDS…
Used by the organism as:
1.
Stored Energy Source
2. Chemical messengers
3. Major part of cell membranes
The Degree
Of
Saturation
In A Fat
Affects Its
Physical
And
Nutritional
Properties
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.
Sterols As Hormones
Estrogen
Testosterone
Progesterone
LIPIDS ARE HYDROPHOBIC!
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.
Phospholipids Form Biological Membranes
PROTEINS
Composed of
CARBON
HYDROGEN
OXYGEN
NITROGEN
BASIC UNIT (monomer) of proteins
are:
AMINO ACIDS
Proteins are Linear Chains of Linked Amino Acids
Protein
THE key elements of life.
Forget DNA, proteins rule.
PROTEIN STRUCTURE DEPENDENT UPON PROTEIN FUNCTION!
Some of the Diverse Functions of Proteins
Amino Acids, Peptide Bonds, Polypeptides, Protein
Proteins are linear chains of 20 different building blocks called amino acids.
Peptide bonds
Amino acids are linked by peptide bonds – a form of
covalent bond.
Shape and
Function of
Proteins
Depend on
Amino Acid
Sequence
ENZYMES
Special Proteins that help to increase
the rate of chemical reactions.
Aka “CATALYSTS”
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 -ase
ex:
protease
lipase
lactase
• enzymes are specific !!!!
specific enzymes for specific
substrates!
ENZYMES ARE…
• Reusable!!
LOCK AND KEY MODEL
INDUCED FIT MODEL
Nucleic Acids
Two Types:
DNA
RNA
DNA
NUCLEIC
ACIDS
COMPOSED
OF
CARBON
HYDROGEN
OXYGEN
NITROGEN
PHOSPHORUS
Basic Unit (monomer) of nucleic acids:
NUCLEOTIDES
Nucleotides are
DNA and RNA
Building Blocks
NUCLEIC ACID FUNCTIONS
DNA
Deoxyribonucleic Acid
contains genetic info.
RNA
Ribonucleic Acid
aids in making proteins
Another Function of Nucleotides…