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

LIPIDSComposed of

CARBONHYDROGEN

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

• OILSplant lipids

• WAXESplants and animals

BASIC Unit (monomer) of lipids are:

FATTY ACIDS +

GLYCEROL

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

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 messengers3. 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

EstrogenTestosterone 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

CARBONHYDROGEN

OXYGENNITROGEN

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

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.

Shape and Function of Proteins Depend on Amino Acid Sequence

ENZYMESSpecial 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 -aseex: protease

lipaselactase

• enzymes are specific !!!!specific enzymes for specific substrates!

ENZYMES ARE…

• Reusable!!

LOCK AND KEY MODEL INDUCED FIT MODEL

Nucleic Acids

Two Types:DNARNA

DNA

NUCLEIC ACIDSCOMPOSED OF

CARBONHYDROGEN

OXYGENNITROGEN

PHOSPHORUS

Basic Unit (monomer) of nucleic acids:

NUCLEOTIDES

Nucleotides are DNA and RNA Building Blocks

NUCLEIC ACID FUNCTIONS

DNADeoxyribonucleic Acid

contains genetic info.RNA

Ribonucleic Acidaids in making proteins

Another Function of Nucleotides…