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 ODWSODWS

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 ODWSODWS

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 C O OH CH3 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 fatsabundant in oils more reducedless reduced more energyless energy high melting pointlow 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

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 Peptide bonds 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

ENZYMES Special Proteins that help to increase the rate of chemical reactions. Aka “CATALYSTS”

ENZYMES WORK BY… Lowering the ACTIVATION ENERGY (E A ) 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…