THE STRUCTURE AND FUNCTION OF

MACROMOLECULES

YOU MUST KNOW…• THE ROLE OF DEHYDRATION

SYNTHESIS IN THE FORMATION OF ORGANIC COMPOUNDS AND HYDROLYSIS IN THE DIGESTION OF ORGANIC COMPOUNDS

• HOW TO RECOGNIZE THE FOUR BIOLOGICALLY IMPORTANT ORGANIC COMPOUNDS BY THEIR STRUCTURAL FORMULAS

YOU MUST KNOW…• THE CELLULAR FUNCTIONS OF ALL

FOUR COMPOUNDS• THE FOUR STRUCTURAL LEVELS

THAT PROTEINS CAN GO THROUGH TO REACH THEIR FINAL SHAPE (CONFORMATION) AND THE DENATURING IMPACT THAT HEAT AND pH CAN HAVE ON PROTEIN STRUCTURE

CONCEPT 5.1

• MOST MACROMOLECULES ARE POLYMERS, BUILT FROM MONOMERS

• POLYMERS ARE LONG CHAINS OF MONOMERS

• CONDENSATION OR DEHYDRATION REACTIONS CREATE POLYMERS FROM MONOMERS. TWO MONOMERS ARE JOINED BY REMOVING ONE MOLECULE OF WATER

dehydrationMONOMERS POLYMERS reactions

H2O

• HYDROLYSIS OCCURS WHEN WATER IS ADDED TO SPLIT LARGE MOLECULES

H2O

hydrolysis

POLYMERS MONOMERS

CONCEPT 5.2• CARBOHYDRATES SERVE AS

FUEL AND BUILDING MATERIAL

• CARBOHYDRATES EXIST IN A RATIO OF:

1 CARBON: 2 HYDROGEN: 1 OXYGEN• MONOSACCHARIDES ARE THE

MONOMERS EX. GLUCOSE, FRUCTOSE,

GALACTOSE• POLYSACCHARIDES ARE THE

POLYMERS EX. STARCH, CELLULOSE,

GLYCOGEN

TWO FUNCTIONS OF POLYSACCHARIDES

• ENERGY STORAGE

STARCH IN PLANTS, GLYCOGEN IN ANIMALS

• STRUCTURAL SUPPORT

CELLULOSE IN PLANT CELL WALLS, CHITIN FOUND IN EXOSKELETONS

CONCEPT 5.3• LIPIDS ARE A DIVERSE GROUP OF

HYDROPHOBIC MOLECULES• LIPIDS ARE HYDROPHOBIC• MADE UP OF 3 F.A. AND A GLYCEROL• FATTY ACIDS INCLUDE

HYDROCARBON CHAINS OF VARIOUS LENGTHS. THEY ARE NONPOLAR AND THEREFORE HYDROPHOBIC.

SATURATED F.A.• HAVE NO DOUBLE BONDS BETWEEN

CARBONS• TEND TO PACK SOLIDLY AT ROOM

TEMPERATURE• ARE LINKED TO HEART DISEASE• ARE COMMONLY PRODUCED BY

ANIMALS• EX. BUTTER

UNSATURATED F.A.• HAVE SOME C=C RESULTING IN KINKS• TEND TO BE LIQUID AT ROOM

TEMPERATURE• ARE COMMONLY PRODUCED BY

PLANTS• EX. CORN OIL AND OLIVE OIL

FUNCTIONS OF FATS• ENERGY STORAGE – YIELDS 9

CAL/GM• PROTECTION OF VITAL ORGANS AND

INSULATION• FAT IS STORED IN ADIPOSE CELLS

PHOSPHOLIPIDS

• MAKE UP CELL MEMBRANE• HAVE A GLYCEROL BACKBONE

(HEAD) THAT IS HYDROPHILIC• HAVE 2 F.A. TAILS THAT ARE

HYDROPHOBIC• ARE ARRANGED IN A BILAYER IN

FORMING THE CELL MEMBRANE• HYDROPHILIC HEADS ON THE

OUTSIDE OF MEMBRANE

STEROIDS• MADE UP OF 4 RINGS THAT ARE

FUSED TOGETHER• CHOLESTEROL IS A STEROID AND IS

A COMMON COMPONENT OF CELL MEMBRANES

• ESTROGEN AND TESTOSTERONE ARE STEROID HORMONES

CONCEPT 5.4• PROTEINS HAVE MANY STRUCTURES,

RESULTING IN A WIDE RANGE OF FUNCTIONS

PROTEINS• POLYMERS MADE UP OF A.A.

MONOMERS• A.A. CONTAIN A CENTRAL CARBON

BONDED TO A CARBOXYL GROUP, AN AMINO GROUP, A HYDROGEN ATOM, AND AN R GROUP (VARIABLE GROUP)

• PEPTIDE BONDS LINK A.A. FORMED BY DEHYDRATION SYNTHESIS

• FUNCTION DEPENDS ON THE ORDER AND NUMBER OF A.A.

4 LEVELS OF PROTEIN STRUCTURE

• PRIMARY – THE UNIQUE SEQUENCE IN WHICH A.A. ARE JOINED

• SECONDARY – REFERS TO ONE OF TWO THREE-DIMENSIONAL SHAPES THAT ARE THE RESULT OF HYDROGEN BONDING

- ALPHA HELIX IS COILED SHAPE - BETA PLEATED SHEET IS AN

ACCORDION SHAPE

4 LEVELS OF PROTEIN STRUCTURE

• TERTIARY – RESULTS IN A COMPLEX GLOBULAR SHAPE, DUE TO INTERACTIONS BETWEEN R-GROUPS, VAN DER WAALS INTERACTIONS, HYDROGEN BOND, AND DISULFIDE BRIDGES

• GLOBULAR PROTEINS SUCH AS ENZYMES ARE HELD IN POSITION BY THESE R-GROUP INTERACTIONS

4 LEVELS OF PROTEIN STRUCTURE

• QUATERNARY – REFERS TO THE ASSOCIATION OF TWO OR MORE POLYPEPTIDE CHAIN INTO ONE LARGE PROTEIN

• EX. Hgb - IT IS COMPOSED OF FOUR CHAINS

PROTEIN SHAPE• CRUCIAL TO PROTEIN FUNCTION• WHEN A PROTEIN DOESN’T FOLD

PROPERLY, ITS FUNCTION IS CHANGED

• CAN BE THE RESULT OF A SINGLE A.A. SUBSTITUTION – ABNORMAL Hgb TYPICAL OF SICKLE CELL (A MUTANT ADENINE REPLACES THYMINE AND CREATES VALINE INSTEAD OF GLUTAMIC ACID)

CHAPERONINS• PROTEIN MOLECULES THAT

ASSIST IN THE PROPER FOLDING OF PROTEINS WITHIN CELLS

DENATURATION• OCCURS WHEN A PROTEIN IS

DENATURED WHEN IT

LOSES ITS SHAPE AND

ABILITY TO FUNCTION

DUE TO HEAT, A

CHANGE IN pH,

OR SOME OTHER

DISTURBANCE

CONCEPT 5.5• NUCLEIC ACIDS STORE AND

TRANSMIT HEREDITARY INFORMATION

DNA AND RNA• TWO NUCLEIC ACIDS• MONOMERS ARE

NUCLEOTIDES MADE UP OF

- NITROGENOUS BASES (A, T, G, C, U)

- PENTOSE (5 CARBON) SUGAR

- PHOSPHATE GROUP

DNA• MOLECULE OF HEREDITY• IS A DOUBLE-STRANDED HELIX• A, T, G, C• ADENINE NUCLEOTIDES WILL

HYDROGEN BOND TO THYMINE NUCLEOTIDES, AND CYTOSINE TO GUANINE

RNA• SINGLE-STRANDED• A, U, G, C• IMPORTANT IN

PROTEIN SYNTHESIS