the structure and function of macromolecules. you must know… the role of dehydration synthesis in...
TRANSCRIPT
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