1

MacromoleculMacromoleculeses

Molecules of LifeMolecules of Life• MacromoleculesMacromolecules are

large organicorganic molecules molecules which are which are carboncarbon-based-based

• 4 Types:– Carbohydrates– Proteins– Nucleic Acids– Lipids

Carbon can form Carbon can form covalent bondscovalent bonds with as with as many as 4 other atoms.many as 4 other atoms.

PolymersPolymers– Molecules made from repeating units of similar

compounds called MONOMERSMONOMERS – linked together by a series of linked together by a series of covalentcovalent bonds. bonds.– Macromolecules are Macromolecules are POLYMERSPOLYMERS..

Monomers of Monomers of MacromoleculesMacromolecules

Dehydration SynthesisDehydration Synthesis

• Forms polymerspolymers by combining monomersmonomers by ““removing waterremoving water””.

Hydrolysis ReactionHydrolysis Reaction

• Separates monomersmonomers by ““adding wateadding waterr””

Chemical ReactionsChemical Reactions

Hydrolysis Rxn–Bonds broken–Energy Released–Exergonic–Catabolic

Dehydration Synthesis

–Bonds formed–Energy Stored–Endergonic–Anabolic

LetLet’’s Review!!!s Review!!!

A B

How Are How Are Macromolecules Macromolecules

Formed?Formed?

Release Energy or Store Energy?Release Energy or Store Energy?Endergonic or Exergonic?Endergonic or Exergonic?Catabolic or Anabolic?Catabolic or Anabolic?

How are How are Macromolecules Macromolecules

separated or separated or digested?digested?

Release Energy or Store Energy?Release Energy or Store Energy?Endergonic or Exergonic?Endergonic or Exergonic?Catabolic or Anabolic?Catabolic or Anabolic?

CarbohydratesCarbohydrates• General Function:

– Energy storage• Starch (Plants)• Glycogen (Liver)

– Structural Support• Cellulose (Plant Cell Wall)

CarbohydratesCarbohydrates• Compounds Compounds

composed of composed of carbon, hydrogen, carbon, hydrogen, and oxygenand oxygen

– C(1):H(2):O(1) C(1):H(2):O(1) ratioratio• C6H12O6 glucose

• --saccharides– MonosaccharideMonosaccharide– DisaccharideDisaccharide– PolysaccharidePolysaccharide

Carbohydrate Carbohydrate FunctionFunctionPolysaccharide:Polysaccharide: many sugar units many sugar units

Anatomy ApplicationAnatomy Application

• Why Carb Load?• Glycogen stored primarily in liver and

skeletal muscles.

LipidsLipids• Functions:

– ENERGY STORAGE– MAKING CELL MEMBRANES– STEROIDS

LipidsLipids• General term for compounds which are not not

solublesoluble in water in water.– NonPolar/HydrophobicNonPolar/Hydrophobic

• Examples:Examples:– FatsFats– OilsOils– WaxesWaxes– PhospholipidsPhospholipids– Steroid & CholesterolSteroid & Cholesterol– TriglycerideTriglyceride

Fat storage for energy

Building Blocks of Building Blocks of LipidsLipids• Fatty Acids

– Saturated or Unsaturated

• Glycerol

TRIGLYCERIDE

PhospholipidsPhospholipids• Responsible for the structure and function of

the cell membrane.• http://telstar.ote.cmu.edu/biology/downloads/membranes/

index.html

Where do we find these?Where do we find these?

SteroidsSteroids• Class of lipids characterized by a carbon skeleton

consisting of four fused rings

Saturated vs Saturated vs UnsaturatedUnsaturated

SATURATED UNSATURATED (cis) UNSATURATED (trans)

COMPLETELY FULL OF HYDROGEN

NOT FULL OF HYDROGEN CHEM. PROCESS TO ADD IN MORE HYDROGEN “HYDROGENATED”

ALL SINGLE BONDS IN F.A DOUBLE BONDS IN F.A. DOUBLE BONDS IN F.A.

STRAIGHT TAIL BENT TAIL STRAIGHT TAIL

DENSLEY PACKED TAIL LESS DENSLY PACKED TAIL DENSE PACKED

SOLID AT ROOM TEMP LIQUID AT ROOM TEMP SEMI-SOLID AT ROOM TEMP

EX: BUTTER EX: OLIVE OIL EX: CRISCO

Hydrogenated thingsHydrogenated things• What have you heard about hydrogenated and/or

partially hydrogenated things?• Why so bad?• Can be bad: not easily broken down. Accumulates in

your body tissue and arteries• Trans fat video

ProteinsProteinsFUNCTION• Enzymes• Defense• Transportation• Support• Motion• Hormones• storage

Proteins Proteins

• Monomer of Protein = Amino Acid

• Polymer of Protein = polypeptide

Proteins Proteins (Polypeptides)(Polypeptides)

• Building Blocks: AMINO ACIDS– 20 different Amino Acids– Same structure except for R group

• Amino Acids– Carboxylic Acid Group– Amino Group– R group (variable)– Central Carbon

Amino Group

Carboxylic Acid Group

Effect of different R Effect of different R groups:groups:

Nonpolar amino acidsNonpolar amino acids

Why are these nonpolar & hydrophobic?Why are these nonpolar & hydrophobic?

nonpolar & hydrophobic

Effect of different R Effect of different R groups:groups:

Polar amino acidsPolar amino acids polar or charged & hydrophilic

Why are these polar & hydrophillic?Why are these polar & hydrophillic?

ProteinProteinStructureStructure• Shape determines

function in protein structure

• Each level in structure represents a fold in protein

• More folds = more complex protein

Primary Primary structurestructure

• The Amino Acid chain• Sequence of amino acids is

unique for each polypeptide– Slight changes in AA sequence can

result in major differences

What determines the AA sequence?

Changes to primary Changes to primary structurestructure

• Sickle Cell Anemia

hydrophilic

hydrophobic

Secondary structureSecondary structure

• Local folding patterns– α helix– β pleated sheet

• Result of H bonding between backbone N and O.

Secondary structureSecondary structure

Hydrogen Bonding

Tertiary structureTertiary structure• Overall 3D shape of the

polypeptide– Resulting from the interactions of R

groups– Examples:

• Hydrophobic• disulfide bridges (cysteine AA)• hydrogen bonds • ionic bonds

Quaternary structureQuaternary structure• Overall PROTEIN structure

– More than one polypeptide chain bonded together to form a functional protein

Proteins denatureProteins denature• when a protein unravels and loses

its native conformation(shape)– Loss of shape = loss of function– Reversible or Irreversible

Denaturation

Renaturation

Denatured protein

Normal protein

Protein structure Protein structure overviewoverview

1. Primary– AA seq…bonds?

2. Secondary– Alpha or beta…Bonds?

3. Tertiary– bonds?

4. Quaternary– Multiple polypeptides

interact to form functioning protein

FUNCTION• Store Genetic Information• Transmit Genetic Information• “recipe” for Proteins

Two Types:– DNA (deoxyribonucleic acid)– RNA (ribonucleic acid)

Nucleic AcidsNucleic Acids

DNA vs. RNADNA vs. RNA

• Major Differences:– DNA: deoxyribose sugar, ATCG– RNA: ribose sugar, AUCG

Nucleotide Nucleotide StructureStructure• Nucleotides include:Nucleotides include:

1.phosphate group1.phosphate group2.pentose sugar (5-carbon)2.pentose sugar (5-carbon)3.nitrogenous bases:3.nitrogenous bases:

adenine (A)adenine (A)thymine (T) DNA onlythymine (T) DNA onlyuracil (U) RNA onlyuracil (U) RNA onlycytosine (C)cytosine (C)guanine (G)guanine (G)

The only group that changes

NucleotidesNucleotides• Purines: double ring

– Adenine– Guanine

• Pyrimidines: single ring– Thymine– Cytosine

G-C=3 hydrogen bonds A-T=2 hydrogen bonds

Complementary Base Pairing

Phosphodiester LinkagePhosphodiester Linkage• Between Phosphate group of one nucleotide and 3”

OH group of another nucleotide.

ATP…a very special ATP…a very special nucleotide!!nucleotide!!

• Adenosine Triphosphate• Power to drive cellular

reactions• ATP functions by transferring

its phosphate group to another molecule– creating a phosphorylated

intermediate. – phosphorylated intermediate is

usually less stable (more reactive) than the original molecule, which drives the reaction

45