MACROMOLECULES

• Macromolecules (1000’s of atoms and weigh over 100,000 daltons)

• 4 Kinds of macromolecules: Carbohydrates, lipids, proteins, and nucleic acids (know this in your sleep!)

MACROMOLECULES ARE:

POLYMERS: chainlike molecules made up of -

MONOMERS: (the repeated units)

Diversity of Polymers – different sequences of the basic 40-50 monomers

How do monomers make polymers? Condensation /Dehydration

reaction: One monomer provides

an ‘–OH’ and the other provides a ‘-H’ and together these form H2O

H2O is REMOVED; Covalent bond is formed between MONOMERS = Polymers are made!

Needs ATP and Enzymes Anabolic/biosynthesis reactions use

this to make macromolecules for growth/replacement

How do polymers break up?

Hydrolysis Reaction: Covalent Bond is broken; H2O

is added across the broken bond

Polymers make Monomers Provides ATP and Uses

Enzymes Used for digestion, cell

respiration

I) Sugars are all - Carbohydrates

Monomer Unit of Carbohydrates called: Monosaccharides

Polymer called PolysaccharideGeneral formula: [CH2O]n

– For example, glucose has the formula C6H12O6.

– Most names for sugars end in -ose.

FRUCTOSE (from FRUIT!!)

LACTOSE (from MILK)

MALTOSE (from ‘Malt’ – a fermentation product)

SUCROSE (from cane sugar)

DEXTROSE (=glucose)

Monosaccharide Classification Overview:

1) Based on Aldehyde or Ketone Functional group (aldose/ketose)

2) Number of Carbon atoms (pentose, hexose…)3) Arrangement of Carbon Atoms - Isomers4) Straight chain or ring structure

- Know how to identify a simple sugar/monosachcharide by sight as a ring structure and a straight chain structure

- Know the glycosidic linkage is represented as an -O- when 2 monosachcharides are connected

Monosaccharide Classification

1) Based on Functional Group:

• KETOSE = Ketone function group (C=O)

• ALDOSE = Aldehyde functional group

(-CHO)

FRUCTOSE GLUCOSE

Monosaccharide Classification

2) Based on Number of Carbons:

HEXOSE = 6 C PENTOSE = 5 C TRIOSE = 3C

GLUCOSE (6)RIBOSE (5)

Monosaccharide Classification

3) Based on Arrangement of Carbon Atoms:

Enantiomers: Isomers (Glucose and Galactose)

No test ques. on this for your level!

Monosaccharide Classification4) Based on Ring Structure : Linear monomers form rings in solutions (Alpha and Beta Rings – based on plane of –OH -skip details)

Monosaccharide to Disaccharide(dehydration reaction)

Glucose Fructose+ = Sucrose

Glucose + Galactose = Lactose

Glucose + Glucose = Maltose

- Important Disaccharides (Sucrose – table sugar, Lactose – Milk, Maltose – Beer)

Monosaccharide to Disaccharide A Glucose monomer and a fructose monomer can be joined using a GLYCOSIDIC LINKAGE to form

SUCROSE (know to identify this link) SUCROSE is a DISACCHARIDE

Glucose

FructoseSUCROSE

Monosaccharide to Disaccharide A Glucose monomer and a fructose monomer can be joined using a GLYCOSIDIC LINKAGE to form

SUCROSE SUCROSE (table sugar) is a DISACCHARIDE

Glucose

FructoseSUCROSE

Monosaccharide to Polysaccharide

G G+

= Polysaccharide

G + G+

- 1000’s of monosaccharides join up to form POLYSACCHARIDES

+ ………………

Carbohydrate ReviewMonosacharrides Disacharrides

(glucose, fructose) (sucrose, lactose)

Condensation/dehydration reaction

Polysacharrides

Structural Storage

Cellulose Starch (Plant)

Chitin Glycogen (Animals)+ +

a) Storage Polysaccharides

1) STARCH (in potatoes – ‘stored NRG’ in plants)

MONOMER is Glucose

Links up to form starch many, many glucose molecs)

a) Storage Polysaccharides

1) STARCH has 2 polymers: (skip details)

1-4 linkage of Glucose Monomers (amylose -helical)

1-6 linkages causes branching (amylopectin)

a) Storage Polysaccharides

2) GLYCOGEN

(in animals – ‘stored ATP’ in muscle and liver)

MONOMERS – Glucose

b) Structural Polysaccharides

1) CELLULOSE

(in plant cell wall)

Monomers-Glucose

1-4 linkage

b) Structural Polysaccharides

2) CHITIN

(in exoskeleton of arthropods)

Monomers-Glucose

Glucose has a ‘-N group’ attached

Starch Test – Lugol’s Iodine

                                  

Benedict’s Test

• Will be positive for Reducing Sugars (monosaccharides, disaccharides except sucrose)

Benedict’s Test

• CuSO4 Cu++ + SO4

--

  • 2 Cu++  +  Reducing

Sugar Cu+         (electron donor)

• Cu+ Cu2O

II) Lipids

Lipids – are hydrophobic

(mostly hydrocarbons) They are NOT polymers Important classes: FATS,

PHOSPHOLIPIDS, and STEROIDS

FATS

Fats– are triglycerides - have glycerol and fattyacids linked up by an ‘ester’ bond

Glycerol is a 3C alcohol

Fatty acid is RCOOH and can have long hydrophobic C-H chains- these can have double bonds or single bonds or a mixture

                             

  

Saturated fats - solids at room temp. - have all Carbons SATURATED - that means every carbon has max. number of hydrogen attached Ex. butterUnsaturated fats - liquid at room temp. - have some Carbons UNSATURATED - that means DOUBLE BONDS from some carbons having less than max. number of hydrogen attached Ex. Oil. DOUBLE BONDS = freedom of movement!

CARCINOGENIC

Percent Fatty Acid Present in Triglycerides

 Fat or Oil Saturated Unsaturated

 Palmitic Stearic  Oleic Linoleic  Other

Animal Origin

 Butter 29 9 27 4 31

 Lard 30 18 41 6 5

 Beef 32 25 38 3 2

 Vegetable Origin

 Corn oil  10 4 34 48 4

 Soybean 7 3 25 56 9

 Peanut 7 5 60 21 7

 Olive 6 4 83 7 -

Artherosclerosis-plaque in artery

Fat Substitutes

• Olestra - sucrose (sugar) with fatty acids (No digestion!!)

• Hydrogenated Vegetable Oils: Peanut Butter, Shortening, Margarine

                    

                   

Fat Functions                     

                   

• Energy Storage (1 gm of fat = 2 gm starch; fat- 4 cal/gm)

• Plants use starch to store energy (bulky); seeds have oil

• Animals – store energy as fat• Insulation; Protect vital organs• Absorption of Vitamins K, E,

D, A

Phospholipids                     

                   

• Two fatty acids attached to glycerol and a phosphate group at the third position

• Phosphate Group is –ve

• R – fatty acid hydrocarbon chain

• X – other groups

• Fatty acids (hydrophobic)+ glycerol+ phosphate group +polar group (hydrophilic)

• The fatty acid tails are hydrophobic, but the phosphate group and its attachments form a hydrophilic head

• -know to recognize it!

Steroids                     

                   

• Consist of 4 fused rings

• Cholesterol, sex hormones

• Vary in functional groups

Lipid Test

• Brown paper turns translucent with lipid (grease test)

• Sudan IV Test:

Proteins                     

                   

• Proteios – first place!!

• Polymers made up of Amino Acid Monomers

Amino Acids                     

                   

• Have Carboxyl (COOH) and amino groups (NH2)

• Center – Alpha Carbon

• ‘R’ – 20 different possibilities = 20 amino acids

• Ionized at neutral pH inside the cell (COO- and NH3

+)

Amino Acids                     

                   

• Hydrophobic ‘R’ groups

Amino Acids                     

                   

• Hydrophilic Polar ‘R’ groups

Amino Acids                     

                   

• Electrically charged ‘R’ groups (Acidic/ Basic; also hydrophilic)

Amino Acids                     

                   

• Peptide Bond Formation: (O=C-NH) Dehydration reaction linking amino acid monomers into a polypeptide chain- know this bond!

Amino Acids                     

                   

• Primary Structure: Sequence of amino acid chain - is it Val-His-Leu… or Val-Glu-Leu….

• Change in Primary Structure can cause protein to function abnormally (DUH!)

Amino Acids                     

                   

• Secondary Structure: Result of H Bonding between O=C and N-H (atoms in this secondary structure are in the polypeptide backbone)

Helix (coils) – every 4th aa linked Pleated Sheets (folds)

Lysozyme

Helix

Pleated Sheets

Amino Acids                     

                   

• Tertiary Structure: Result of H Bonding between side chain ‘R’ groups H bonds among polar and/or

charged groups; ionic bonds between charged

R groups, and hydrophobic interactions

and van der Waals interactions among hydrophobic Rgroups

Disulfide Bridges (know this is important in tertiary structure!)

Amino Acids                     

                   

• Quarternary Structure: Result of noncovalent interactions between polypeptide chainsDimers, Trimers,

Tetramers – aggregations of many polypeptide subunits

Why is folding important?                     

                   

“Diseased prions induce healthy prion proteins to change their shape, and clusters of disease build, leaving holes in the brain.” – SF Chronicle

Denaturation                     

                   

• Protein Denaturation – Loss of biological activity• Loss of Native Confirmation/folding due to changes in pH, salt concentration, temperature • Protein can come back to original confirmation (Renatured)

Chaperonins                     

                   

• The folding of many proteins is protected in cells by chaperonin proteins that shield out bad influences.

Biuret Test

• Biuret Reagent has CuSO4 and KOH

• Blue-violet = proteins• Purple/pink = peptides• Will not detect free amino

acids

• Amino Acid Sequence of a Polypeptide is coded by a GENE

• A gene is a specific sequence of DNA

• DNA is made of Nucleic Acids

Nucleic Acids

• GENE codes for a messenger RNA in the nucleus

• mRNA is translated in the cytoplasm

• Protein is synthesized using the mRNA

Nucleic Acids

Nucleic Acids

• DNA and RNA are Nucleic Acids

• Nucleic Acids are Polymers

• The monomers are called NUCLEOTIDES

Nucleotides

• NUCLEOTIDES are made of:

• Pentose Sugar• Nitrogen Base• Phosphate group

Nucleotides- Nitrogen Base

• Nitrogen Base can be of 2 types:

• Purine – 2 rings; Adenine and Guanine

• Pyrimidine – 1 ring; Cytosine, Uracil, and Thymine

Nucleotides- Nitrogen Base

• Purines and Pyrimidines bond with each other

• A can form a bond with T or U

• G can form a bond with C

Nucleotides-Sugar

• Pentose Sugar is Ribose• DNA has Deoxy Ribose• RNA has Ribose

Nucleosides-No Phosphate group

• Pentose Sugar + Nitrogen Base

Nucleotides

• Pentose Sugar + Nitrogen Base + Phosphate

Nucleotides join together to make Nucleic Acids

Sugar – Phosphate backbone

DNA is a double helix – 2 strands are complementary

1953

DNA Spooling