The Big 4

• Carbohydrates• Lipids• Proteins• Nucleic Acids

Um…..What’s up Doc?

Monomers/Polymers

• Monomers: a single unit of a macromolecule

• Polymers: more than one unit of a macromolecule – Linked by covalent bonds

Monomers, Polymers and Macromolecules

CARBOHYDRATES

SUGARSANDSTARCHES

CARBOHYDRATES

Three Types of Carbohydrates

POLYSACCHARIDE(have 3 or more sugar units)

DISACCHARIDES(have 2 sugar units)

MONOSACCHARIDES(have 1 sugar unit)

Structure• Carbohydrates are

composed of carbon (C), hydrogen (H), and oxygen (O) atoms in approximately a 1:2:1 ratio.

MONOSACCHARIDES

Simple Sugars• Simple sugars, made of a single sugar unit.• Examples: Glucose, Galactose, Fructose.• Glucose is the most common simple sugar

Glucose• Glucose, the main sugar in your blood.

• Glucose has 6 carbon atoms, 12 hydrogen atoms, and 6 oxygen atoms.

DISACCHARIDES•Made of two simple sugars or

monosaccharides.•Examples: SUCROSE = Glucose + Fructose (table sugar) MALTOSE = Glucose + Glucose (malt sugar) LACTOSE = Glucose +

Galactose (milk sugar)

POLYSACCHARIDES•Polysaccharides are made of three

or more simple sugars or monosaccharides.

•They usually consist of thousands of connected monosaccharides.

•Examples: starch, cellulose, glycogen.

Complex Carbohydrates Are Often Used to Create Structures

Cellulose is the most abundant macromolecule on earth – and you’re probably wearing it now.

Functions of Carbohydrates

1.Energy source for cells.

2.Provides support for plants.

3.Hard body covering for insects

LIPIDS(FATS)

Characteristics of Lipids

• Lipids are nonpolar organic molecules and, therefore, do not dissolve in water.

Examples

• Examples: bacon fat, vegetable oil, butter, margarine, wax.

Lipids are Hydrophobic Molecules That Exist In Three Primary Forms

Sterol

FatPhospholipid

The Building Blocks of Lipids

GLYCEROL

3

FATTY

ACIDS

Molecular Structure of a Fat

Glycerol• Glycerol is a three-carbon alcohol

molecule usually obtained by the saponification of fats and used as a solvent.

Fatty Acids• Fatty acids are long chains of carbon

atoms with a -COOH group or carboxyl group at the end.

• Examples:

FATTY ACIDS

SATURATED UNSATURATED

Saturated Fatty Acids

• Saturated fatty acids have the maximum possible number of hydrogen atoms (H).

H H H H H H H H H H H O

H C C C C C C C C C C C C OH

H H H H H H H H H H H

Unsaturated Fatty Acids

• Unsaturated fatty acids have double bonds, and therefore fewer hydrogen atoms (H).

H H H H H H H H H H H H H H H H O

H C C C C C C C C C C C C C C C C O H

H H H H H H H H H H H H H H

At a Store Near You

Beginning January 1, 2006, the FDA required that the amount of trans fat be listed on all food labels.

The new line showing levels of trans fat

Solid or Liquid?

• A triglyceride that is solid at room temperature is called FATFAT.

• A triglyceride that is liquid at room temperature is called OILOIL.

Triglycerides• The majority of fat in organisms

consists of one type of polymer of lipids called triglycerides.

• Triglycerides are composed of alcoholalcohol glycerolglycerol and three fatty acidsfatty acids.

Phospholipids• Phospholipids are

made out of

* glycerol,

* 2 fatty acids &

*phosphate group.

• Building block of cell membranes.

Hydrophilic Head Group And Hydrophobic Tails Are The Keys To Phospholipid Function

Phospholipids Form Double-Layered Biological Membranes

Steroids are also Lipids

Note the four ring structure common to all sterols.

Sterols are: 1) essential membrane components and 2) form many hormones.

Sterols As Hormones

Estrogen, testosterone, progesterone, and corticosteriods (cortisol) are all steroid hormones.

Sterols As Hormones

“Designer steroids” are major sporting news where they have been used illegally in track and field, baseball, football and countless other sports.

A heavily muscled Linford Christie who was disqualified from international competition after testing positive for a banned steroid.

Functions of Lipids• Major components of cell membranes.• Insulation.• Protective covering.• Energy storage – fat is stored in animal cells as large lipid droplets.

PROTEINS

Building BlocksSince proteins are LARGE molecules,

they are composed of smaller building blocks – AMINO ACIDSAMINO ACIDS.

•AMINO ACIDS

AMINO ACIDS (AA)There are only 20 different AA

AMINO ACID STRUCTURE

•R group is different in every AA

•Observe different R groups

Models of Amino Acids

CARBON

OXYGEN

HYDROGEN

NITROGEN

PEPTIDE BONDS•Amino acids are joined together by PEPTIDE BONDS.

•Bond forms between the –COOH (carboxyl) group of one AA and the -NH2 of another AA.

H H O H H O H H O H H O

N C C OH + N C C OH N C C N C C+ H2O

H R H R H R R OH

PEPTIDE BOND

How Long Are Proteins?•Proteins are long chains of amino acids with an average of 200 amino acids per chain.

PROTEIN Shapes

HemoglobinHemoglobin – a protein in red blood cells responsible for oxygen transport.

MyoglobinMyoglobin – protein in muscles that serves as storage site for oxygen.

EXAMPLES

TERTIARY STRUCTURE

QUATERNARY STRUCTURE

Functions of Proteins

A. ENERGY SOURCE

B. B. STRUCTURAL COMPONENTSSTRUCTURAL COMPONENTS Following are made out of proteins:

•HAIR

TURTLE

SHELL•SPIDER WEB

•FEATHERS

•NAILS

Strands of the Protein Keratin Create Hair

C. FIGHT INFECTIONS

•FibersFibers in a blood clot and antibodiesantibodies are made out of proteins.

D. ASSIST LIFE PROCESSES•Transports oxygen in red blood cells.

•Aids digestion.

•Enzymes

are proteins.

There are two kinds of nucleic acids, DNA and RNA. •Both are involved in the storage and flow of information from gene to gene product.

DNA

Recently, we’ve learned that RNA also plays important regulatory roles.

Nucleic Acids

Nucleotides Are the Monomers That Create Polymers of DNA and RNA

Nucleotides fuel the cell and coordinate its metabolism.

Nucleotides are Important in Their Own Right

ATP, the cell’s primary energy currency.

Molecules of Life Big Four

Start with water, add lots of small carbon-containing molecules and …….

How do you build a cell?

Use these four major classes of biological molecules.