Organic MoleculesBiochemistry

Organic Molecule

• Is a hydrocarbon• Carbon bonds to

hydrogen• Simplest hydrocarbon

is when 4 hydrogen atoms bond to one carbon (methane)

• CH4

A Little Less Simple• Carbon binds to other

carbon atoms• This is the uniqueness

of carbon: it can bind to itself

• Ethane is C2H6

A Little More Less Simple

• Carbon likes to form long chains

• Pentane: 5 carbons• C5H12

A Little More Complicated

• Branched chains• Isohexane• C6H14

A Lot More Complicated

• Form rings• C6H12

• Cyclohexane

Even More Complicated

• Carbon-Carbon single bonds

• Carbon-Carbon double bonds

• Carbon-Carbon triple bonds

• As you increase the number of bonds between carbons, the number of hydrogen atoms decreases

How many single vs double bonds?

• Determines saturated or unsaturated

• Have special names• Saturated has only

single bonds—every carbon is bonded singly to another carbon and hydrogen occupies every other spotThese are Alkanes

Alkenes

• Unsaturated• Contain one or more

double bonds between carbon atoms

• Not EVERY possible spot is occupied by a hydrogen

Alkynes

• Contain a triple bond• Fewer hydrogen atoms

Ethyne

Living Things

• Simple hydrocarbons not common in living organisms

• They form the building blocks of more complex organic molecules that make up living organisms

Four CategoriesBased on function

• Carbohydrates

• Lipids

• Proteins

• Nucleic Acids

All four have in common…

• Carbon backbone

• Other atoms, usually H,O,N,P,and/or S

• These atoms form functional groups, which we can recognize

• These groups replace the H that would be in a typical hydrocarbon

In common…

• all form by dehydration synthesis

• This means single units (monomers) join together; water is removed to join them

• No polymers in lipids• Enzyme catalyzed

Dehydration Synthesis

Functional groups give characteristics

• Attaching the functional groups to the carbon backbone gives the chemical characteristics of the organic molecule

• Methane gas vs. methanol liquid

Methanol

Functional groups

• Formaldehyde has a strong odor, highly reactive

• Formic Acid, only slightly different—why an acid?

Hydrocarbons

• Only have H attached to carbon backbone

• Do not break easily• Very stable

CarbohydratesSugars and Starches

#1 Energy Source (quick)

Characteristic of Carbohydrates

• A 2 to 1 ratios of Hydrogen to Oxygen

• C6H12O6

• The basic monomer (or building block) is the monosaccharide

Building Chains

• Two monosaccharides is a disaccharide

• Many is a polysaccharide

• A few is an oligosaccharide

• The simple chains are sugars

• The longer chains are starches

Starches

Sugars

• Consists of three or more C atoms with either an aldehyde or a ketone group

• And at least 2 OH groups

• Formed by dehydration synthesis

Simple Sugars

• Like to form ring formations

• Glucose, galactose, fructose all have the same molecular formula

• Different arrangements

Starch: the main polysaccharide

• Other polysaccharides include glycogen (storage in animals)

• Cellulose (plant material

• Pectin (plant material)• Starch (storage in

plants)

Lipids

Characteristics

• Do not dissolve in water

• Hydrophobic

• Greasy or oily

• Energy Storage

• Structural components (esp membranes)

• Cannot polymerize

Energy Efficient

• Number one method of energy storage

• Long term• Can store twice as

much energy as carbohydrates

• Due to high number of C-H bonds—very energy efficient

Common Types

• Triglycerides: one glycerol and three fatty acids (70 types)

• Fat is solid at room temperature (saturated)

• Oils are liquid (unsaturated)

Saturated vs Unsaturated

• Saturated: contains a H at every possible location on the fatty acids

• Unsaturated: contains one or more double bonds

Saturated

Phospholipids

• Split personality

• A glycerol and two fatty acids

• A phosphate group takes the place of the third fatty acid

• Glycerol is hydrophobic

• Phosphate is hydrophyllic

Phospholipids

Phospholipids

Sterols (Steroids)

• No fatty acid tails• All have backbone of

4 fused carbon rings with functional groups

• Hormones and cholesterol are in this group

Testosterone

Waxes

• Fatty acids linked to a long chain with alcohol

• Hydrophobic• Waterproof covering

for insects, leaves, skin on fruit

Proteins

Proteins

• Most diverse group• Many functions• Shape determines

function• Functions include:

structural, hormones, enzymes

• Monomer is the amino acid

Each amino acid has

• One carbon with 4 groups attached

• The 4 groups are: amine group NH2

• Carboxyl group COOH

• Hydrogen• R group—varies with

each amino acid

Amino Acids

• The R group is what gives each amino acid its physical and chemical properties

• It does this by shape and the fact that the R group can be polar or nonpolar; acidic or basic

Making protein chains

• The more amino acids in the chain, the more complex the protein

• The amine group from one joins to the carboxyl end of the other

• This is known as a peptide bond

Protein Structure

Proteins have a 3D shape

Four factors contribute to the shape: primary structure, secondary structure, tertiary structure, and quaternary structure

Primary Structure

• This is the amino acid sequence.

• There are 20 different amino acids

• Which ones, and in what order, determines the primary structure

Secondary Structure

• Strand folds or coils• Caused by hydrogen

bonds between non adjacent amino acids

Tertiary Structure

• Actual 3D shape• Bends and loops into a

glob as R groups react with other R groups

Quaternary Structure

• Two or more polypeptide chains have joined together by numerous weak hydrogen bonds and/or covalent bonds between R groups