Organic Chemistry Presentation v 1.0.notebook

Organic_Chemistry_Presentation_v_1.0.notebook

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June 02, 2014

Organic Chemistry

Carbon and the Molecular Diversity of Life

• Carbon is the backbone of biological molecule• Organic chemistry is the chemistry of carbon compounds.• Carbon has the ability to form long chains.• Without this property, large biomolecules such as proteins, lipids, carbohydrates, and nucleic acids could not form.

Organic Chemistry

Organic chemistry is the study of carbon compounds

• Organic compounds range from simple molecules to colossal ones• Most organic compounds contain hydrogen atoms in addition to carbon atoms• Vitalism, the idea that organic compounds arise only in organisms, was disproved when chemists synthesized the compounds• Mechanism is the view that all natural phenomena are governed by physical and chemical laws

Organic Chemistry

• Carbon has four valence electrons to make covalent bonds• Carbon atoms can form diverse molecules by bonding to four other atoms• Electron configuration is the key to an atom’s characteristics• Electron configuration determines the kinds and number of bonds an atom will form with other atoms

Organic Chemistry

1 Organic chemistry is a science based on the study of A functional groups.

B vital forces interacting with matter.C carbon compounds.

D water and its interaction with other kinds of molecules.

E inorganic compounds.

2 Which property of the carbon atom gives it compatibility with a greater number of different elements than any other type of atom?

A Carbon has 6 to 8 neutrons.

B Carbon has a valence of 4.

C Carbon forms ionic bonds.D A and C only

E A, B, and C


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What type(s) of bond(s) does carbon have a tendency to form?

ionichydrogencovalentA and B onlyA, B, and C

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A

B C

D E

4 How many electron pairs does carbon share in order to complete its valence shell?

A 1

B 2

C 3

D 4

E 8

• Compounds made up of carbon and hydrogen atoms

• Aliphatic and Aromatic• Aliphatic hydrocarbons: compounds with carbon atoms connected in a straight chain• Aromatic hydrocarbons: compounds with carbon atoms connected to form cyclic structure

• Aliphatic compounds consist of three classes of compounds:AlkanesAlkenesAlkynes

Hydrocarbons

• Hydrocarbon chains where all the bonds between carbons are SINGLE bonds• They are also known as saturated hydrocarbons.• They are “saturated” with hydrogens.• Name uses the ending ane• Examples: Methane, Propane, Butane, Octane

Alkanes

Aliphatic hydrocarbons

The general formula CnH2n+2 n = number of carbon atoms

Alkanes

Hexane

Heptane

Octane

Nonane

Decane

CH4 Methane

C2H6 Ethane

C3H8 Propane

C4H10 Butane

C5H12 Pentane

Alkanes

• Straight chain alkanes: An alkane that has all its carbons connected in a row.

CH3CH2CH3

• Branched chain alkanes: An alkane that has a branching connection of carbons.

CH3CHCH2CH3

CH3


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AlkanesAlkanes

Hydrocarbons are non polar

Alkanes

What is the reason why hydrocarbons are not soluble in water?

The majority of their bonds are polar covalent carbon to hydrogen linkages.The majority of their bonds are nonpolar covalent carbontohydrogen linkages.They are hydrophilic.They exhibit considerable molecular complexity and diversity.They are lighter than water.

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A

B

C D

E

• Primary carbon (1o)• a carbon bonded to one other carbon

• Secondary carbon (2o)• a carbon bonded to two other carbons

• Tertiary carbon (3o)• a carbon bonded to three other carbons

Alkanes AlkenesAlkens have atleast one 1 double bond between two carbon atoms.General formula: CnH2nThe name uses the ending ene

The first member would be C2H4 Ethene ( from 2 carbon parent, ethane) C3H6 Propene

Naming should give least number to the double bonded carbon.

CH2=CHCH2CH3 1butene ( number 1 indicates the double bond is on the first Carbon atom)

CH2=CHCH=CH2 1,3 butadiene ( there are two double bonds) so the name ends with "diene"

1 2 3 4

1 2 3 4


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AlkeneAlkyne general formula: CnH2n2

They must have at least one triple bondThe name uses the ending yne

C2H2 Ethyne or commonly known as acetylene

C3H4 Propyne or propylene

Alkynes

Ball and stickmodel

Space fillingmodel

Molecular formula

Structuralformula

Aliphatic hydrocarbons Cycloalkanes

• Carbon can also form ringed structures.• Five and sixmembered rings are most stable.• They can take on conformations in which their bond angles are very close to the tetrahedral angle.• Smaller rings are quite strained

Aromatic hydrocarbonsThey have benzene ring structure ( hexagon) and have particular aroma associated with it.

CH3

BenzeneToluene ( methyl benzene)

6 Hydrocarbons

A are polar.

B are held together by ionic bonds.C contain nitrogen.

D contain only hydrogen and carbon atoms.

E are held together by hydrogen bonds.


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• Hydrocarbons exhibit a phenomenon called isomerism, existence of different molecular arrangement but same formula

• Isomers are compounds with the same molecular formula but different structures and properties:

• Structural isomers have different covalent arrangements of their atoms

• Geometric isomers have the same covalent arrangements but differ in spatial arrangements

• Enantiomers are isomers that are mirror images of each other

Isomers

http://media.pearsoncmg.com/bc/bc_campbell_biology_7/media/interactivemedia/activities/load.html?4&B

cis isomer: The two CH3 are on the same side.

trans isomer: The two CH3 are on opposite sides.

Enantiomers differ in spatial arrangement around an asymmetric carbon, resulting in molecules that are mirror images, like left and right hands. The two isomers are designated the L and D isomers from the Latin for left and right (levo and dextro). Enantiomers cannot be superimposed on each other.

enantiomers are isomers that are nonsuperimposable mirror images

geometric isomers

structural isomers

Isomers

7 Structural isomers are molecules that

A are enantiomers.

B are hydrocarbons.

C have a ring structure.

D are mirror images.

E differ in the covalent arrangements of their atoms.

Which of the following is true of geometric isomers?

They have variations in arrangement around a double bond.They have an asymmetric carbon that makes them mirror images.They have the same chemical properties.They have different molecular formulas.Their atoms and bonds are arranged in different sequences

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A

B

C

D

E

9 The two molecules shown in Figure 4.1 are best described as

A optical isomers.

B radioactive isotopes.

C structural isomers.

D nonradioactive isotopes.

E geometric isomers.

10 Which of the following is true of geometric isomers?

A They have variations in arrangement around a double bond.

B They have an asymmetric carbon that makes them mirror images.

C They have the same chemical properties.

D They have different molecular formulas.

E Their atoms and bonds are arranged in different sequences.

http://media.pearsoncmg.com/bc/bc_campbell_biology_7/media/interactivemedia/activities/load.html?4&b


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June 02, 2014

Functional groups

Haloalkanes/alkenes/alkynesAlcohols / Thiols AcidsAminesKetonesAldehydesEstersEther

• A group or an atom that imparts special physical and chemical properties to the compound• Based on the functional group, the compounds are classified as follows.

Halo alkanes/alkenes/alkynes

Presence of a Halogen atom ( F, Cl or Br)

CH3Cl, CH2Cl2 , CHCl3, CCl4, F2C=CF2 , FC = CF

They are formed when one or more H atoms are replaced by halogen atom/s

Alcohols and Thiols

The functional group is a hydroxyl group, OHFor thiols it is SHThiol is the same as sulfhydride

In CH4, one H is replaced by OH

The name ends with ol, drop the alkane "e" add "ol"

CH3OH methane becomes methyl alcohol or Methanol

CH3CH2OH ethyl alcohol or ethanol

11 A compound contains hydroxyl groups as its predominant functional group. Which of the following statements is true concerning this compound?

A It lacks an asymmetric carbon, and it is probably a fat or lipid.

B It should dissolve in water.

C It should dissolve in a nonpolar solvent.

D It won't form hydrogen bonds with water.

E It is hydrophobic.

Acids or Carboxylic acidsThe functional group is COOH

Replace one H atom in the alkane by a COOH group

HCOOH Methanoic acid or formic acidCH3COOH = Ethanoic acid or acetic acid or vinegar

CH3CH2COOH = Propanoic acid

Drop the "e" from the parent alkane and add "oic acid"

COOH COOH

ethane dicarboxylic acid or oxalic acid

AminesThe functional group is NH2

CH3NH2, replace one H by an NH2 group

CH3NH2 Amino methane or Methyl amine

More than one functional groups, same or different are common in organic compoundsexample: amino acids. They have amine and acid groups


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What is the name of the functional group shown in the following figure?

carbonyl ketone aldehyde carboxyl hydroxyl

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A B

C

D E

Which two functional groups are always found in amino acids?

ketone and aldehydecarbonyl and carboxylcarboxyl and aminophosphate and sulfhydrylhydroxyl and aldehyde

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A

B

C

D E

Ketones

The functional group is C=O or "carbonyl" groupUsually sandwiched between two carbon groups

CH3CH2CH3 = propaneCH3CO CH3 propanone or acetone ( nail polish remover)Drop e and add none

H3C C CH3

CH3COC2H5 Ethyl methyl ketone or butanone

O

A function the functional group can make!

AldehydesThe functional group is CHO

drop 'e' of the parent alkane and add 'nal'

HCHO (1 carbon) Methanal or Formaldehyde

CH3CHO (2 carbon) Ethanal or Acetaldehyde

The way the carbonyl group is bonded to the main body of the molecule is different in acids, ketones and aldehydes

Ester

Esters are formed by the combination of an acid and an alcohol by eliminating one molecule of water. They are usually pleasant smelling compounds ( natural oils and essence)The functional group is COOR where R could be another alkyl group

CH3COOH + CH3OH > CH3COOCH3

CH3COOCH3named as methyl acetate

CH3COOC2H5 ethyl acetate

C2H5COOCH3 methyl propanoate


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EtherThe functional group is O sandwiched between two carbon groups

CH3O CH3 dimethyl ether

They are highly flammable and used as solvents in organic synthesis

Groups with a Carbon–Oxygen Double Bond (Carbonyl Groups)

AmidesAmides are formed by the reaction of carboxylic acids with amines.

RCOOH + H2NR' > H2O

CONH linkage is known as the amide linkage ( peptide) in proteinsThis linkage is formed when several amino acids join with their acid and amino groups together.

14 Which is the best description of a carbonyl group?

A an oxygen joined to a carbon by a single covalent bond

B a nitrogen and two hydrogens joined to a carbon by covalent bonds

C a carbon joined to two hydrogens by single covalent bonds

D a sulfur and a hydrogen joined to a carbon by covalent bonds

E a carbon atom joined to an oxygen by a double covalent bond

15 What is the name of the functional group shown in Figure 4.4?

A carbonyl

B ketone

C aldehyde

D carboxyl

E hydroxyl

16 Which of the following contains nitrogen in addition to carbon, oxygen, and hydrogen?

A an alcohol such as ethanol

B a monosaccharide such as glucoseC a steroid such as testosterone

D an amino acid such as glycine

E a hydrocarbon such as benzene


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17 Which molecule contains a sulfhydryl( thiol) functional group?

Macromolecules• large molecules composed of smaller molecules• Are complex in their structures• Carbon has the unique property of joining together via covalent bonding to form large ( macro) molecules • Most macromolecules are polymers, built from monomers• Three of the classes of life’s organic molecules are polymers

• Proteins• Carbohydrates• Nucleic acids

The Synthesis and Breakdown of Polymers

• Monomers form larger molecules by condensation reactions called dehydration reactions

Polymer• Is a long molecule consisting of many similar building blocks called monomers

longer polymer

Monomershort polymer

• Although organisms share the same limited number of monomer types, each organism is unique based on the arrangement of monomers into polymers• An immense variety of polymers can be built from a small set of monomers

Polymers

Amino Acids and Proteins

proteins are formed when several amino acids combine togetheracid end and amine end join together to form long peptide chain

peptide chain

Carbohydrates/sugarsSimple sugars are polyhydroxy aldehydes or ketones.Table sugar, (sucrose) is made up of glucose and fructose.


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• In solution, they form cyclic structures.• These can form chains of sugars that form structural molecules such as starch and cellulose.• Not all sugars are sweet.

carbohydrates/sugars Nucleic AcidsNucleic acids are made up of a sugar and a base (nitrogen compound)Two of the building blocks of RNA and DNA are sugars (ribose or deoxyribose) and cyclic bases (adenine, guanine, cytosine, and thymine or uracil)

sugars

bases

Nucleic Acids

RNA or DNA + Base + PO43 = nucleotide

a nucleotide

A nucleotide is made up of 3 components:

a 5carbon sugar (ribose or deoxyribose) + a nitrogenous base + a phosphate group, PO4

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Nucleotides combine to form the familiar doublehelix form of the nucleic acids

The blue ribbon is the nucleotide chainThey join together via hydrogen bonding through the bases

18 Which of the following is not one of the four major groups of macromolecules found in living organisms?

A glucose

B carbohydrates

C lipids

D proteins

E nucleic acids

19 Polymers of polysaccharides, fats, and proteins are all synthesized from monomers by which process?

A connecting monosaccharides together (condensation reactions)

B the addition of water to each monomer (hydrolysis)

C the removal of water (dehydration reactions)

D ionic bonding of the monomers

E the formation of disulfide bridges between monomers


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Other complex molecules of life

• Fats and Lipids

• Are a diverse group of hydrophobic molecules• Are the one class of large biological molecules that do not consist of polymers• Share the common trait of being hydrophobic

• Fats• Are constructed from two types of smaller molecules, a single glycerol and usually three fatty acids• Fatty acids:• Carboxylic acids with a very long chain of carbon atoms.• Vary in the length and number and locations of double bonds they contain


a fatty acid

CH2OH

CH2OH

CH2OH

glycerol


attachment of fatty acids to glycerol


3 fatty acids added to glycerol producing a fat molecule

• Saturated fatty acids• Have the maximum number of hydrogen atoms possible• Have no double bonds in their carbon chain

(a) Saturated fat and fatty acid

Stearic acid

Figure 5.12

Lipids and Fats

• Unsaturated fatty acids• Have one or more double bonds• When hydrogenated ( add more Hydrogen) they become solid and saturated

(b) Unsaturated fat and fatty acidcis double bondcauses bending

Oleic acid

Figure 5.12

Other complex molecules of lifePhospholipids

• Phospholipids• Have only two fatty acids• Have a phosphate group instead of a third • fatty acid• Results in a bilayer arrangement found in cell membranes



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• Steroids• Are lipids characterized by a carbon skeleton consisting of four fused rings


cholesterol

20 Which of the following is (are) true for the class of large biological molecules known as lipids?

A They are insoluble in water.

B They are an important constituent of cell membranes.

CThey contain twice as much energy as an equivalent weight of polysaccharide.

D Only A and B are correct.

E A, B, and C are correct.

21 Saturated fatty acids

A are the predominant fatty acid in corn oil.

B have double bonds between carbon atoms of the fatty acids.

Chave a higher ratio of hydrogen to carbon than do unsaturated fatty acids.

D are usually liquid at room temperature.

E are usually produced by plants.

22 The hydrogenation of vegetable oil would result in which of the following?

Aa decrease in the number of carboncarbon double bonds in the oil (fat) molecules

Ban increase in the number of hydrogen atoms in the oil (fat) molecule

C the oil (fat) being a solid at room temperature

D A and C only

E A, B, and C

Organic Chemistry Presentation v 1.0.notebook

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