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Organic Chemistry: Carbon and the Molecular Diversity of Life Slide 2 / 97

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.

Compounds containing only carbon and hydrogen are called hydrocarbons; they are commonly used as a fuel source. Slide 3 / 97

Biological Molecules

Carbon is the backbone of biological molecule.

Carbon has the ability to form long chains.

This property allows the formation of large biomolecules (such as proteins, lipids, carbohydrates, and nucleic acids). Slide 4 / 97

Carbon

Carbon has four valence electrons to make covalent bonds

Carbon atoms can form diverse molecules by bonding to four other atoms

Recall that electron configuration is the key to an atom’s characteristics because it determines the kinds of bonds and number of bonds an atom will form with other atoms Slide 5 / 97

1 Organic chemistry is a science based on the study of ______.

A compounds that can only be made by living cells. B vital forces interacting with matter. C carbon compounds. water and its interaction with other kinds of D molecules. Slide 6 / 97

2 Which property of the carbon atom allows it to bond with many different elements?

A Carbon has 6 to 8 neutrons. B Carbon has 4 valence electrons. C Carbon forms ionic bonds. D A and C only E A, B, and C Slide 7 / 97

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

A 1 B 2 C 3 D 4 E 8 Slide 8 / 97

4 What type/s of bond/s does carbon have a tendency to form?

A Ionic B Hydrogen C Covalent D A and B E A, B and C Slide 9 / 97

Hydrocarbons

Hydrocarbons are compounds made up of carbon and hydrogen atoms

Aliphatic hydrocarbons: compounds with carbon atoms connected in a straight chain

Aliphatic compounds consist of three classes of compounds: Alkanes Alkenes Alkynes

Aromatic hydrocarbons: compounds with carbon atoms connected in cyclic (ringed) structures that have an odor Slide 10 / 97

Aliphatic hydrocarbons: Alkanes

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 Slide 11 / 97 Alkanes Slide 12 / 97 Alkanes

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

CH4 Methane ______Hexane

C2H6 Ethane ______Heptane

C3H8 Propane ______Octane

C4H10 Butane ______Nonane

C5H12 Pentane ______Decane Slide 13 / 97

Straight Chain Alkanes

Straight chain alkanes are alkanes that have all their carbon atoms connected in a row.

These are structural formulas.

CH3-CH2-CH3 This is a condensed formula for propane. Slide 14 / 97 Branched Chain Alkanes

Branched chain alkanes are alkanes that have a branching connection of carbons.

For example, butane has the formula C4H10. Shown below are the straight chain and branched forms of butane.

CH3-CH2-CH2-CH3

Straight chain butane Branched chain butane Slide 15 / 97 Alkanes

Hydrocarbons are non polar, since the difference in electronegativity between C and H is below 0.5. Note that larger molecules are more polarizable and therefore have stronger London dispersion forces which increases boiling point. Slide 16 / 97

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

The majority of their bonds are polar A covalent C-H linkages The majority of their bonds are nonpolar B covalent C-H linkages C They are hydrophilic They exhibit considerable molecular complexity D and diversity E They are lighter than water Slide 17 / 97

6 Gasoline and water do not mix because gasoline is ______.

A less dense than water B less viscous than wtaer C nonpolar and water is polar D volatile and water is not E polar and water is nonpolar Slide 18 / 97

7 Which substance would be the most soluble in gasoline?

A water

B sodium nitrate, NaNO3 C hydochloric acid, HCl

D hexane, C6H14 E sodium chloride, NaCl Slide 19 / 97

Aliphatic hydrocarbons: Alkenes

Alkenes have at least one double bond between two carbon atoms. General formula: CnH2n where n = # of carbon atoms

The name uses the ending -ene.

The simplest alkenes are:

C2H4 Ethene (from 2-carbon parent, ethane)

C H Propene (from 3-carbon parent, propane) 3 6 Ethene Slide 20 / 97 Aliphatic hydrocarbons: Alkynes

Alkynes have at least one triple bond between two carbon atoms. General formula: C H where n = # of carbon atoms n 2n-2 The name uses the ending -yne. The simplest alkynes are:

C2H2 Ethyne (commonly known as acetylene)

C3H4 Propyne or propylene Ethyne Slide 21 / 97

Representing Aliphatic Hydrocarbons

Ball and stick Space filling Structural Molecular model model formula formula Slide 22 / 97

Cycloalkanes

Carbon can also form ringed structures.

Five- and six-membered 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 Slide 23 / 97

Aromatic hydrocarbons

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

CH3

Benzene Toluene ( methyl benzene) Slide 24 / 97

8 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. Slide 25 / 97

9 Hydrocarbons containing only single bonds between the carbon atoms are called ______.

A alkenes

B alkynes

C aromatics

D alkanes

E ketones Slide 26 / 97

10 The general formula of an alkane is ______.

A C2nH2n+2

B CnH2n

C CnH2n+2

D CnH2n-2

E CnHn Slide 27 / 97 Which is the formula of an alkane? 11

A C10H10

B C10H18

C C10H20

D C10H22

E C10H24 Slide 28 / 97

12 The molecular geometry of each carbon aton in an alkane is ______.

A octahedral B sqaure planar C trigonal planar D tetrahedral E trigonal pyramidal Slide 29 / 97

13 Hydrocarbons containing carbon-carbon triple bonds are called______.

A alkenes B alkynes C aromatics D alkanes E ketones Slide 30 / 97 Which is the formula of an alkyne? 14

A C10H10

B C10H18

C C10H20

D C10H22

E C10H24 Slide 31 / 97

An alkene has at least one ______and has the 15 general formula ______.

A C-C single bond, CnH2n+2

B C-C double bond, CnH2n

C C-C triple bond, CnH2n

D C-C double bond, CnH2n-2

E C-C triple bond, CnH2n-2 Slide 32 / 97

16 ______could be the formula of an alkene.

A C3H8

B C3H6

C C6H6

D C17H36

E CH8 Slide 33 / 97

17 Which of the following hydrocarbons has a double bond in its carbon skeleton?

A C3H8

B C2H6

C CH4

D C2H4

E C2H2 Slide 34 / 97

18 The compound below is an ______.

A alkyne B alkene C alkane D aromatic compound E olefin Slide 35 / 97

19 The gasoline consumed by an automobile is a fossil fuel consisting mostly of

A aldehydes B amino acidd C alcohols D hydrocarbons E thiols Slide 36 / 97

Isomers

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.

There are 3 different types of isomers: Structural isomers

click here for an animation Geometric isomers on Isomers

Enantiomers Slide 37 / 97

Structural Isomers

Structural isomers have different covalent arrangements of their atoms.

These three compounds all have the same molecular formula, but differ in which atoms are bonded together. Slide 38 / 97

Geometric Isomers

Geometric isomers must contain a C=C double bond.

Geometric isomers have the same covalent arrangements but differ in spatial arrangements. Geometric isomers are referred to as either cis or trans.

cis isomer trans isomer: The two CH groups are 3 The two CH3 groups are on the same side. on opposite sides. Slide 39 / 97

Enantiomers

Enantiomers are isomers that are mirror images of each other.

Enantiomers cannot be superimposed on each other.

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). Slide 40 / 97

20 Structural isomers are molecules that:

A are enantiomers. B are hydrocarbons. C have a ring structure. D are mirror images. differ in the covalent arrangements of their E atoms. Slide 41 / 97

21 The two molecules shown are best described as

A optical isomers

B radioactive isotopes

C structural isomers

D nonradioactive isotopes

E geometric isomers Slide 42 / 97

22 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 Slide 43 / 97 Functional groups

A functional group is an atom or group of atoms that imparts special physical and chemical properties to the compound

Based on the functional group, the compounds are classified as follows.

Haloalkanes/alkenes/alkynes Alcohols Acids Amines Ketones Aldehydes Esters Ether Slide 44 / 97

Halo- alkanes/alkenes/alkynes

Haloalkanes, haloalkenes, and haloalkynes are characterized by the presence of a halogen atom (F, Cl, Br or I), in place of a hydrogen atom.

CH3Cl, CH2Cl2 , CHCl3, CCl4, CBr4, F2C=CF2 , FC = CF

They are formed when one or more H atoms are replaced by halogen atom/s. Slide 45 / 97

Alcohols

Alcohols contain the functional group -OH (hydroxyl group).

For example, in CH4, one H is replaced by -OH

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

So, methane becomes methyl alcohol or methanol, CH3OH.

CH3CH2OH is called ethyl alcohol or ethanol.

Thiols contain the functional group -SH, (sulfhydryl group) Slide 46 / 97

Naming Alcohols

Alkane Alcohol Alcohol Alkane name formula formula name

CH4 methane CH3OH methanol

C2H6 ethane C2H5OH ethanol

C3H8 propane C3H7OH propanol

C4H10 butane C4H9OH butanol Slide 47 / 97

23 Which of the following statements is true concerning a compound that contains a hydroxyl group?

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. Slide 48 / 97

24 In which of the structures are the atoms bonded ionic bonds?

A A

B B

C C

D C, D, E

E None of the structures Slide 49 / 97 Carboxylic acids

The functional group is -COOH

Replace one H atom in the alkane by a -COOH group

HCOOH = Methanoic acid or formic acid

CH3COOH = Ethanoic acid or acetic acid or vinegar

CH3CH2COOH = Propanoic acid

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

C C C OH Slide 50 / 97

Amines

The 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 compounds example: amino acids. They have amine and acid groups Slide 51 / 97

25 Which of the structures contain(s) a carboxyl group?

A A

B B

C C

D C & E

E None of the structures Slide 52 / 97

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

A carbonyl B ketone C aldehyde D carboxyl E hydroxyl

Slide 53 / 97

27 Which two functional groups are always found in amino acids?

A ketone and aldehyde B carbonyl and carboxyl C carboxyl and amino D phosphate and sulfhydryl E hydroxyl and aldehyde Slide 54 / 97 Ketones

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

CH3CH2CH3 = propane

CH3CO CH3 propanone or acetone ( nail polish remover) Drop e and add none

CH3COC2H5 Ethyl methyl ketone or butanone

O

H3C- C- CH3 Slide 55 / 97 Ketones A function the functional group can make!

Estrogen- has two hydroxyl groups in it.

Testosterone - one hydroxyl group is replaced by a ketone. Slide 56 / 97

Aldehydes

The functional group is -CHO with a C=O bond drop 'e' of the parent alkane and add 'nal'

HCHO - (1 carbon) Methanal or Formaldehyde

CH3CHO- (2 carbon) Ethanal or Acetaldehyde Slide 57 / 97 Aldehydes, Ketones and Acids The way the carbonyl group is bonded to the main body of the molecule is different in acids, ketones and aldehydes

The C=O is between two other carbon atoms ( alkyl groups) in the molecule

The C=O group is at the end ( terminal carbon) of the molecule and should be connected to a H atom

The C=O bond should be connected to an OH group Slide 58 / 97

28 What is the name of the functional group shown in the following figure? (R = any carbon group) R-C=O

R

A carbonyl B ketone C aldehyde D carboxyl E hydroxyl Slide 59 / 97 Ester

The functional group is -COOR where R could be another alkyl group. 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)

CH3COOH + CH3OH --> CH3COOCH3

CH3COOCH3 methyl acetate

CH3COOC2H5 ethyl acetate

C2H5COOCH3 methyl propanoate Slide 60 / 97

Ether

The functional group is an O atom sandwiched between two carbon groups

CH3-O- CH3 dimethyl ether

They are highly flammable and used as solvents in organic synthesis Slide 61 / 97

Groups with a Carbon–Oxygen Double Bond (Carbonyl Groups) Slide 62 / 97 Amides Amides are formed by the reaction of carboxylic acids with amines.

RCOOH + H2NR' -->

-H O 2

CONH linkage is known as the amide linkage ( peptide) in proteins

This linkage is formed when several amino acids join with their acid and amino groups together. Slide 63 / 97

29 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 Slide 64 / 97

30 What is the name of the functional group shown below.

A carbonyl B ketone C aldehyde D carboxyl E hydroxyl Slide 65 / 97

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

A an alcohol such as ethanol B a monosaccharide such as glucose C a steroid such as testosterone D an amino acid such as glycine E a hydrocarbon such as benzene Slide 66 / 97

32 What type of functional group is shown in the compound below?

A carbonyl B ketone C aldehyde D carboxyl E hydroxyl Slide 67 / 97

33 Which molecule contains an amine functional group?

Slide 68 / 97

34 Which molecule contains an aldehyde functional group?

Slide 69 / 97

35 Which molecule contains an alcohol functional group?

Slide 70 / 97

36 Which one of the following is not an alcohol?

A acetone B glycerol C ethanol D cholesterol E ethylene glycol Slide 71 / 97

Macromolecules

Macromolecules are large molecules composed of smaller molecules.

They 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. Slide 72 / 97

Macromolecules

Three of the classes of life’s organic molecules are polymers:

Proteins Carbohydrates Nucleic acids

There are some macromolecules that are not polymers:

lipids phospholipids steroids Slide 73 / 97

Polymers

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

Polymer Made of these monomers Proteins Amino acids Carbohydrates Simple sugars (monosaccharides) Nucleic acids Nucleotides Slide 74 / 97

Polymers

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

Monomers form larger molecules by condensation short polymer reactions called Monomer dehydration reactions

longer polymer Slide 75 / 97

Amino Acids and Proteins

Proteins are formed when several amino acids combine together

Acid and amine end of the molecules join together to form long peptide chain

Peptide chain with 50 or more amino acids can form an individual protein. Slide 76 / 97

Carbohydrates (sugars) Simple sugars are poly-hydroxy aldehydes or ketones.

Table sugar, (sucrose) is made up of glucose and fructose.

They all have several hydroxyl groups in their structure that makes them soluble in water.

C Glucose and fructose are monosaccharides.

Sucrose is a disaccharide.

glucose fructose (monosaccharide) Slide 77 / 97

Carbohydrates (sugars)

In solution, they form cyclic structures.

These can form chains of sugars that form structural molecules such as starch and cellulose. Slide 78 / 97 Nucleic Acids

Nucleic acids are made up of monomer units called nucleotides

3- Sugar + Base + PO4 = nucleotide Slide 79 / 97 Nucleic Acids

Two of the building blocks of RNA and DNA are sugars (ribose or deoxyribose)

and cyclic bases (adenine, guanine, cytosine, and thymine or uracil) Slide 80 / 97

RNA DNA

Acid Ribonucleic acid Deoxyribonucleic acid

Sugar ribose deoxyribose

Bases A, C, G and U A, C, G and T

Function make proteins carry genetic code Slide 81 / 97 Nucleic Acids

Nucleotides combine to form the familiar double-helix form of the nucleic acids

The blue ribbon is the sugar/ phosphate backbone

The bases are the rungs in the (spiral) ladder

The nucleotides join together via hydrogen bonding through their bases A-T, C-G etc. Slide 82 / 97

37 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 Slide 83 / 97

38 Glucose is a type of ______.

A amino acid B protein C carbohydrate D nucleotide E nucleic acids Slide 84 / 97

39 Nucleic acids are made up of ______.

A amino acids B proteins C carbohydrates D nucleotides E sugars Slide 85 / 97

40 A nucleotide consists of ______.

A glucose + fructose + amino acid B glucose + fructose + phosphate group C amino acid + protein + phosphate group D sugar + base + amino acid E sugar + base + phosphate group Slide 86 / 97

41 Polymers of polysaccharides and proteins are all synthesized from monomers by which process?

connecting monosaccharides together A (condensation reactions) B the addition of water to each monomer (hydrolysis) C the removal of water (dehydration reactions) D ionic bonding of the monomers the formation of disulfide bridges E between monomers Slide 87 / 97

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 Slide 88 / 97

Fats and Fatty Acids 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

CH2OH

CH2OH

CH2OH

a fatty acid glycerol Slide 89 / 97

Dehydration Synthesis

The attachment of a fatty acid to glycerol results in a removal of a water molecule. Slide 90 / 97

The diagram shows three fatty acids added to glycerol producing a fat molecule. Slide 91 / 97

Saturated and Unsaturated Fatty Acids

Saturated fatty acids Have the maximum number of hydrogen atoms possible

Have no double bonds in their carbon chain

Mainly animal origin

Unsaturated fatty acids Have one or more double bonds

When hydrogenated ( add more Hydrogen) they become solid and saturated

Mainly plant origin Slide 92 / 97

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 Slide 93 / 97

Steroids

Are lipids characterized by a carbon skeleton consisting of three or more fused rings

cholesterol Slide 94 / 97

42 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. They provide the least amount of energy in C living organisms D Only A and B are correct. E A, B, and C are correct. Slide 95 / 97

43 Saturated fatty acids

A are the predominant fatty acid in corn oil.

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

have a higher ratio of hydrogen to carbon than do C unsaturated fatty acids. D are usually liquid at room temperature.

E are usually produced by plants. Slide 96 / 97

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

a decrease in the number of carbon-carbon A double bonds in the oil (fat) molecules

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

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

D A and C only

E A, B, and C Slide 97 / 97