UN PEQUEÑO APORTE

1. EL CARBONO,
COMPONENTE ESENCIAL
DE LAS CÉLULAS
Mauricio moreno
bogota
2016

2. Importancia del carbono
El Carbono permea todo el mundo viviente
— desde la organización estructural de
las células, pasando por los
requerimientos energéticos, hasta la
conservación de la información genética.
El carbono es un condicionamiento para
la existencia de la biosfera.

3. Compuestos orgánicos
El Hidrógeno y otros elementos se unen
covalentemente al carbono para formar
en los seres vivos:
Carbohidratos
Lipidos
Proteínas
Acidos nucleicos

4. El átomo de carbono
En su último nivel
posee cuatro
electrones;
pudiendo tener 8.
Cada átomo de
carbono puede
unirse máximo con
cuatro elementos
compartiendo un par
de electrones.

5. Los átomos de carbono se
pueden unir formando
cadenas lineales, ramificadas
o anillos.
La principal característica es
su capacidad de unirse
con otros átomos de
carbono y de otros
elementos y formar
millones de compuestos.
Glucosa

6. DIFERENTES MODELOS DE
LAMOLECULA DE HEMOGLONINA
Ball-and-stick model Space-filling model
Ribbon model

7. •Configuración electrónica del carbono
7

8. ORBITALES “S”

9. ORBITALES “P”

10. •Clasificación de orbitales híbridos:
•Orbitales hibridos sp
•Orbitales hibridos sp2
•Orbitales híbridos sp3

11. ORBITAL HÍBRIDO sp3
•Cuando se mezcla un orbital “s” con tres
orbitales “p”, de la misma subcapa se
forman 4 orbitales híbridos “sp3
“ (ese pe
tres(.

12. ORBITALES HIBRIDOS

13. 13

14. El átomo de carbono

15. METANO: LA SUSTANCIA
ORGÁNICA MÁS SIMPLE.
Structural formula
Ball-and-stick
model
Space-filling
model
HH
H
H
C

16. ORBITAL HÍBRIDO sp2
Siempre que se mezcla cierto número de
orbitales atómicos se obtiene el mismo
número de orbitales híbridos. Cada uno de
éstos es equivalente a los demás pero
apuntan en dirección distinta. Cuando se
mezclan un orbital “s” con dos orbitales “p,
se forman 3 orbitales híbridos “sp2
“.

17. ORBITALES HIBRIDOS

19. 19

21. Orbital Híbrido “ sp“
•Esta hibridación ocurre cuando se
mezcla el orbital “s” y uno de los
orbitales “p”, para generar dos nuevos
orbitales: Ejemplo BeF2

22. ORBITALES HIBRIDOS

23. 23

24. GRUPOS FUNCIONALES
Son átomos o grupos de átomos que se unen
covalentemente a una cadena carbonada dandole
diferentes propiedades.
-CH3 Grupo metilo
Grupo Hidroxilo- OH
Grupo Amino- NH3
+
Grupo Carboxilo- COOH
Grupo Fosfato- PO3
-
Grupo Sulfhidrilo- SH

25. 25

26. 26

27. HIDROCARBUROS

28. HIDROCARBUROS
ALIFATICOS

29. ALCANOS

32. ETENO

33. ACETILENO

34. AROMATICOS

35. AROMATICOS

37. ALCOHOLES

38. ALCOHOLES

41. ALDEHIDOS Y CETONAS

42. ACIDOS CARBOXILICOS

43. ACIDOS CARBOXILICOS

44. ACILOS

46. ESTERES

48. ETERES

49. AMINAS

52. AMIDAS

53. FENOLES

54. NITRILOS

57. POLIFUNCIONALES

58. CARBOHIDRATOS

59. LIPIDOS

60. NUCLEOTIDOS

74. 74
Hidrocarburos
• Compuestos de carbono e hidrogeno.
• Saturados (alcanos) los elementos
unidos al carbono lo hacen a través de
un enlace simple.
• Formula general
[CnH2n+2]
H C
H
H
C
H
H
H

75. 75
• Insaturados: Contienen enlaces
carbono-carbono de tipo multiple
(doble o triple)
H C
H
H
C
H
C
H
H

76. 76
Alcanos: hidrocarburos saturados
• Hidrocarburos saturados, CnH2n+2
– “Saturados” porque ellos no pueden unir
más átomos de hidrogeno.

77. 77
Alcanos: hidrocarburos saturados
• Hidrocarburos son moleculas compuestas de carbono
e hidrogeno.
– Cada carbono forma cuatro enlaces químicos.
– Un hidrocarburo saturado solo contiene enlaces sencillos
C – C y sus moléculas contienen el máximo número de átomos
de H.
– Los hidrocarburos saturados son llamados ALCANOS

78. 78
Metano es una molécula tetraedrica

79. 79
Estructura de Lewis para el etano.

80. 80

81. 81
Propano

82. 82
Butano

83. 83
Los 10 “Normales” Alcanos
NameName FormulaFormula M.P.M.P. B.P.B.P. # Structural Isomers# Structural Isomers
• Methane CH4 -183 -162 1
• Ethane C2H6 -172 -89 1
• Propane C3H8 -187 -42 1
• Butane C4H10 -138 0 2
• Pentane C5H12 -130 36 3
• Hexane C6H14 -95 68 5
• Heptane C7H16 -91 98 9
• Octane C8H18 -57 126 18
• Nonane C9H20 -54 151 35
• Decane C10H22 -30 174 75
C1 - C4 are GasesC1 - C4 are Gases
at Room Temperatureat Room Temperature
C5 - C16 are LiquidsC5 - C16 are Liquids
at Room Temperatureat Room Temperature

84. 84
Reglas de la IUPAC para nombrar alcanos
• Nombrar la cadena principalNombrar la cadena principal
• Numerar los átomos de carbono de la cadenaNumerar los átomos de carbono de la cadena
principal empezando por el más cercano a lasprincipal empezando por el más cercano a las
ramificacionesramificaciones
• Nombrar las ramificaciones con la teminación ilo,Nombrar las ramificaciones con la teminación ilo,
ejemplo metilo, etilo, propilo etc.ejemplo metilo, etilo, propilo etc.
• Cuando hay más de una ramificación nombrarlas en
orden alfabetico
• Finalmente usar prefijosprefijos para indicar multiples
ramificaciones.

85. 85
Reglas de la IUPAC para nombrar
alcanos
1. Para alcanos después del butano,
agregar-ano a la raíz griega del
número de átomos de carbonos de la
cadena más larga .
C-C-C-C-C-C : hexano
2. Sustituyentes alquilo: cambiar-ano
por -ilo.
-C2H5 es el etilo.

86. 86

87. 87
Reglas de la IUPAC para nombrar alcanos
3.La posición de los sutituyentes se
especifica con la numeración.
C
|
C-C-C-C-C-C
3-metil-hexano
Empezar desde el extremo más cercano
a la numeración.
4. Nombrar los sutituyentes en orden
alfabetico y usando los prefijos di-, tri-
etc.

88. 88

89. 89
Isomeros estructurales
• Isomeros: moléculas que
tienen la misma formula
molecular, pero diferente
formula estructural CH3
CH2
CH2
CH2
CH3
CH3
CH2
CH
CH3
CH3
n-pentano, C5H12
2-metilbutano, C5H12

90. 90
Ejemplo : 2,2-dimetilpentano2,2-dimetilpentano
heptanoheptano
CH3
1
C
CH23
CH2
4
CH35
CH3
CH3

91. 91
Ejemplo:
3-etil-2,4-dimetilheptano3-etil-2,4-dimetilheptano
3-etil-5-metiloctano
CH3
CH
CH
CH
CH2
CH2
CH3
CH2
CH3
CH3
CH3

92. 92
Reacciones de los alcanos
• Reacciones de combustion
2C4H10 + 13 O2 8CO2 + 10 H2O
Reacciones de sustituciónReacciones de sustitución
CHCl Cl CCl HCl
h
3 2 4+ +
ν
CH4 + Cl2 CH3Cl + HCl
CH3Cl + Cl2 CH2Cl2 + HCl
CH2Cl2 + Cl2 CH Cl3 + HCl

93. 93
Reacciones de deshidrogenaciónReacciones de deshidrogenación
CH3CH3 CH2 CH2 + H2
Etileno

94. 94
Ciclo alcanosCiclo alcanos
• Formación de anillos, CnH2n
CH3
CH2
CH3 CH2
C
H2
CH2
n-propane
C3H8
cyclopropane
C3H6
60° bond angle
unstable!!
109.5° bond angle

95. 95
Ciclohexano –conformaciones de silla y
bote
• El Ciclohexano no es una molécula plana.
• El bote y la silla (99%) son dos conformaciones

96. 96
Alquenos y alquinos
Alquenos: hidrocarburos que contienen
dobles enlaces carbono-carbono. [CnH2n]
C=C Eteno
C−C=C propeno
Alquinos: hidrocarburos que contienen u
triple enlace carbono-carbono. [CnH2n-2]
C ≡C Etino
C−C−C≡C−C 2-pentino

97. 97
Nomenclatura para los Alquenos
1.La cadena principal debe contener el
doble enlace, al nombarla debe
terminar en -eno
C2H4; CH2=CH2 eteno
2. Cuando hay más de tres carbonos, el
doble enlace se indica con el númerocon el número
más bajo del carbono del enlacemás bajo del carbono del enlace
C=C−C−C 1-buteno

98. 98
Isomeros de los Alquenos:
Cis y Trans
El doble enlace no permite los giros
alrededor del mismo.
CH3 CH3 CH3
CH = CH CH = CH
cis trans CH3

99. 99
Reacciones de adición

100. 100
Hidrogenación
H H H H
Ni
H–C=C–H + H2 H–C–C–H
H H
eteno etano
CHCH33-CH-CH33

101. 101
Halogenacion
H H H H
Ni
H–C=C–H + Cl2 H–C–C–H
Cl Cl
eteno dicloroetano

102. 102
Reacciones de Halogenación
CH2 CHCH2CH2CH2 + Br2
CH2Br CHBrCH2CH2CH2
1,2-dibromopentano
1-penteno

103. 103
Alquinos, CnH2n–2
Triple enlace Carbono-carbono
Nombres terminados en -ino
HC≡CH etino(acetileno)
HC≡C-CH3 propino

104. 104

105. 105
1 2 3 4
CH2=CHCH2CH3 1-buteno
CH3CH=CHCH3 2-buteno
CH3CH≡CHCH3 2-butino

106. 106
Preguntas
Cuál es el nombre de los siguientes compuestos:
A. CH3CH2C≡CCH3
CH3
B. CH3C=CHCH3
2-pentino
2-metil-2-buteno

107. 107
Preguntas
c.
CH3CH2C CCHCH2CH3
CH2
CH3
1 2 3 4 5 6 7
5-etil-3-heptino

108. 108
Hidrocarburos aromaticos
• Ciclos que contienen enlaces
sencillos y dobles alternados.
– Se llaman “aromaticos” (por el aroma
que generan).
– La presencia de la alternacia de
enlaces sencilos y dobles le confiere
propiedades particulares como
participar en reacciones de sustitución
y no de adición.

109. 109
Estructuras de Lewis para el benceno

110. 110
Benzene C6H6
sp2
sp2sp2

111. 111
Shorthand notation for benzene rings

112. 112
The bonding in the benzene ring is a
combination of different Lewis structures.

113. 113

114. REACCIONES DE
SUSTITUCION DEL BENCENO
114

115. 115

116. 116
Nomenclatura de los derivados del benceno

117. 117
Sistemas Aromaticos más complejos

118. 118
Halogenuros de alquilo
Son alcanos en los cuales un hidrogeno ha
sido reemplazado por un halogeno(F, Cl, Br,
or I)
CH3Br bromometano
Br
CH3CH2CHCH3 2-bromobutano
Cl
clorociclobutano

119. 119
Nomenclatura
bromociclopentano
1,3-diclorociclohexano
Br
Cl
Cl
1 2
3

120. 120
Nomenclatura
El nombre del siguiente compuesto es:
Cl CH3
CH3CH2CHCH2CHCH3
1) 2,4-dimetilhexano
2) 4-cloro-5-metilhexano
3) 4-cloro-2-metilhexano

121. 121
Alcoholes: R–OH
• El grupo hidroxilo –OH hace al alcohol polar
y puede formar puentes de hidrogenopuentes de hidrogeno. LoLo
hace soluble en aguahace soluble en agua
• El Etanol es producto de la fermentacion
yeastC6H12O6
Glucosa
2CH3CH2OH
Etanol + 2 CO2
CO + 2H2O CH3OH
Metanol
• El metanol es producto de la hidrogenacion
industrial del monoxido de carbono

122. 122
Usos de los alcoholes
• Metanol es usado para la síntesis de
adhesivos, fibras, plasticos y combustble
para motor.
• El metanol es toxico para los humanos y
puede causar ceguera y muerte.
• El Etanol se le adiciona a la gasolina para
formar gasohol. Es usado como solvente.
• Producción comercial del etanol:
CH2=CH2 + H2O CH3CH2OH

123. 123
Clases de alcoholes
R CH2OH Primary alchol
CHOH
R'
R
Secondary alcohol
CR'
R
R"
OH
Tertiary alcohol
Los alcoholes se pueden clasificar de acuerdo al
numero de carbonos unidos al carbono dondenumero de carbonos unidos al carbono donde esta
el grupo –OH.

124. 124
Nombrando los Alcoholes
En la IUPAC la terminación ano del alcano
es reemplazada por -ol.
CH4 metano
CH3OH metanol (alcohol metilico)
CH3CH3 etano
CH3CH2OH etanol (alcohol etilico)

125. 125
OH
Phenol
(Aromatic alcohol)

126. 126
CH3CH2CH2OH 1-propanol
OH
CH3CHCH3 2-propanol
CH3 OH
CH3CHCH2CH2CHCH3 5-metil-2-hexanol5 2

127. 127
OH
CH3CHCH3
2-propanol (alcohol isopropilico)
HO-CH2-CH2-OH
1,2-etanodiol1,2-etanodiol (etilenglicol)
OH
glicerol HO-CH2-CH-CH2OH

128. 128
A. OH
CH3CHCHCH2CH3
CH3
OH
B.
3-metil-2-pentanol
Ciclobutanol

129. 129
Reacciones de los alcoholes
Combustion
CH3OH + 2O2 CO2 + 2H2O + Energía
Deshidratacion
H OH
calor
H-C-C-H H-C=C-H + H2O
H H H H
alcohol alqueno

130. 130
Ethers
• Contain an -O--O- between two carbon groups
• Simple ethers named from -yl names-yl names of the
attached groups and addingadding etherether.
CH3-O-CH3 dimethyl ether
CH3-O-CH2CH3 ethyl methyl ether

131. 131
Aldehydes and Ketones
In an aldehyde, an H atomH atom is attached to a
carbonyl group
O carbonyl group

CH3-C-H
In a ketone, two carbon groupstwo carbon groups are attached to
a carbonyl group
O carbonyl group

CH3-C-CH3

132. 132
Naming Aldehydes
IUPAC Replace the -e in the alkane name -al
Common Add aldehyde to the prefixes form
(1C), acet (2C), propion(3), and butry(4C)
O O O
  
H-C-H CH3-C-H CH3CH2C-H
methanal ethanal propanal
(formaldehyde) (acetaldehyde) (propionaldehyde)
methane
ethane propane

133. 133
Aldehydes as Flavorings
CH
O
CH
O
HO
OCH3
CH=CH CH
O
Benzaldehyde Vanillin Cinnamaldehyde
(almonds) (vanilla beans) (cinnamon)

134. 134
Naming Ketones
In the IUPAC name, the -e in the alkane name is
replaced with -one
In the common name, add the word ketone
after naming the alkyl groups attached to the
carbonyl group
O O
 
CH3 -C-CH3 CH3-C-CH2-CH3
Propanone 2-Butanone
(Dimethyl ketone) (Ethyl methyl ketone)
O
Cyclohexanone
Acetone
propane butane
cyclohexane

135. 135
Preparation of aldehydes and Ketones
They are produced by oxidation of alcohols:
CH3CH2OH
Oxidation
CH3CHCH3
OH
Oxidation
CH3CCH3
O
CH3C
O
H
acetaldehyde
acetone
Primary alcohol
Secondary alcohol
ethanal
propanone

136. 136
Question
Classify each as an aldehyde (1), ketone (2)
or neither(3).
O

A. CH3CH2CCH3 B. CH3-O-CH3
CH3 O

C. CH3-C-CH2CH D.
CH3
O

137. 137
Solution
Classify each as an aldehyde (1), ketone (2)
or neither(3).
O

A. CH3CH2CCH3 2 B. CH3-O-CH3 3
CH3 O

C. CH3-C-CH2CH 1 D. 2
CH3
O

138. 138
Question
Name the following
O

A. CH3CH2CCH3 B.
CH3 O

C. CH3-C-CH2CH
CH3
O

139. 139
Solution
O

A. CH3CH2CCH3 B.
2-butanone (ethyl methyl ketone)
CH3 O

C. CH3-C-CH2CH
cyclohexanone
CH3
2,2-dimethylbutanal
O

140. 140
Question
Draw the structural formulas for each:
A. 3-Methylpentanal
B. 2,3-Dichloropropanal
C. 3-Methyl-2-butanone

141. 141
Solution
Draw the structural formulas for each:
CH3 O

A. 3-Methylpentanal CH3CH2CHCH2CH
Br O

B. 2,3-Dibromopropanal Br-CH2CHCH
O

C. 3-Methyl-2-butanone CH3CHCCH3

142. 142
Carboxylic Acids and Esters
Carboxyl Group
Carboxylic acids contain the carboxyl group
as carbon 1.
O
R ||
CH3 —C—OH : CH3—COOH
carboxyl group

143. 143
Naming Carboxylic Acids
Formula IUPAC Common
alkan -oic acid prefix – ic acid
HCOOH methanoic acid formic acid
CH3COOH ethanoic acid acetic acid
CH3CH2COOH propanoic acid propionic acid
CH3CH2CH2COOH butanoic acid butyric acid

144. 144
Naming Rule for Carboxylic acids
• Identify longest chain
• (IUPAC) Number carboxyl carbon as 1carboxyl carbon as 1
CH3
|
CH3 —CH—CH2 —COOH
IUPAC 3-methylbutanoic acid
1234

145. 145
Question
Give IUPAC name:
A. CH3COOH
CH3
|
B. CH3CHCOOH
2

146. 146
Solution
A. CH3COOH
ethanoic acid; acetic acid
CH3
|
B. CH3CHCOOH
2-methylpropanoic acid;

147. 147
Preparation of carboxylic acids
• Oxidation of primary alcohols
CH3CH2OH CH3COOH
KMnO4

148. 148
Reaction of carboxylic acid with alcohol
CH3C
O
OH + H OCH2CH3
CH3C
O
OCH2CH3
+
H2O
Ester
Carboxylic acid Alcohol
Esterification

149. 149
Esters
In a ester, the H in the carboxyl group is
replaced with an alkyl group
O
||
CH3 —C—O —CH3 : CH3—COO —CH3
ester group
•Esters give fruity odors

150. 150
Naming Esters
• The parent alcohol is named first with a –yl
ending
• Change the –oic ending of the parent acid to
–ate
acid alcohol
O
|| methyl
CH3 —C—O —CH3
Ethanoate methyl ethanoate (IUPAC)
(acetate) methyl acetate (common)

151. 151
Some esters and their names
Flavor/Odor
Raspberries
HCOOCH2CH3 ethylmethanoate (IUPAC)
ethylformate (common)
Pineapples
CH3CH2CH2 COOCH2CH3
ethylbutanoate (IUPAC)
ethylbutyrate (common)

152. 152
Question
Give the IUPAC and common names of
the following compound, which is
responsible for the flavor and odor of
pears.
O
||
CH3 —C— O —CH2CH2CH3

153. 153
Solution
O
|| propyl
CH3 —C—O —CH2CH2CH3
propylethanoate (IUPAC)
propyl acetate (common)

154. 154
Question
Draw the structure of the following compounds:
A. 3-bromobutanoic acid
B. Ethyl propionoate

155. 155
Solution
A. 3-bromobutanoic acid
Br
|
CH3CHCH2COOH
B. Ethyl propionoate
O
||
CH3 CH2 COCH2CH3 CH3CH2COOCH2CH3

156. 156
Hydrolysis of esters
• Esters react with water and acid catalyst
• Split into carboxylic acid and alcohol
O
|| H+
H—C—O—CH2CH3 + H2O
O
||
H—C—OH + HO—CH2CH3
-OHH

157. 157
Amines
• Organic compounds of nitrogen N;
derivatives of ammonia
• Classified as primary, secondary, tertiary
CH3 CH3
 
CH3—NH2 CH3—NH CH3—N — CH3
Primary Secondary Tertiary
one N-C two N-C three N-C
bond bonds bonds

158. 158
Naming Amines
IUPAC aminoalkane Common alkylamine
CH3CH2NH2 CH3—NH —CH3
aminoethane N-methylaminomethane
(ethylamine) (dimethylamine)
NH2
|
CH3CHCH3
2-aminopropane Aniline N-methylaniline
(isopropylamine)
NH2 NH CH3

159. 159
Question
Give the common name and classify:
A. CH3NHCH2CH3
CH3
|
B. CH3CH2NCH3

160. 160
Solution
A. CH3NHCH2CH3
ethylmethylamine, (Secondary)
CH3
|
B. CH3CH2NCH3
ethyldimethylamine, (Tertiary)

161. 161
Question
Write a structural formula for
A. 2-aminopentane
B. 1,3-diaminocyclohexane

162. 162
Solution
A. 1-aminopentane
CH3CH2CH2CH2CH2-NH2
B. 1,3-diaminocyclohexane
NH2
NH2

163. 163
Polymers
Poly= many; mers=parts
• Polymers are large, usually chainlike
molecules that are built from small
molecules called monomers joined by
covalent bonds
Monomer Polymer
Ethylene Polyethylene
Vinyl chloride Polyvinyl
chloride
Tetrafluoroethylene Teflon

164. 164
Some common synthetic polymers, their
monomers and applications

165. 165
Types of Polymerization
Addition Polymerization:Addition Polymerization: monomers
“add together” to form the polymer,
with no other products. (Teflon)
Condensation Polymerization:Condensation Polymerization: A
small molecule, such as water, is
formed for each extension of the
polymer chain. (Nylon)

166. 166
Addition Polymerization
OH
C C
H
H
H
H
C
OH
H C
H
H
H
C C
H
H
H
H
C
OH
H C
H
H
H
C
OH
H C
H
H
H
C C
H H
H H
The polymerization process
Is initiated by a free radical
A species with
an unpaired
electron such as
hydroxyl free radical
Free radical attacks and break
The π bond of ethylene molecule
To form a new free radical
• Repetition of the process thousands of times creates a long chain
polymer
• The process is terminated when two radicals react to form a bond;
thus there will be no free radical is available for further repetitions.

167. 167
Condensation Polymerization
Formation of Nylon
N
H
H
(CH2)6 N
H
H C
O
O
(CH2)4H
C
O
O H
Hexamethylendiamine Adipic acid
N
H
H
(CH2)6 N
H
C (CH2)4 C
O
O H
O
+ H2O
• Small molecule such as H2O is formed
from each extension of the polymer chain
• both ends are free to react
Dimer
Diamine Dicarboxylic acid

168. 168
N
H
(CH2)6 N
H
( C (CH2)4 C
OO
)n
Nylon

169. 169
Proteins
• Natural polymers made up of α-amino
acids (molecular weight from ≈ 6000 to
>1,000,000 g/mol).
1. Fibrous Proteins: provide structural
integrity and strength to muscle, hair
and cartilage.

170. 170
Proteins
2. Globular Proteins:
 Roughly spherical shape
 Transport and store oxygen and
nutrients
 Act as catalysts
 Fight invasion by foreign objects
 Participate in the body’s regulatory
system
 Transport electrons in metabolism

171. 171
α-Amino Acids
∀−NH2 always attached to the α-carbon (the
carbon attached to −COOH)
•C = α-carbon
H2N C
H
COOH
R

172. 172
Bonding in α-Amino Acids
• + H2O
∀ ↑
•
A peptide linkage (amide group)
•There are 20 amino acids commonly found in proteins.
• Additional condensation reaction produces
polypeptide eventually yielding a protein
CN
H
H
H
R
C
O
N
H
C
H
R'
C
O
OH
Dipeptide
• The protein polymer is built by condensation reaction
between amino acids

173. 173
The 20
Alpha-amino
Acids found
in most
proteins

174. 174
Levels of Structure
•Primary: Sequence of amino acids
in the protein chain. (lycine-alanine-
leucne: (lys-ala-leu).
– So many arrangements can be
predicted.
Tripeptide containing
Glycine, Cysteine, and
Alanine

175. 175
Levels of Structure
•Secondary: The arrangement of the protein chain
in the long molecule (hydrogen bonding determines
this).
• Hydrogen bonding between lone pairs on an
oxygen atom in the carbonyl group of an amino acid
and a hydrogen atom attached to a nitrogen of
another amino acid
C O NH
This type of interaction can occur with the chain
coils to form a spiral structure called αα- helix- helix

176. 176
Hydrogen bonding within a protein chain causes it to form a stable
helical structure called the alpha-Helix
This is found in
fibrous protein like
wool and hair giving
it the elasticity

177. 177
•Tertiary: The overall shape of the protein
(determined by hydrogen-bonding, dipole-
dipole interactions, ionic bonds, covalent
bonds and London forces).
Summary of the Various Types of Interactions that Stabilize the Tertiary
Structure of a Protein: (a) Ionic, (b) Hydrogen Bonding, (c) Covalent, (d)
London Dispersion, and (e) Dipole-Dipole

178. 178
Summary of the Various Types of Interactions that
Stabilize the Tertiary Structure of a Protein:
(a) Ionic,
(b) Hydrogen Bonding,
(c) Covalent,
(d) London Dispersion, and
(e) Dipole-Dipole

179. 179
CarbohydratesCarbohydrates
Food source for most organisms and
structural material for plants.
Empirical formula = (CH2O)n
 Most carbohydrates such as starch and
cellulose are polymers of monosacharides orpolymers of monosacharides or
simple sugar monomerssimple sugar monomers
Monosaccharides (simple sugars) are
polyhydroxy ketones and aldehydes
Pentoses (5-carbon atoms) - ribose, arabinose
Hexoses (6-carbon atoms) - fructose, glucose

180. 180
Some Important Monosaccharides

181. 181
Chiral carbon atoms in fructose
• Molecules with nonsuperimposable
mirror images exhibit optical isomerism
• A carbon atom with different groups
bonded to it in a tetrahedral arrangement
always has a nonsuperimposable mirror
images which gives rise to a pair of
optical isomers

182. 182
Tetrahedral Carbon
atom with four
different substituents
cannot have its
mirror image
superimposed

183. 183
The Mirror Image Optical Isomers of
Glyceraldehyde
*
Chiral carbon
atom

184. 184
Fructose
D-Fructose
H2OHC
C
CHO H
C
O
H OH
C
CH2OH
OHH
*
*
*
There are 3 chiral
Carbon atoms
There are 23
isomers
That differ in the ability
To rotate light

185. 185
Complex carbohydrates
Disaccharides (formed from 2
monosaccharides joined by a glycoside
linkage)
sucrose (glucose + fructose)
Polysaccharides (many monosaccharide
units)
starch, cellulose

186. 186
Sucrose is a disaccharideformed from alpha-D-
glucose and fructose

187. 187
(a) The Polymer Amylose is a Major Component of Starch
and is Made Up of Alpha-D-Glucose Monomers
(b) The Polymer Cellulose, which Consists of Beta-D-
Glucose Monomers

188. 188
Nucleic Acids
• Life is possible because each cell when it
divides can transmit the vital information
about how it works to the next generation
• The substance that stores and transmits
information is a polymer called
deoxyribonucleic acid (DNA)
• DNA together with other similar nucleic acids
called ribonucleic acids is responsible for
the synthesis of various proteins needed by
the cell to carry out its life functions

189. 189
Nucleic Acids
• DNA (deoxyribonucleic acids):
stores and transmits genetic
information, responsible (with RNA)
for protein synthesis. (Molar mass =
several billion)
•RNA (ribonucleic acid): helps in
protein synthesis. (Molecular
weight = 20,000 to 40,000)

190. 190
Monomers of nucleic acid
Nucleotides
1. Five-carbon sugar, deoxyribose in DNA and
ribose in RNA.
2. Nitrogen containing organic base
3. Phosphoric acid molecule, H3PO4
• The base and the sugar combine to form a unit
that in turn reacts with phosphoric acid to
create a nucleotide
• The nucleotides become connected through
condensation reaction that eliminate water to
give a polymer that contain a billion units.

191. 191
The Organic Bases Found in DNA and RNA

192. 192
The base and sugar combine to form a unit that
in turn reacts with phosphoric acid to create the
nucleotide, which is an ester

193. 193
A Portion of a
typical nucleic
acid chain

194. 194
Double helix formation
• According to Watson and Crick (Nobel prize
winners), CAN is composed of two strands (threads)
running in opposite directions that are bridged by
hydrogen bonds between specific pyrimidine groups
on one strand and purine group on the other
• The two strands are twisted into a double α-helix
structure
• The strongest hydrogen bonds form between
adonine and thymine and between guanine and
cystosine. Thus; A-T or G-C bonding interactions
will take place
• The sequence of nucleotides on one strand of the
double helix determines the sequence of the other
• The sequence of the bases determines what
information is stored.

195. 195
(a) The DNA double helix contains two sugar-phosphate
backbones, with the bases from the two strands hydrogen bonded
to each other; the complementarity of the (b) thymine-adenine and
(c) cytosine-guanine pairs

196. 196
Gracias