Carbon and the Molecular Diversity of Life

Page
2

Slide 10

Fig. 4-4

Hydrogen

(valence = 1)

Oxygen

(valence = 2)

Nitrogen

(valence = 3)

Carbon

(valence = 4)

H

O

N

C

Slide 11

Carbon atoms can partner with atoms other than hydrogen; for example:

Carbon dioxide: CO2

Urea: CO(NH2)2

O = C = O

Slide 12

Fig. 4-UN1

Urea

Slide 13

Molecular Diversity Arising from Carbon Skeleton Variation

Carbon chains form the skeletons of most organic molecules

Carbon chains vary in length and shape

Animation: Carbon Skeletons

Slide 14

Fig. 4-5

Ethane

Propane

1-Butene

2-Butene

(c) Double bonds

(d) Rings

Cyclohexane

Benzene

Butane

2-Methylpropane

(commonly called isobutane)

(b) Branching

(a) Length

Slide 15

Fig. 4-5a

(a) Length

Ethane

Propane

Slide 16

Fig. 4-5b

(b) Branching

Butane

2-Methylpropane

(commonly called isobutane)

Slide 17

Fig. 4-5c

(c) Double bonds

1-Butene

2-Butene

Slide 18

Fig. 4-5d

(d) Rings

Cyclohexane

Benzene

Slide 19

Hydrocarbons

Hydrocarbons are organic molecules consisting of only carbon and hydrogen

Many organic molecules, such as fats, have hydrocarbon components

Hydrocarbons can undergo reactions that release a large amount of energy

Slide 20

Fig. 4-6

(a) Mammalian adipose cells

(b) A fat molecule

Fat droplets (stained red)

100 µm

Slide 21

Isomers

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

Animation: Isomers

Slide 22