CARBON AS A BASIS FOR LIFEChapter 4

THE IMPORTANCE OF CARBON

All living organisms based significantly on carbon

Creates a large diversity of biological molecules Includes: proteins, DNA, carbohydrates, lipids, and

others Distinguishes living form nonliving matter

All these molecules are examples of emergent properties

DEFINING ORGANIC CHEMISTRY

Organic compounds are anything containing carbon Hydrocarbon molecules contain only hydrogen

and carbon Simple (CH4) to large and diverse (proteins)

Organic molecule variation exists both w/i individual species and b/w different species

The four main elements of living organisms are? (hint: 96% of the human body) Valence is the number of covalent bonds an

atom can make Valence electrons are ALL electrons in

outermost shell

CARBON’S ABILITY TO BOND 6 electrons, ? in first shell and ? in outer

shell Can donate or accept electrons equally (form an

ion) Usually shares (covalent bonds)

Single, double, or triple

Makes large, complex molecules possible Each line between 2 atoms represents 2

shared electrons

CARBON CARBON BONDING

Skeletons of most organic compounds are carbon chains Straight, branched, or ringed Number and bond type vary

Examples of hydrocarbons

HYDROCARBONS

What constitutes a hydrocarbon? Main components of fossil fuels b/c come

from decomposed living organisms Not major component of living organisms,

but are regions in other molecules Reactions cause large amounts of energy release

Fats – long, nonpolar, hydrophobic tail Serve as stored fuel in animals

Used in gasoline

ISOMERS 2 molecules with the same # of the same atoms,

but different structure = different properties 3 types

Structural Covalently bonded and arranged in different orders Number of configurations increase with increase in number of

carbons Geometric

Covalently the same partners, but different spatial arrangement Double bonds prohibit rotation

Enantiomer Mirror images (R- and L-)

Usually one is inactive Important in pharmaceuticals because both can have different

effects

ISOMER EXAMPLES

Geometric Isomer

Enantiomer

Structural Isomer

4C’s and 8H’s

1 of each

2C’s, 2H’s, and 2 Cl’s

Cl ClCl

Cl

BIOMOLECULAR FUNCTIONING Hydrogens can be replaced by other atom

groupings Arrangement determines properties

May participate directly in reactions or indirectly because of shape

Sex hormones as an example Testosterone vs estradiol

Different actions Minimal differences in structure

FUNCTIONAL GROUPS

AD

EN

OS

INE T

RIP

HO

SP

HATE

(ATP

)

Addition of water removes 1 phosphate to create ADP

HOPO32-

abbreviated as Pi

ATP ‘stores potential to react with water’

ATP + water releases Energy for cell useAddition of water