Chapter 4: Carbon and the Molecular Diversity of Life

carbon electron configuration

• 2 elects in the first shell and 4 in the second

carbon’s chemical reactivity

• never really loses or gains 4 electrons → completes its valence shell by sharing electrons → 4 covalent bonds

carbon forms what kind of bonds?

single and double covalent

what shape does a molecule with multiple carbon atoms create?

tetrahedral

what shape does a two carbon atom joined by a double bond create?

bonds lie in the same plane

the number of unpaired electrons in the valence shell of an atom is equal to…

the valence and number of covalent bonds

what are the most frequent bonding partners of carbon…

hydrogen, oxygen, and nitrogen

hydrocarbons

organic molecules made up of only carbon and hydrogen

hydrocarbons are a major component of

petroleum

fats

contain long hydrocarbon tails and the tails are attached to a non-hydrocarbon component

petroleum and fats are

hydrophobic (bc their many non polar carbon-hydrogen bonds)

hydrocarbons can undergo reactions and release

a large amount of energy

isomers definition

compounds with the same molecular formula BUT different structures → which leads to different chemical properties

cis-trans isomers (geometric isomers)

same covalent partnerships

cis-trans isomers (geometric isomers)

differ in spatial arrangement and their double bond restricts rotation(lock atoms in specific positions)

Enantiomer definition

isomers that are mirror images of each other

Enantiomers conditions formation

occurs when an asymmetric carbon is present and bonded to 4 diff atoms or groups (four groups can be arranged in two distinct spatial configurations that are non-superimposable mirror images)

bio activity of enantiomer

only 1 enantiomer is active at a time and the other enantiomer is inactive or functionally different

functional significance of enantiomer

small differences between enantiomers can lead to major functional changes → due to emergent properties that arise from the specific 3D arrangement

the unique properties of an organic molecule depend on

arrangement of its carbon skeleton and the chemical groups attached to that skeleton

the chemical groups

contribute to each molecule’s distinct characteristics and can replace hydrogen atoms in hydrocarbons

chemical groups can

• be involved in chemical reactions

• affect the shape and function of the molecule

• give the molecule its unique properties

ex (of chemical groups) : steroid hormones

testosterone and estradiol → same basic carbon skeleton, BUT differ in chemical groups attached, shape, and biological effects

functional groups

• Hydroxyl group

• Carbonyl group

• Carboxyl group

• Amino group

• Sulfhydryl group (HYDROPHOBIC)

• Phosphate group

• Methyl group (NON-REACTIVE)

ATP

important to organic phosphate and is the primary energy transfer molecule in living cells

ATP is made of

organic molecule called adenosine

when ATP reacts with water

One phosphate group is removed → molecule becomes ADP

ATP (storage)

“store“ energy→holds the potential to release energy when reacting with water

ATP (release)

released energy is used to power various cellular processes