Carbon and the Molecular Diversity of Life: Campbell Chapters 4 and 5 Study Notes

Organic Chemistry

The branch of chemistry defined specifically as the study of carbon compounds.

Hydrocarbons

Organic molecules consisting exclusively of combinations of carbon ($C$) and hydrogen ($H$) atoms, which are non-polar, hydrophobic, and chemically stable.

Structural Isomers

Molecules that share the exact same molecular formula but possess different structural shapes and arrangements, leading to different chemical properties and biological functions.

Stereoisomers

Isomers that share the same bond structure but differ in the spatial arrangement of atoms around an asymmetric carbon atom due to chirality.

Hydroxyl Group

A functional group consisting of an oxygen atom single-bonded to a hydrogen atom ($-\text{OH}$) that conveys polarity and renders organic compounds (alcohols) hydrophilic.

Carbonyl Group

A functional group featuring an oxygen atom double-bonded to a carbon atom ($=O$); found in aldehydes at the terminal end of a chain and ketones in the middle of a chain.

Carboxyl Group

A functional group ($-\text{COOH}$) that acts as an acid by donating an $H^+$ ion to solution, commonly found in amino acids and fatty acids.

Amino Group

A functional group ($-\text{NH}_2$) that acts as a base by picking up an $H^+$ ion from surrounding solution, present in all amino acids.

Sulfhydryl Group

A functional group ($-\text{SH}$) present in thiols that can form covalent cross-links (disulfide bridges) to stabilize protein structures.

Phosphate Group

A highly reactive functional group ($-\text{PO}_4$ or $-\text{OPO}_3^{2-}$) with a net negative charge, essential for energy transfer between organic molecules such as ATP.

Methyl Group

A non-polar, hydrophobic functional group ($-\text{CH}_3$) that directly affects gene expression regulation and the activity of sex hormones.

Dehydration Synthesis

A chemical reaction that links monomers together into polymers by removing a water molecule ($H_2O$), requiring cellular energy and enzymes.

Hydrolysis

A chemical process that breaks down polymers into individual monomers by adding a water molecule ($H_2O$), catalyzed by specific digestive enzymes.