AP Biology - Unit 1: Elements of Life

Organic Compounds

Compounds that contain carbon and hydrogen

Carbon

• Has four valence electrons

• Can form single, double, and triple covalent bonds

• Can create long chains or rings

Hydrocarbons

Organic molecules consisting only of hydrogen and carbon that can create the foundation of more complex molecules

Carbon Skeleton

The carbon framework that forms the backbone of organic molecules

• Length

• Branching

• Double Bond Positions

• Rings

Carbon Chain

A connected sequence of carbon atoms that forms the backbone of many organic molecules

Ring

A cyclic arrangement of carbon atoms in a molecule

Branching

Side chains that branch off the main carbon chain, affecting shape and properties

Functional Group

Specific groups of atoms attached to a carbon skeleton that participate in chemical reactions

Hydroxyl Group

The -OH group (found in alcohols)

Carbonyl Group

The C=O group (found in aldehydes and ketones)

Carboxyl Group

The -COOH group (acidic functional group found in acids)

Methyl Group

The -CH3 group (a common alkyl substituent)

Sulfhydryl Group

The -SH group (found in cysteine: can form disulfide bonds)

Amino Group

The -NH2 group (foundational for amino acids and amines)

Phosphate Group

The -OPO3 group (found in glycerol phosphate and nucleic acids: important in energy transfer and backbone chemistry)

Covalent Bonds

Bonds created by sharing electrons between atoms

• Single (sharing one e^- )

• Double (sharing two e^- )

• Triple (sharing three e^- )