- Carbon is essential for all life → leads to diversity, forms cell structure, and is used to build all macromolecules
- Diversity of organisms due to carbon’s ability to build long chains of itself, bond to lots of molecules & form a wide variety of compounds (chemical versatility) bcuz has 4 valence electrons
- Form strong bonds with C, H, O, N
- Organic compound includes carbon; Inorganic compound does not include carbon
- Factors that determine an organic molecules’ properties
- Carbon Backbone – central part of organic molecule, bonding sites of atoms that determines their structure (function/properties),
- Rings, linear, branching, single/double bond: shape determines function
- Carbon atoms bond to other carbon atoms to form very long carbon chains/skeleton
- Functional Groups – branch off carbon backbone & determine chemical properties of an organic compound
- In a reaction the backbone is unchanged & only functional groups react
- Carbon Backbone – central part of organic molecule, bonding sites of atoms that determines their structure (function/properties),
Hydrocarbons
- Long chains of covalently bonded carbon and hydrogen
- Come in many structures which determine properties: single, double, or triple bonds which makes it more rigid
- Make up lipids and contains lots of energy (lots of bonds)
- Nonpolar (Hydrophobic)
- Only polar if has electronegative charge (O2, Su, F, N — electronegative atoms)
Isomers
- “Compounds with same formula but diff arrangement of atoms” = structure determines function
- Structural: placement of carbons is diff which results in diff bonding functional groups and properties
- Geometric: functional groups branching of backbone are diff caused by variations around carbon double bond
- Cis: functional groups on same side
- Trans: functional groups on opp side
- Enantiomers/Stereoisomers: molecules are mirror images of each other bcuz of asymmetric carbon
Functional Groups Continued 
- Affect structure and function
- Ex: determine if amino acid is polar or nonpolar
- All life does NOT require same elements
- TRUE for amino acids which always have amino and carboxyl group
| Functional Group | Examples | Characteristics |
| -OH Hydroxyl | Alcohols (ethanol, glycerol) | Polar, hydrophilic |
| -COOH Carboxyl
– C double bonded to oxygen, single bond to OH |
Amino acids, fatty acids | Polar, hydrophilic, weak acid |
| -C=O Carbonyl | acidic | |
| -NH₂ Amino Group | Amino acids | Polar, hydrophilic, weak base |
| -PO₄ Phosphate | DNA, ATP, phospholipids | Polar, hydrophilic, acid |
| -CH₃ Methyl | Fatty acids, oils, waxes | Nonpolar, hydrophobic |
| -SH Sulfhydryl | -thiols | Stabilize protein 3rd structure |