BIO Final Terms - Chemistry basics and Plasma Membrane

Hydrophobic

nonpolar molecules; repel water

Hydrophilic

polar or charged molecules; attract water

Polar

unequal sharing of electrons; has partial charges; often has O, N, or F

Nonpolar

equal sharing of electrons; usually C–H bonds

Amphoteric Molecules

Can act as acids or bases (ex: water, amino acids)

Ionic bond

electrons are transferred

Covalent bond

electrons are shared

Peptide bond

connects amino acids in proteins

Amino Acids

Building blocks of proteins; contain amine group (NH₂), carboxyl group (COOH), and R group

ATP

Energy released when one phosphate is removed → ADP

Plasma membrane structure

Phospholipid bilayer (regulates entry/exit)

What passes easily in the plasma membrane?

Small nonpolar molecules (O₂, CO₂)

Outer & inner heads

hydrophilic

Middle fatty acid tails

hydrophobic