AP Biology Unit 1 – Chemistry of Life: Ultimate Study Notes

What are the three subatomic particles of an atom and their charges?

Protons (+), Neutrons (0), Electrons (−)

How do you calculate atomic number and mass number?

Atomic number = number of protons; Mass number = protons + neutrons

What is an isotope? Give an example.

Same element, different number of neutrons. Example: Carbon-12 vs Carbon-14

Name the four main types of chemical bonds.

Covalent, Ionic, Hydrogen, Van der Waals

Difference between polar and nonpolar covalent bonds?

Polar = unequal sharing of electrons (e.g., H₂O); Nonpolar = equal sharing (e.g., O₂, CH₄)

What are hydrogen bonds and why are they important?

Weak attraction between H and electronegative atoms; important in water, DNA, proteins

What makes water a unique molecule? List key properties.

Polar, cohesion, adhesion, high specific heat, high heat of vaporization, ice less dense than water

What does CHAIS stand for in water properties?

Cohesion, High Specific Heat, Adhesion, Ice floats, Solvent

What are the monomers and polymers of carbohydrates?

Monomer = monosaccharides; Polymer = polysaccharides (starch, glycogen, cellulose, chitin)

Function of carbohydrates?

Energy and structural support

Function of lipids and types?

Energy storage, membranes, signaling; Types = triglycerides, phospholipids, steroids

Describe a phospholipid’s structure in a membrane.

Hydrophilic head faces outward, hydrophobic tails face inward

Functions of proteins?

Enzymes, structure, transport, defense

What is the monomer of proteins?

Amino acids (20 types

Levels of protein structure?

Primary (sequence), Secondary (α-helix/β-sheet), Tertiary (3D folding), Quaternary (multiple polypeptides)

Examples of proteins and their functions?

Hemoglobin = O₂ transport; Lactase = enzyme that breaks down lactose

Monomers and polymers of nucleic acids?

Monomer = nucleotide; Polymer = DNA & RNA

DNA vs RNA key differences?

DNA = double helix, A-T, G-C; RNA = single strand, U instead of T

Function of nucleic acids?

Store and transfer genetic information; template for proteins

Name common functional groups in biomolecules.

Hydroxyl (-OH), Carbonyl (C=O), Carboxyl (-COOH), Amino (-NH₂), Sulfhydryl (-SH), Phosphate (-PO₄), Methyl (-CH₃)

Dehydration synthesis vs hydrolysis?

Dehydration synthesis = build polymers, remove water; Hydrolysis = break polymers, add water

What is an enzyme and how does it work?

Biological catalyst that reduces activation energy; can be denatured by extreme pH, temperature, inhibitors

Example of an enzyme and its reaction?

Catalase converts H₂O₂ → H₂O + O₂

What do OIL RIG and pH rules stand for?

OIL RIG = Oxidation Is Lose, Reduction Is Gain; Acid = H⁺ donor, Base = H⁺ acceptor

What is a buffer? Give an example.

Stabilizes pH; Example: bicarbonate in blood