Unit 1: Chemistry of Life
1.1: Structure of Water and Hydrogen Bonding
✅ Water is a polar molecule due to the unequal sharing of electrons between
oxygen and hydrogen. ✅ Hydrogen bonds form between water molecules,
leading to unique properties:
● Cohesion (water sticks to itself, creating surface tension)
● Adhesion (water sticks to other surfaces, allowing capillary action)
● High specific heat (absorbs heat without drastic temperature changes)
● Universal solvent (dissolves many substances due to polarity)
Exam Tip: Be able to explain why ice floats and how water’s high specific heat
helps regulate Earth’s climate.
1.2: Elements of Life
✅ Carbon, hydrogen, oxygen, nitrogen (CHON) are the primary elements in
biological molecules. ✅ Organic molecules (carbohydrates, lipids, proteins,
nucleic acids) are essential for life. ✅ Carbon’s ability to form four covalent
bonds allows complex macromolecules to form.
Exam Tip: Expect a question on how carbon’s bonding properties contribute to
molecular diversity.
1.3: Introduction to Biological Macromolecules
✅ Macromolecules are built from monomers through dehydration
synthesis (removal of water). ✅ Macromolecules are broken down by
hydrolysis (addition of water).
Exam Tip: Be ready to analyze diagrams showing dehydration synthesis and
hydrolysis reactions.
1.4: Properties of Biological Macromolecules
✅ Carbohydrates - Provide quick energy; made of monosaccharides (e.g.,
glucose). ✅ Lipids - Store long-term energy; made of fatty acids and glycerol.
✅ Proteins - Build structures and speed up reactions (enzymes); made of
amino acids. ✅ Nucleic Acids - Store and transmit genetic info; made of
nucleotides (DNA & RNA).
Exam Tip: Know how structure affects function (e.g., why unsaturated fats are
liquid at room temperature).
1.5: Nucleic Acids
✅ DNA and RNA differ in structure:
● DNA: Double-stranded, deoxyribose sugar, contains thymine (T)
● RNA: Single-stranded, ribose sugar, contains uracil (U) ✅ Base pairing:
1.1: Structure of Water and Hydrogen Bonding
✅ Water is a polar molecule due to the unequal sharing of electrons between
oxygen and hydrogen. ✅ Hydrogen bonds form between water molecules,
leading to unique properties:
● Cohesion (water sticks to itself, creating surface tension)
● Adhesion (water sticks to other surfaces, allowing capillary action)
● High specific heat (absorbs heat without drastic temperature changes)
● Universal solvent (dissolves many substances due to polarity)
Exam Tip: Be able to explain why ice floats and how water’s high specific heat
helps regulate Earth’s climate.
1.2: Elements of Life
✅ Carbon, hydrogen, oxygen, nitrogen (CHON) are the primary elements in
biological molecules. ✅ Organic molecules (carbohydrates, lipids, proteins,
nucleic acids) are essential for life. ✅ Carbon’s ability to form four covalent
bonds allows complex macromolecules to form.
Exam Tip: Expect a question on how carbon’s bonding properties contribute to
molecular diversity.
1.3: Introduction to Biological Macromolecules
✅ Macromolecules are built from monomers through dehydration
synthesis (removal of water). ✅ Macromolecules are broken down by
hydrolysis (addition of water).
Exam Tip: Be ready to analyze diagrams showing dehydration synthesis and
hydrolysis reactions.
1.4: Properties of Biological Macromolecules
✅ Carbohydrates - Provide quick energy; made of monosaccharides (e.g.,
glucose). ✅ Lipids - Store long-term energy; made of fatty acids and glycerol.
✅ Proteins - Build structures and speed up reactions (enzymes); made of
amino acids. ✅ Nucleic Acids - Store and transmit genetic info; made of
nucleotides (DNA & RNA).
Exam Tip: Know how structure affects function (e.g., why unsaturated fats are
liquid at room temperature).
1.5: Nucleic Acids
✅ DNA and RNA differ in structure:
● DNA: Double-stranded, deoxyribose sugar, contains thymine (T)
● RNA: Single-stranded, ribose sugar, contains uracil (U) ✅ Base pairing:
