Ch. 1 - Evolution, the Themes of Biology, and Scientific Inquiry

Key Terms

• Biology: The scientific study of life and living organisms.

• Eukaryotic cell: Cells with a nucleus and membrane-bound organelles.

• Prokaryotic cell: Cells lacking a nucleus; includes bacteria and archaea.

• Producers: Organisms that synthesize their own food (e.g., plants via photosynthesis).

• Consumers: Organisms that obtain energy by eating other organisms.

• Taxonomy: The science of classifying organisms.

• Natural selection: The process by which organisms better adapted to their environment tend to survive and reproduce.

• Inductive reasoning: Making generalizations based on specific observations.

• Deductive reasoning: Making predictions based on general principles.

• Hypothesis: A testable explanation for an observation.

• Theory: A broad explanation supported by a large body of evidence.

Concepts

• Properties of Life: Organization, energy use, response to environment, growth, reproduction, regulation, evolutionary adaptation.

• Levels of Life: Molecule → Organelle → Cell → Tissue → Organ → Organism → Population → Community → Ecosystem → Biosphere.

• Basic Unit of Life: The cell is the fundamental unit of structure and function.

• Information Molecule: DNA stores genetic information.

• Energy Use: Living things use energy for growth, maintenance, and reproduction.

• Three Domains: Bacteria, Archaea, Eukarya.

• Similarities: All living things share DNA, cellular structure, and metabolic pathways.

• Differences: Variations in cell type, structure, and function.

• Evolution: Change in populations over time; explains diversity and unity of life.

• Charles Darwin: Developed the theory of evolution by natural selection.

• Natural Selection: Individuals with advantageous traits survive and reproduce.

• Science: Systematic study based on observation and experimentation.

• Scientific Process: Based on evidence, logic, and repeatability.

• Scientific Method Outline: Observation → Question → Hypothesis → Experiment → Analysis → Conclusion.

Ch. 2 - The Chemical Context of Life

Key Terms

• Matter: Anything that has mass and occupies space.

• Element: A substance that cannot be broken down by chemical means.

• Compound: A substance made of two or more elements in a fixed ratio.

• Atom: The smallest unit of an element.

• Atomic number: Number of protons in an atom.

• Mass number: Number of protons plus neutrons.

• Isotope: Atoms of the same element with different numbers of neutrons.

• Electron shell: Energy levels where electrons reside.

• Valence electrons: Electrons in the outermost shell; involved in bonding.

• Molecule: Two or more atoms bonded together.

• Molecular formula: Shows the types and numbers of atoms in a molecule.

• Electronegativity: Atom's ability to attract electrons.

• Ion: Charged atom or molecule.

• Cation: Positively charged ion.

• Anion: Negatively charged ion.

• Reactant: Starting material in a chemical reaction.

• Product: Resulting material from a chemical reaction.

Concepts

• Four Most Common Elements: Carbon (C), Hydrogen (H), Oxygen (O), Nitrogen (N).

• Trace Elements: Required in small amounts (e.g., iron, iodine).

• Atom Structure: Nucleus (protons, neutrons) surrounded by electrons.

• Electron Distribution: Electrons fill shells; stability achieved with full valence shell.

• Chemical Bonds: Forces holding atoms together.

• Types of Bonds:

  • Covalent: Sharing electrons; single, double, polar (unequal sharing), nonpolar (equal sharing).

  • Ionic: Transfer of electrons; forms ions.

  • Hydrogen: Weak attraction between H and electronegative atom.

  • Van der Waals: Weak, transient interactions between molecules.

• Molecule Shape: Determines function and interactions.

• Chemical Reactions: Rearrangement of atoms; reactants → products.

Ch. 3 - Water and Life

Key Terms

• Water: Essential molecule for life; chemical formula H2O.

• Polar: Molecule with uneven charge distribution.

• Hydrogen bonds: Weak bonds between water molecules.

• Cohesion: Water molecules stick together.

• Adhesion: Water molecules stick to other surfaces.

• Surface tension: Measure of how difficult it is to break the surface of water.

• Calorie: Unit of energy; amount needed to raise 1g water by 1°C.

• Specific heat: Amount of heat needed to change temperature of 1g substance by 1°C.

• Evaporative cooling: Loss of heat as water evaporates.

• Solution: Homogeneous mixture; solvent dissolves solute.

• Aqueous solution: Solution where water is the solvent.

• Hydrophobic: Repels water.

• Hydrophilic: Attracts water.

• Molarity: Concentration; moles of solute per liter of solution.

Concepts

• Four Properties of Water:

  1. Cohesion and adhesion

  2. Moderation of temperature (high specific heat, evaporative cooling)

  3. Expansion upon freezing

  4. Versatility as a solvent

• Importance to Life: Water's properties support life processes (e.g., transport, temperature regulation).

• Acids: Substances that increase H+ concentration.

• Bases: Substances that decrease H+ concentration.

• pH Scale: Measures acidity; ranges from 0 (acidic) to 14 (basic). Formula:

• Buffer: Substance that minimizes changes in pH.

Ch. 4 - Carbon and the Molecular Diversity of Life

Key Terms

• Organic chemistry: Study of carbon-containing compounds.

• Organic compounds: Molecules with carbon atoms.

• Hydrocarbon: Compounds of only carbon and hydrogen.

• Isomer: Molecules with same formula but different structures.

• Enantiomer: Mirror-image isomers.

• Functional group: Specific group of atoms affecting molecule's properties.

Concepts

• Carbon's Versatility: Carbon can form four covalent bonds, enabling diverse molecules.

• Carbon Skeletons: Vary in length, branching, rings, and double bonds.

• Functional Groups: Determine chemical reactivity and properties of organic molecules.

• Seven Functional Groups: Hydroxyl, Carbonyl, Carboxyl, Amino, Sulfhydryl, Phosphate, Methyl.

Ch. 5 - The Structure and Function of Large Biological Molecules

Key Terms

• Macromolecule/polymer: Large molecule made of repeating units (monomers).

• Monomer: Small building block of polymers.

• Dehydration reaction: Joins monomers by removing water.

• Hydrolysis reaction: Breaks polymers by adding water.

• Monosaccharide: Simple sugar (e.g., glucose).

• Disaccharide: Two monosaccharides joined (e.g., sucrose).

• Glycosidic linkage: Bond between sugars.

• Polysaccharide: Many sugars joined (e.g., starch, cellulose).

• Fatty acid: Hydrocarbon chain with carboxyl group.

• Ester linkage: Bond in fats between glycerol and fatty acids.

• Triglyceride: Three fatty acids linked to glycerol.

• Saturated/unsaturated fats: Saturated have no double bonds; unsaturated have double bonds.

• Phospholipid: Major component of cell membranes.

• Steroid: Lipid with four fused rings (e.g., cholesterol).

• Enzyme: Protein that speeds up reactions.

• Amino acid: Building block of proteins.

• Polypeptide: Chain of amino acids.

• Denaturation: Loss of protein structure and function.

• Nucleotide: Building block of nucleic acids.

• Polynucleotide: Chain of nucleotides.

• Purine/pyrimidine: Types of nitrogenous bases.

• Phosphodiester linkage: Bond in nucleic acids.

• Double helix: Structure of DNA.

• Gene expression: Process by which information in DNA directs protein synthesis.

Concepts

• Four Main Classes of Organic Compounds:

  • Carbohydrates

  • Lipids

  • Proteins

  • Nucleic acids

• Polymers: Carbohydrates, proteins, nucleic acids are polymers; lipids are not true polymers.

• Functions, Structure, Examples:

  • Carbohydrates: Energy storage, structural support; e.g., glucose, starch, cellulose.

  • Lipids: Energy storage, membranes, hormones; e.g., fats, phospholipids, steroids.

  • Proteins: Enzymes, structure, transport; e.g., hemoglobin, collagen.

  • Nucleic acids: Information storage; e.g., DNA, RNA.

• Protein Structure:

  1. Primary: Sequence of amino acids

  2. Secondary: Alpha helix, beta sheet (hydrogen bonds)

  3. Tertiary: 3D folding (interactions among side chains)

  4. Quaternary: Multiple polypeptides

• Importance of Protein Shape: Determines function; denaturation disrupts activity.

• DNA vs. RNA Structure: DNA is double-stranded, RNA is single-stranded; different sugars and bases.

• Base Pairing: DNA: A-T, G-C; RNA: A-U, G-C.

• Bonds in DNA: Hydrogen bonds hold base pairs together.

Table: Comparison of Organic Molecule Classes

Example: Dehydration and Hydrolysis Reactions

• Dehydration: Joins monomers; releases water.

• Hydrolysis: Breaks polymers; adds water.

Additional info: Academic context and explanations were added to expand brief study guide points into full, self-contained notes suitable for exam preparation.