Final

Chapter 1: Properties of Life

  • Independent variable = variable you change in an experiment

  • Dependent variable = variable you measure (results/response)

  • Hypothesis = a testable prediction (usually “If…then…” statement)

  • First step in research = observation

Chapter 2: Chemistry

  • Matter = anything that has mass and takes up space

  • Elements in organisms = mainly C, H, O, N, P, S

Subatomic particles:

  • Protons = positive charge, in nucleus

  • Neutrons = no charge, in nucleus

  • Electrons = negative charge, outside nucleus

Atoms:

  • Smallest unit of an element that retains its properties

Isotopes:

  • Same element, different number of neutrons

Chemical bonds:

  • Ionic bond = transfer of electrons

    • Cation = positive

    • Anion = negative

  • Covalent bond = sharing electrons

    • Polar covalent = unequal sharing (partial charges)

    • Nonpolar covalent = equal sharing

  • Hydrogen bond = weak attraction between polar molecules

Chapter 3: Water

  • Water is polar

  • Polarity leads to 4 properties:

1. Cohesion/Adhesion

  • Cohesion = water sticks to water

  • Adhesion = water sticks to other surfaces

2. High heat capacity

  • Water resists temperature change

3. Expansion when freezing

  • Ice is less dense than liquid water

4. Universal solvent

  • Solvent = dissolves substances

  • Solution = solvent + solute

Other key concepts:

  • Water dissociation: H₂O → H⁺ + OH⁻

  • pH scale: measures H⁺ concentration (0–14)

    • Low pH = acidic

    • 7 = neutral

    • High pH = basic

Chapter 4: Carbon

  • Carbon bonds with: H, O, N

  • Forms:

    • Linear chains

    • Rings

    • Branches

Isomers:

  • Structural isomers = different bonding arrangement

  • Cis/trans isomers = same bonds, different orientation

  • Enantiomers = mirror images

Functional groups:

  • Determine chemical properties (e.g. hydroxyl = polar, amino = basic, carboxyl = acidic, phosphate = energy-related)

Key ideas:

  • Shape determines function

  • ATP = energy currency

  • Hydrolysis of ATP = ATP → ADP + energy

Chapter 5: Macromolecules

Carbohydrates

  • Monomers: monosaccharides

    • Glucose, fructose, galactose

  • Disaccharides: sucrose, lactose, maltose

  • Polysaccharides:

    • Starch (plants)

    • Glycogen (animals)

    • Cellulose (plant cell walls)

Lipids

  • Built from fatty acids + glycerol

  • Types:

    • Triglycerides (fats)

    • Saturated = no double bonds (solid)

    • Unsaturated = double bonds (liquid)

    • Phospholipids = cell membranes

    • Steroids = cholesterol-based hormones

Proteins

  • Monomer: amino acids

  • Polymers:

    • Peptides → polypeptides → proteins

  • R group = determines amino acid identity and function

Reactions:

  • Dehydration synthesis = builds polymers (removes water)

  • Hydrolysis = breaks polymers (adds water)

  • Exergonic = releases energy

  • Endergonic = requires energy

DNA/RNA

  • Monomer = nucleotide

  • Components:

    • phosphate group

    • sugar (deoxyribose or ribose)

    • nitrogen base

Chapter 6: Cell

  • Organelle functions:

    • Nucleus = DNA control center

    • Ribosomes = protein synthesis

    • Mitochondria = ATP production

    • ER = protein/lipid transport

    • Golgi = packaging

    • Lysosomes = digestion

    • Cytoplasm = fluid interior

    • Cell membrane = controls entry/exit

Chapter 7: Cell Membrane

  • Phospholipid bilayer = hydrophilic heads + hydrophobic tails

Cholesterol:

  • Maintains membrane fluidity

Proteins:

  • Integral = embedded in membrane

  • Peripheral = surface proteins

Carbohydrates:

  • Glycoproteins = protein + sugar

  • Glycolipids = lipid + sugar

Transport:

  • Simple diffusion = no energy

  • Channels = ions pass

  • Transporters = facilitated diffusion

  • Pumps = ATP required

  • Aquaporins = water channels (osmosis)

Osmosis types:

  • Hypotonic = cell gains water

  • Hypertonic = cell loses water

  • Isotonic = no net change

Chapter 8: Metabolism

  • ATP = energy molecule

  • Reaction: Substrate + enzyme → product

Enzymes:

  • Proteins that speed up reactions

  • Active site = binding area

  • Enzyme-substrate complex = temporary binding

Factors affecting enzymes:

  • Temperature

  • pH

Inhibitors:

  • Competitive = blocks active site

  • Noncompetitive = changes enzyme shape

Helpers:

  • Cofactors = inorganic helpers (ions)

  • Coenzymes = organic helpers (vitamins)

Chapter 9: Cellular Respiration

  • Overall equation:

    • C₆H₁₂O₆ + O₂ → CO₂ + H₂O + ATP + heat

Stages:

  • Glycolysis:

    • glucose → pyruvate + ATP + NADH

  • Krebs cycle:

    • acetyl-CoA → CO₂ + NADH + FADH₂

  • Oxidative phosphorylation:

    • produces most ATP

Fermentation:

  • Alcohol fermentation

  • Lactic acid fermentation

  • Occurs without oxygen

Chapter 10: Photosynthesis

  • Equation:

    • CO₂ + H₂O + light → glucose + O₂

Light reactions:

  • Require light

  • Produce ATP, NADPH, O₂

Calvin cycle:

  • Does NOT require light directly

  • Produces glucose

Chapter 11: Cell Communication

  • Types:

    • Paracrine = local signaling

    • Synapse = neuron communication

    • Endocrine = hormones in bloodstream

Receptors:

  • Bind ligands (signals)

Types:

  • G-protein coupled receptors

  • Tyrosine kinase receptors

  • Ligand-gated ion channels

Signaling process:

  • Ligand = first messenger

  • Second messengers = cAMP, IP3, Ca²⁺

  • Amplification = signal gets stronger inside cell

Chapter 12: Cell Cycle

  • G1 → S → G2 → M

Key terms:

  • Homologous chromosomes = same genes, different origin

  • Sister chromatids = identical copies

  • Mitosis:

    • 2n → 2n (same chromosome number)

Chapter 13: Meiosis

  • 2n → n (gametes)

Genetic variation:

  • Crossing over

  • Independent assortment

  • Random fertilization

Genetics:

  • Homozygous = same alleles

  • Heterozygous = different alleles

  • Dominant = expressed trait

  • Recessive = masked trait

  • Codominance = both expressed equally

Chapter 15: Chromosomal Inheritance

  • Barr body = inactivated X chromosome

  • Y chromosome = determines male sex

  • X-linked traits = carried on X (e.g. color blindness)

  • Trisomy = extra chromosome (e.g. Down syndrome)

Chapters 16–18: Gene Expression

DNA Replication:

  • Leading strand = continuous

  • Lagging strand = fragments

  • Okazaki fragments = pieces on lagging strand

  • Enzymes:

    • Helicase = unwinds DNA

    • Primase = lays RNA primer

    • DNA polymerase = builds DNA

    • Ligase = connects fragments

    • Topoisomerase = relieves tension

    • SSB proteins = stabilize strands

Transcription:

  • DNA → RNA

Translation:

  • RNA → protein (ribosome + tRNA)

Codons:

  • 3-base RNA code for amino acids

Splicing:

  • Removes introns, keeps exons

Gene regulation:

  • Prokaryotes = operons

  • Eukaryotes:

    • DNA methylation = silences genes

    • Histone acetylation = activates genes

Chapter 19: Viruses

  • Virion = complete virus particle

  • Virus = genetic material + protein coat

Structure:

  • Capsid = protein shell

  • Capsomeres = protein subunits

  • Some have lipid envelope

Viral reproduction:

  • Lytic cycle:

    • virus replicates → cell bursts → dies

  • Lysogenic cycle:

    • viral DNA integrates into host DNA

    • cell survives initially

    • can switch to lytic later

Types:

  • dsDNA, ssDNA, dsRNA, ssRNA viruses

  • Reverse transcriptase:

    • RNA → DNA

AIDS:

  • Caused by HIV

  • Attacks immune system (CD4 T cells)