General Biology Study Guide: Chapters 1–17

Ch. 1 Introduction: Evolution & Foundations of Biology

Overview of Biology

• Flow of Energy within an Ecosystem: Energy enters ecosystems as sunlight, is converted by producers (plants) into chemical energy, and flows through consumers and decomposers.

• Scientific Method: A systematic approach to inquiry involving observation, hypothesis formation, experimentation, and analysis.

• Lab Example: Lab 1 typically introduces experimental design and observation skills.

Ch. 2 The Chemical Context of Life

Chemical Bonds and Water

• Chemical Bonds: Atoms form molecules via ionic, covalent, and hydrogen bonds.

• Properties of Water: Water's polarity leads to hydrogen bonding, giving rise to cohesion, adhesion, and high specific heat.

• Acids and Bases: Acids donate H+; bases accept H+. The pH scale measures hydrogen ion concentration.

• Example: Table salt (NaCl) forms via ionic bonding; water is a polar covalent molecule.

Ch. 3 Carbon & the Molecular Diversity of Life

Organic Molecules

• Structure of Sugars: Carbohydrates are composed of monosaccharides (simple sugars) that form polysaccharides.

• Structure of Amino Acids: Amino acids are the building blocks of proteins, each with a central carbon, amino group, carboxyl group, and variable R group.

• Example: Glucose (C6H12O6) is a common monosaccharide.

Ch. 4 A Tour of the Cell

Cell Structure and Function

• Cell Organelles: Eukaryotic cells contain membrane-bound organelles (nucleus, mitochondria, etc.), while prokaryotic cells do not.

• Functions: Organelles perform specialized functions (e.g., mitochondria for energy production).

• Eukaryotes vs. Prokaryotes: Eukaryotes have a nucleus and complex organelles; prokaryotes (bacteria, archaea) lack these structures.

Ch. 5 Membrane Transport and Cell Signaling

Plasma Membrane Structure and Function

• Fluid Mosaic Model: The plasma membrane is a dynamic structure of phospholipids and proteins.

• Transport Mechanisms: Passive transport (diffusion, osmosis) does not require energy; active transport requires ATP.

• Types of Proteins: Integral and peripheral proteins serve as channels, carriers, or receptors.

• Types of Signaling: Cells communicate via chemical signals (hormones, neurotransmitters).

• Lab Example: Dialysis tubing lab demonstrates selective permeability.

Ch. 6 Introduction to Metabolism

Metabolic Pathways and Energy

• Anabolic vs. Catabolic Processes: Anabolic pathways build molecules (require energy); catabolic pathways break down molecules (release energy).

• Enzyme Function: Enzymes lower activation energy, increasing reaction rates. They have specific substrates and active sites.

• ATP: Adenosine triphosphate is the cell's energy currency. ATP hydrolysis releases energy for cellular work.

• Lab Example: Potato enzyme lab explores enzyme activity.

• Equation: $\text{ATP} + \text{H}_2\text{O} \rightarrow \text{ADP} + \text{P}_i + \text{energy}$

Ch. 7 Cellular Respiration and Fermentation

Harvesting Chemical Energy

• Cellular Respiration: The process by which cells extract energy from glucose in the presence of oxygen.

• Stages: Glycolysis, Krebs cycle (citric acid cycle), and oxidative phosphorylation.

• Electron Carrier Molecules: NAD+ and FAD transport electrons to the electron transport chain.

• Fermentation: Anaerobic process producing ATP without oxygen.

• Lab Example: Cellular respiration lab investigates CO2 production.

• Equation: $\text{C}_6\text{H}_{12}\text{O}_6 + 6\text{O}_2 \rightarrow 6\text{CO}_2 + 6\text{H}_2\text{O} + \text{energy}$

Ch. 8 Photosynthesis

Converting Light to Chemical Energy

• Photosynthesis: Plants convert light energy into chemical energy (glucose).

• Light Reactions: Occur in the thylakoid membranes; produce ATP and NADPH.

• Calvin Cycle: Occurs in the stroma; uses ATP and NADPH to fix CO2 into sugars.

• Pigments: Chlorophyll a, chlorophyll b, and carotenoids absorb light at specific wavelengths.

• Lab Example: Photosynthesis lab measures oxygen production or starch formation.

• Equation: $6\text{CO}_2 + 6\text{H}_2\text{O} + \text{light energy} \rightarrow \text{C}_6\text{H}_{12}\text{O}_6 + 6\text{O}_2$

Ch. 9 The Cell Cycle

Cell Division and Regulation

• Phases of the Cell Cycle: Interphase (G1, S, G2) and M phase (mitosis and cytokinesis).

• Checkpoints: Control points where the cell assesses readiness to proceed.

• Mitosis: Division of the nucleus into two genetically identical daughter cells (prophase, metaphase, anaphase, telophase).

• Cytokinesis: Division of the cytoplasm.

• Lab Example: Mitosis lab uses slides and models to observe stages.

Ch. 10 Meiosis and Sexual Life Cycles

Genetic Variation through Sexual Reproduction

• Meiosis: Reduces chromosome number by half, producing four genetically unique gametes.

• Crossing Over: Homologous chromosomes exchange genetic material during prophase I, increasing genetic diversity.

• Comparison to Mitosis: Meiosis involves two divisions and produces non-identical cells; mitosis produces identical cells.

• Lab Example: Meiosis lab uses models to illustrate chromosome behavior.

Ch. 11 Mendel and the Gene Idea

Principles of Inheritance

• Punnett Squares: Visual tools for predicting genotype and phenotype ratios in offspring.

• Mendelian Laws: Law of segregation and law of independent assortment explain inheritance patterns.

• Probability: Used to predict outcomes of genetic crosses.

• Lab Example: Yeast lab demonstrates inheritance patterns.

Ch. 12 The Chromosomal Basis of Inheritance

Genes and Chromosomes

• Model Organisms: Drosophila (fruit fly) used to study inheritance.

• Sex Chromosomes: X and Y chromosomes determine sex; X-linked traits show unique inheritance patterns.

• Alterations of Chromosome Structure: Deletions, duplications, inversions, and translocations can cause genetic disorders.

• Aneuploidy: Abnormal chromosome number (e.g., Down syndrome, Turner syndrome).

Ch. 13 The Molecular Basis of Inheritance

DNA Structure and Replication

• DNA Structure: Double helix with antiparallel strands, complementary base pairing (A-T, G-C), and sugar-phosphate backbone.

• Semiconservative Replication: Each new DNA molecule consists of one old and one new strand.

• Enzymes in Replication: Helicase unwinds DNA, primase synthesizes RNA primers, DNA polymerase adds nucleotides, ligase joins fragments.

• Prokaryotic vs. Eukaryotic Replication: Prokaryotes have a single origin; eukaryotes have multiple origins.

• Lab Example: pGlo and gel electrophoresis labs demonstrate DNA manipulation.

Ch. 14 Gene Expression: From Gene to Protein

Transcription and Translation

• Central Dogma: Information flows from DNA to RNA to protein.

• Transcription: Synthesis of RNA from a DNA template; involves promoters, RNA polymerase, and regulatory sequences.

• Translation: mRNA is decoded by ribosomes to build a polypeptide chain; tRNA brings amino acids to the ribosome.

• Genetic Code: Triplet codons specify amino acids; universal and redundant.

• RNA Processing: Eukaryotic mRNA is modified by adding a 5' cap, poly-A tail, and splicing out introns.

• Lab Example: pGlo and qPCR labs illustrate gene expression analysis.

Ch. 16 Development, Stem Cells, and Cancer

Cell Differentiation and Disease

• Stem Cells: Undifferentiated cells with the potential to become various cell types.

• Cell Differentiation: Process by which cells become specialized in structure and function.

• Apoptosis: Programmed cell death, important for development and disease prevention.

• Lab Example: pGlo lab explores gene regulation and transformation.

Ch. 17 Viruses

Structure and Function of Viruses

• What is a Virus? An infectious particle consisting of genetic material (DNA or RNA) enclosed in a protein coat (capsid).

• Differences from Cells: Viruses lack cellular structure and metabolism; cannot reproduce independently.

• Structure: May include envelope, capsid, and genetic material.