Comprehensive Study Guide: Foundations of Biology (Chapters 1–17)

Chapter 1 – Characteristics of Life and Scientific Inquiry

Characteristics of Life

• Order: Living organisms exhibit complex but ordered organization.

• Regulation (Homeostasis): Ability to maintain stable internal conditions (e.g., body temperature).

• Growth and Development: Organisms grow and develop according to inherited instructions.

• Energy Processing: Use of energy to power activities (e.g., metabolism).

• Response to Environment: Reacting to environmental stimuli.

• Reproduction: Ability to produce offspring.

• Evolutionary Adaptation: Populations evolve over generations.

Feedback Mechanisms

• Negative Feedback: A process that reduces the initial stimulus (e.g., regulation of blood glucose).

• Positive Feedback: A process that amplifies the initial stimulus (e.g., blood clotting).

Scientific Method (Steps)

1. Observation

2. Question

3. Hypothesis

4. Prediction

5. Experiment

6. Analysis

7. Conclusion

Example: Testing the effect of sunlight on plant growth using controlled experiments.

Chapter 2 – Chemical Context of Life

Subatomic Particles and Atomic Structure

• Proton: Positively charged particle in the nucleus.

• Neutron: Neutral particle in the nucleus.

• Electron: Negatively charged particle orbiting the nucleus.

• Atomic Number: Number of protons in an atom.

• Mass Number: Sum of protons and neutrons.

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

• Ions: Charged atoms; cations are positive, anions are negative.

Chemical Bonds

• Polar Covalent Bonds: Electrons shared unequally (e.g., H2O).

• Non-polar Covalent Bonds: Electrons shared equally (e.g., O2).

• Ionic Bonds: Transfer of electrons from one atom to another (e.g., NaCl).

• Hydrogen Bonds: Weak attraction between a hydrogen atom and an electronegative atom.

• Van der Waals Interactions: Weak, transient interactions due to fluctuating charges.

Chapter 3 – Water and Life

Properties of Water

• Cohesion: Water molecules stick together due to hydrogen bonding.

• High Specific Heat: Water resists temperature changes, stabilizing environments.

pH and Buffers

• pH Scale: Measures hydrogen ion concentration; ranges from 0 (acidic) to 14 (basic), 7 is neutral.

• Acids: Increase H+ concentration (pH < 7).

• Bases: Decrease H+ concentration (pH > 7).

• Buffers: Substances that minimize changes in pH.

Equation: $\mathrm{pH} = -\log_{10}[\mathrm{H}^+]$

Chapter 4 – Carbon and Molecular Diversity

Organic Molecules and Functional Groups

• Major Elements: Carbon (C), Hydrogen (H), Oxygen (O), Nitrogen (N), Phosphorus (P), Sulfur (S).

• Functional Groups:

  • Hydroxyl (-OH)

  • Carbonyl (C=O)

  • Carboxyl (-COOH)

  • Amino (-NH2)

  • Sulfhydryl (-SH)

  • Phosphate (-PO4)

  • Methyl (-CH3)

Example: Amino acids contain amino and carboxyl groups.

Chapter 5 – Structure and Function of Large Biological Molecules

Macromolecules

• Carbohydrates: Sugars and polymers of sugars; monomer = monosaccharide.

• Lipids: Hydrophobic molecules (fats, oils, steroids); not true polymers.

• Proteins: Polymers of amino acids; perform many cellular functions.

• Nucleic Acids: DNA and RNA; monomer = nucleotide.

Polymerization Reactions

• Dehydration Reaction: Joins monomers by removing water.

• Hydrolysis: Breaks polymers by adding water.

Hydrophobic vs. Hydrophilic

• Hydrophobic: Repels water (e.g., lipids).

• Hydrophilic: Attracts water (e.g., sugars).

Example: Triglyceride is a lipid formed from glycerol and three fatty acids.

Chapter 6 – A Tour of the Cell

Cellular Structures and Functions

• Nucleus: Contains genetic material (DNA).

• Mitochondria: Site of cellular respiration and ATP production.

• Ribosomes: Synthesize proteins.

• Vesicles: Transport materials within the cell.

• Endoplasmic Reticulum (ER):

  • Rough ER: Studded with ribosomes; synthesizes proteins.

  • Smooth ER: Synthesizes lipids, detoxifies chemicals.

• Golgi Apparatus: Modifies, sorts, and packages proteins and lipids.

• Lysosomes: Digestive organelles; break down macromolecules.

• Nucleolus: Site of ribosomal RNA synthesis.

• Cytoskeleton: Network of fibers (microtubules, microfilaments, intermediate filaments) for support and movement.

• Cilia and Flagella: Movement structures; cilia are short and numerous, flagella are longer and fewer. Both have a "9+2" arrangement of microtubules.

Pathway of Protein Synthesis

1. DNA (nucleus) → mRNA (transcription)

2. mRNA exits nucleus → ribosome (translation)

3. Protein enters ER → Golgi apparatus → vesicle → destination

Chapter 7 – Membrane Structure and Function

Cell Membrane Components and Characteristics

• Phospholipids: Form bilayer; hydrophilic heads, hydrophobic tails.

• Proteins: Integral and peripheral; involved in transport, signaling, etc.

• Carbohydrates: Cell recognition.

Transport Mechanisms

• Diffusion: Movement from high to low concentration.

• Osmosis: Diffusion of water across a membrane.

• Facilitated Transport: Uses membrane proteins for diffusion.

• Active Transport: Requires energy (ATP) to move substances against gradient.

• Endocytosis: Uptake of materials via vesicles.

• Pinocytosis: "Cell drinking"; uptake of fluids.

Tonicity

• Isotonic: Equal solute concentration inside and outside cell.

• Hypotonic: Lower solute concentration outside; cell swells.

• Hypertonic: Higher solute concentration outside; cell shrinks.

Chapter 8 – Introduction to Metabolism

Enzymes and Metabolic Pathways

• Enzyme: Biological catalyst that speeds up reactions.

• Substrate: Reactant acted upon by enzyme.

• Product: Result of enzymatic reaction.

• Cofactor: Non-protein helper (e.g., metal ion).

• Coenzyme: Organic cofactor (e.g., vitamins).

• Active Site: Region where substrate binds.

• Competitive Inhibitor: Binds active site, blocks substrate.

• Non-competitive Inhibitor: Binds elsewhere, changes enzyme shape.

Equation: $\text{E} + \text{S} \rightleftharpoons \text{ES} \rightarrow \text{E} + \text{P}$

Chapter 9 – Cellular Respiration and Fermentation

Metabolic Pathways

• Anabolic Pathways: Build complex molecules (require energy).

• Catabolic Pathways: Break down molecules (release energy).

ATP and Electron Carriers

• ATP (Adenosine Triphosphate): Main energy currency.

• NAD+/NADH, FAD/FADH2: Electron carriers.

Stages of Cellular Respiration

1. Glycolysis: Occurs in cytoplasm; glucose → pyruvate.

2. Krebs Cycle (Citric Acid Cycle): Occurs in mitochondrial matrix; completes glucose breakdown.

3. Electron Transport Chain & Chemiosmosis: Inner mitochondrial membrane; produces most ATP.

Fermentation: Anaerobic process; includes alcohol and lactic acid fermentation.

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

Substrate-level Phosphorylation: Direct transfer of phosphate to ADP.

ATP Synthase: Enzyme that makes ATP using proton gradient.

Location of Processes:

• Glycolysis: Cytoplasm

• Krebs Cycle: Mitochondrial matrix

• Electron Transport Chain: Inner mitochondrial membrane

Chapter 12 – The Cell Cycle and DNA

DNA vs. RNA

• DNA: Double-stranded, deoxyribose sugar, bases A, T, C, G.

• RNA: Single-stranded, ribose sugar, bases A, U, C, G.

Gene and Central Dogma

• Gene: Unit of heredity; sequence of DNA coding for a protein.

• Central Dogma: DNA → RNA → Protein

Cell Cycle Phases

• G1 Phase: Cell growth

• S Phase: DNA synthesis

• G2 Phase: Preparation for mitosis

Mitosis Phases (in order)

1. Prophase

2. Metaphase

3. Anaphase

4. Telophase

Chapter 13 – Meiosis and Sexual Life Cycles

Meiosis

• Reduces chromosome number by half; produces gametes.

• Phases (in order): Prophase I, Metaphase I, Anaphase I, Telophase I, Prophase II, Metaphase II, Anaphase II, Telophase II.

• Crossing Over: Exchange of genetic material between homologous chromosomes during Prophase I.

Meiosis vs. Mitosis

Feature	Mitosis	Meiosis
Number of Divisions	1	2
Number of Daughter Cells	2	4
Genetic Identity	Identical	Unique
Chromosome Number	Diploid	Haploid

Chapter 14 – Mendel and the Gene Idea

Genetics Vocabulary

• Allele: Alternative form of a gene.

• Homozygous: Two identical alleles.

• Heterozygous: Two different alleles.

• Dominant: Expressed allele in heterozygote.

• Recessive: Masked allele in heterozygote.

• Genotype: Genetic makeup.

• Phenotype: Observable traits.

Chapter 15 – Chromosomal Basis of Inheritance

Genetic Material Exchange

• Crossing Over: Exchange of genetic material between homologous chromosomes during meiosis increases genetic diversity.

Chapters 16/17 – Molecular Basis of Inheritance and Gene Expression

DNA Replication

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

Transcription and Translation

• Transcription: DNA → mRNA (in nucleus).

• Translation: mRNA → Protein (at ribosome).

• Codon: Three-nucleotide sequence on mRNA coding for an amino acid.

• Anticodon: Complementary sequence on tRNA.

Types of RNA

• mRNA (messenger RNA): Carries genetic code from DNA to ribosome.

• tRNA (transfer RNA): Brings amino acids to ribosome.

• rRNA (ribosomal RNA): Structural and catalytic component of ribosomes.

Mutations

• Missense Mutation: Changes one amino acid.

• Nonsense Mutation: Introduces a stop codon.

• Frameshift Mutation: Insertion or deletion shifts reading frame.

• Silent Mutation: No change in amino acid sequence.

Determining mRNA Sequence

• Use the DNA template strand to determine complementary mRNA sequence (A→U, T→A, C→G, G→C).

Example: DNA template: 3'-TAC GGA-5' → mRNA: 5'-AUG CCU-3'

Equation (Central Dogma): $\text{DNA} \xrightarrow{\text{transcription}} \text{RNA} \xrightarrow{\text{translation}} \text{Protein}$

Additional info: Chapters not listed (e.g., Ch. 18) are not included as per the study guide instructions.