BIO 111 FINAL EXAM REVIEW CONCISE

Atoms and Elements

• Atom vs. Element: Atom is the smallest unit of matter; Element is a pure substance of one atom type. Essential elements like C, H, O, N are crucial for life.

• Subatomic Particles: Proton (p⁺: +1 charge, ~1 amu, nucleus), Neutron (n⁰: 0 charge, ~1 amu, nucleus), Electron (e⁻: -1 charge, negligible mass, orbitals; involved in reactions).

Atomic Number, Mass, & Particle Count

• Atomic Number (Z): Number of protons, defines element. Mass Number (A): Protons + neutrons (A=p++n0A=p++n0). Atomic mass is a weighted average of isotopes.

Isotopes vs. Ions

• Isotopes: Same element (Z), different neutrons (A), same chemical behavior, neutral. Ions: Atom/molecule with net charge (lost/gained e−e−); affects electrical/chemical properties.

Electron Shells & Reactivity

• Electron Shell: Regions electrons occupy. Valence Shell: Outermost occupied shell, determines reactivity. Atoms seek stability via bonding to achieve full/empty valence shells (Octet Rule).

Electronegativity & Polarity

• Electronegativity (EN): Atom’s attraction for shared electrons. Polarity: Unequal electron sharing due to differing EN (e.g., H₂O).

Types of Chemical Bonds

• Ionic: e−e− transfer. Covalent: Shared e−e− (non-polar: equal, polar: unequal). Hydrogen Bonds: Weak electrostatic attraction between δ⁺ H and δ⁻ EN atom; crucial in biology.

Formulas vs. Equations

• Molecular Formula: Composition (e.g., C6H12O6C6H12O6​). Chemical Equation: Reaction depiction (reactants → products).

Solutions & Solubility

• Solution: Homogeneous mixture. Hydrophilic: Polar/charged, soluble in water. Hydrophobic: Non-polar, insoluble in water.

Water: Properties & Significance

• Bonds: Intramolecular polar covalent, intermolecular hydrogen bonds. Cohesion: Water-water attraction (surface tension). Adhesion: Water-other polar surfaces attraction. Universal Solvent: Due to polarity and H-bonding. High Specific Heat: Moderates temperatures. Density Anomaly: Ice floats (denser structure than liquid water), vital for aquatic life.

pH and Hydrogen Ions

• pH: Measures [H+]. Acids (pH < 7, high [H+]), Bases (pH > 7, low [H+]). pH=−extlog[H+]pH=−extlog[H+]. Buffers: Stabilize pH, essential for homeostasis.

Organic vs Inorganic Molecules

• Organic: Contains C-H bonds (e.g., carbohydrates). Inorganic: Lacks C-H bonds (e.g., water).

Carbon and Functional Groups

• Carbon: Forms diverse compounds due to 4 valence electrons and moderate EN. Functional Groups: Confer specific chemical properties (e.g., Hydroxyl (-OH), Carboxyl (-COOH), Amino (-NH₂), Phosphate (-PO₄), Methyl (-CH₃)).

Macromolecules

• Dehydration Synthesis: Forms polymers by removing water. Hydrolysis: Breaks polymers by adding water.

• Biological Classification: Carbohydrates (energy, structure), Lipids (energy storage, membranes, signaling), Proteins (enzymes, structure, signaling; diverse from 20 amino acids), Nucleic Acids (genetic info storage/transfer; DNA/RNA).

Cell Theory

• Cells are life's fundamental unit, all organisms are cells, all cells arise from pre-existing cells.

Prokaryotic vs Eukaryotic Cells

• Prokaryotes: Smaller (0.1-5µm), older (3.5 bya), circular chromosome (nucleoid), no membrane-bound organelles. Structures: P. membrane, cell wall, ribosomes, capsule, flagella, pili.

• Eukaryotes: Larger (10-100µm), younger (1.5 bya), linear chromosomes (nucleus), membrane-bound organelles (e.g., chloroplasts, mitochondria, ER, Golgi, lysosomes, peroxisomes, vacuoles, cytoskeleton, centrosomes).

Plasma Membrane Structure and Functions

• Fluid Mosaic Model: Flexible phospholipid bilayer with embedded proteins. Selectively Semi-Permeable.

• Components: Phospholipids (barrier), Cholesterol (fluidity/stability), Membrane Proteins (transport, receptors).

Energy

• Energy: Ability to do work (kinetic/potential). Thermodynamics: 1st Law (conservation), 2nd Law (entropy increase). Reactions: Metabolism, anabolism, catabolism, endergonic, exergonic, oxidation, reduction.

• ATP: Adenine, ribose, three phosphates; stores energy in phosphate bonds; drives cellular work.

Enzymes

• Enzymes: Biological catalysts, lower activation energy. Have active sites, bind substrates, produce products. Affected by pH/temp; function in metabolic pathways; regulated by feedback.

Membrane Function

• Transport: Passive (no ATP, down gradient: simple/facilitated diffusion, osmosis, tonicity) and Active (ATP, against gradient, via pumps, bulk transport).

Photosynthesis

• Definition: Plants/algae/cyanobacteria use light energy to convert CO2CO2 and H2OH2O into glucose (C6H12O6C6H12O6​) and oxygen (O∗2O∗2). Endergonic, anabolic.

• Equation: 6CO2+6H2O+light energy→C6H12O6+6O26CO2+6H2O+light energy→C6H12O6+6O2

• Chloroplasts: Site of photosynthesis (Thylakoids for light reactions, Stroma for Calvin Cycle).

• Light Reactions: In thylakoids, convert light to ATP/NADPH, release O∗2O∗2.

• Carbon Reactions (Calvin Cycle): In stroma, use ATP/NADPH to fix CO∗2CO∗2 into glucose.

Cellular Respiration

• Aerobic Definition: Mitochondria break down glucose with oxygen to produce CO2CO2, H2OH2O, and ATP. Catabolic, exergonic.

• Equation: C6H12O6+6O2→6H2O+6CO2+ATPC6H12O6+6O2→6H2O+6CO2+ATP.

• Mitochondria: Energy production organelle with outer/inner membranes, intermembrane space, matrix.

Anaerobic Respiration & Fermentation

• Anaerobic Respiration: Uses electron acceptor other than oxygen, yields substantial ATP. Performed by obligate anaerobes.

• Fermentation: Anaerobic process, primarily glycolysis, recycles NADH to NAD+NAD+ to sustain ATP production. Less efficient than aerobic respiration. Sub-types: Lactic acid fermentation (forms lactate, in muscle cells) and Alcohol fermentation (forms ethanol + CO∗2CO∗2, in yeast).

Gene Expression

• Process: DNA oo RNA (Transcription, in nucleus/cytoplasm) oo Protein (Translation, on ribosomes). Governed by codons and tRNAs.

• Mutations: Changes in DNA sequence. Point mutations (substitution: silent, missense, nonsense) or Frameshift mutations (insertions/deletions).

• Gene Regulation: Controls expression. Epigenetics (heritable, non-sequence changes), Prokaryotic Operons (regulated gene clusters).

• Definitions: Gene (encodes product), Chromosome (condensed DNA), Genome (complete genetic material).

Cell Cycle & Mitosis

• Eukaryotic Cell Cycle: G1 oo S oo G2 oo M (Mitosis + Cytokinesis). Interphase (growth, DNA replication) leads to M Phase (nuclear and cytoplasmic division).

• DNA Replication: Semi-conservative, uses Helicase, Primase, DNA Polymerase, Ligase.

• Mitosis: Asexual division (2n→2n2n→2n), produces two identical diploid cells via Prophase, Prometaphase, Metaphase (alignment), Anaphase (sister chromatid separation), Telophase.

• Checkpoints: Crucial for integrity (G1, S, G2, M). Regulation: Growth factors, cyclins, CDKs, density-dependent inhibition.

• Cancer: Uncontrolled cell growth due to mutations in proto-oncogenes (become oncogenes), tumor suppressor genes, or proofreader genes. Involves angiogenesis, telomere issues, apoptosis evasion, immune evasion.

Meiosis & Genetic Diversity

• Meiosis: Sexual reproduction (2n→n2n→n), yields 4 unique haploid gametes, creates diversity.

• Meiosis I (Homologs Separate): Prophase I (synapsis, crossing over), Metaphase I (homolog alignment), Anaphase I (homolog separation). Produces 2 haploid cells with duplicated chromosomes.

• Meiosis II (Sister Chromatids Separate): Resembles mitosis, separating sister chromatids. Yields 4 unique haploid cells.

• Cytokinesis Differences: Oogenesis (unequal, 1 ovum + polar bodies), Spermatogenesis (equal, 4 sperm).

• Chromosomal Errors: Nondisjunction (failure to separate) leads to Aneuploidy (missing/extra chromosomes, e.g., Trisomy 21). Polyploidy (extra sets).

• Chromosome Counts: Diploid (2n2n=46) somatic cells, Haploid (nn=23) gametes. Zygote (2n2n) is fertilized egg.

Mendelian Genetics

• Mendel's Experiments: Pea plants, particulate inheritance (alleles as discrete units). Terminology: True breeding, carrier, genotype, phenotype, dominant/recessive alleles, homozygous/heterozygous, P/F1/F2 generations.

• Test Cross: Unknown dominant phenotype crossed with homozygous recessive to determine genotype.

• Punnett Squares: Predict offspring ratios (Monohybrid F2: 1:2:1 genotype, 3:1 phenotype; Dihybrid F2: 9:3:3:1 phenotype).

• Mendel’s Laws: Segregation (alleles separate in gametes) and Independent Assortment (genes on different chromosomes assort independently).

• Beyond Mendel: Incomplete dominance (blending), Codominance (both expressed), Linked traits (co-inherited), Sex-linked (on sex chromosomes), Multiple alleles, Polygenic inheritance (continuous traits), Environmental effects, X-inactivation, Pleiotropy (one gene, multiple traits), Epistasis (one gene modifies another).

Genetic Engineering & Biotechnology

• Genetic Engineering (GE): Direct DNA manipulation via recombinant DNA (rDNA). Biotechnology: Broader field using organisms.

• rDNA: DNA from ≥2 sources joined by restriction enzymes and DNA ligase. Transgenic Organism (GMO): Carries foreign rDNA.

• Key Tools: Plasmids (cloning vectors), Restriction enzymes (cut DNA), DNA ligase (joins DNA), PCR (amplifies DNA using Taq polymerase), Gel Electrophoresis (separates DNA by size), DNA probes (detect target DNA).

• Sequencing: Sanger method (uses dideoxynucleotides).

• DNA Profiling: Uses STRs for individual identification.

• Stem Cells: Undifferentiated, can self-renew/differentiate (Totipotent, Pluripotent, Adult/Multipotent).

• Cloning: Somatic Cell Nuclear Transfer (SCNT) to clone organisms (Dolly) or create tissues (therapeutic cloning).

• Gene Therapy/Editing: Modifies genes to treat disease. Gene silencing (reduces expression), Gene editing (alters sequence via CRISPR/Cas9, Prime Editor).

• Vaccines: Traditional (whole/weakened virus) vs. mRNA (delivers mRNA for viral protein, host cells produce antigen).