General Biology: Core Concepts and Study Guide (Chapters 1–14)

Study Guide - Smart Notes

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Evolution: The process by which populations of organisms change over generations through variations in traits and natural selection.
Unity and Diversity: All living things share common characteristics (unity) but also display a wide variety of forms and functions (diversity).
Scientific Process: Involves observation, hypothesis formation, experimentation, and analysis to understand natural phenomena.
Diversity and Scientific Progress: Collaboration among scientists with diverse backgrounds enhances creativity and advances scientific knowledge.
Example: The theory of evolution by natural selection, proposed by Charles Darwin, unified biology by explaining both the similarities and differences among organisms.

Hydrogen Bonding: Weak bonds between the slightly positive hydrogen atom of one water molecule and the slightly negative oxygen atom of another, resulting from water's polarity.
Importance of Water: Water's properties (cohesion, adhesion, high specific heat, solvent abilities) are essential for life.
Hydrogen Bonding and Life: Hydrogen bonds contribute to water's unique properties, such as temperature regulation and solvent capabilities, which are vital for biological processes.
Example: Water's ability to dissolve a wide range of substances makes it an excellent medium for cellular reactions.

Organic Compounds: Molecules containing carbon atoms bonded to hydrogen and other elements; form the basis of life.
Carbon's Versatility: Carbon can form four covalent bonds, allowing for a variety of molecular structures (chains, rings, branches).
Functional Groups: Specific groups of atoms (e.g., hydroxyl, carboxyl, amino, phosphate) that confer distinct chemical properties to organic molecules.
Example: The presence of a carboxyl group (-COOH) makes a molecule acidic, as seen in amino acids.

Polymers: Large molecules made by joining many smaller units (monomers) through dehydration synthesis; broken down by hydrolysis.
Carbohydrates: Include simple sugars (monosaccharides) and complex carbohydrates (polysaccharides); provide energy and structural support.
Lipids: Hydrophobic molecules such as fats, phospholipids, and steroids; important for energy storage and membrane structure.
Proteins: Polymers of amino acids; perform a wide range of functions including catalysis (enzymes), structure, and transport.
Nucleic Acids: DNA and RNA; store and transmit genetic information.
DNA Sequencing: Modern techniques allow rapid sequencing of DNA, advancing genetics and biotechnology.
Example: Enzymes are proteins that speed up chemical reactions in cells.

Microscopy and Biochemistry: Techniques such as light and electron microscopy reveal cell structure; cell fractionation isolates organelles for study.
Prokaryotic vs. Eukaryotic Cells: Prokaryotes lack a nucleus and membrane-bound organelles; eukaryotes have both.
Organelles: Structures such as the nucleus, mitochondria, and ribosomes perform specialized functions.
Endomembrane System: Includes the endoplasmic reticulum, Golgi apparatus, lysosomes, and vesicles; involved in synthesis and transport of biomolecules.
Mitochondria and Chloroplasts: Sites of cellular respiration and photosynthesis, respectively; contain their own DNA.
Cytoskeleton: Network of protein fibers (microtubules, microfilaments, intermediate filaments) that provide structural support and facilitate movement.
Cell Wall and Extracellular Matrix: Provide additional support and protection in plant and animal cells.
Example: Mitochondria generate ATP through cellular respiration.

Fluid Mosaic Model: Describes the cell membrane as a flexible layer made of phospholipids with embedded proteins.
Selective Permeability: Membranes allow some substances to pass more easily than others.
Transport Mechanisms: Include diffusion, osmosis, facilitated diffusion (passive), and active transport (requires energy).
Bulk Transport: Endocytosis and exocytosis move large materials across the membrane.
Example: Glucose enters cells via facilitated diffusion through a specific transporter protein.

Catabolic Pathways: Break down molecules to release energy, often involving redox reactions.
Glycolysis: The breakdown of glucose into pyruvate, producing ATP and NADH.
Citric Acid Cycle: Completes the breakdown of glucose, generating more ATP, NADH, and FADH2.
Oxidative Phosphorylation: Uses the electron transport chain and chemiosmosis to produce ATP.
Fermentation: Anaerobic process that allows ATP production without oxygen.
Equation:
Example: Yeast cells perform alcoholic fermentation, producing ethanol and CO2.

Mitosis: Division of the nucleus resulting in two genetically identical daughter cells; includes prophase, metaphase, anaphase, and telophase.
Cytokinesis: Division of the cytoplasm, completing cell division.
Cell Cycle Control: Checkpoints (G1, G2, M) regulate progression through the cell cycle.
Example: The G1 checkpoint ensures the cell is ready for DNA synthesis.

Meiosis: Cell division that reduces chromosome number by half, producing gametes (sperm and eggs).
Fertilization: Fusion of gametes restores the diploid number.
Stages of Meiosis: Meiosis I (homologous chromosomes separate) and Meiosis II (sister chromatids separate).
Genetic Variation: Crossing over and independent assortment during meiosis increase genetic diversity.
Example: Sexual reproduction results in offspring with unique combinations of genes.

Mendel's Laws: Law of Segregation (alleles separate during gamete formation) and Law of Independent Assortment (genes for different traits assort independently).
Probability in Genetics: Used to predict the outcomes of genetic crosses (e.g., Punnett squares).
Complex Inheritance: Includes incomplete dominance, codominance, polygenic inheritance, and environmental effects.
Human Genetics: Pedigree analysis helps track inheritance patterns in families.
Example: Cystic fibrosis is inherited as a recessive trait.