Biology Study Guide: Cell Structure, Function, and More - PDF

**Chapter 1: Introduction to Biology** 1. **Atom**: The smallest unit of matter, composed of protons, neutrons, and electrons. 2. **Biology**: The scientific study of life and living organisms. 3. **Biosphere**: The global ecological system integrating all living beings and their inter...

**Chapter 1: Introduction to Biology** 1. **Atom**: The smallest unit of matter, composed of protons, neutrons, and electrons. 2. **Biology**: The scientific study of life and living organisms. 3. **Biosphere**: The global ecological system integrating all living beings and their interactions with Earth\'s environments. 4. **Cell**: The basic structural and functional unit of all living organisms. 5. **Community**: A group of interacting populations of different species in a shared habitat. 6. **Control**: A component of an experiment that remains constant to provide a baseline for comparison. 7. **Deductive Reasoning**: A logical approach where specific predictions are made from general principles. 8. **Descriptive Science**: Scientific research focused on observation and description rather than experimentation. 9. **Ecosystem**: A biological community interacting with its physical environment. 10. **Eukaryote**: Organisms whose cells contain a nucleus and membrane-bound organelles. 11. **Evolution**: The process of genetic change in populations over generations, leading to diversity. 12. **Falsifiable**: A hypothesis that can be empirically disproven through experimentation. 13. **Homeostasis**: The maintenance of stable internal conditions in an organism. 14. **Hypothesis**: A testable explanation for a scientific question. 15. **Hypothesis-Based Science**: Research driven by hypothesis formulation and testing. 16. **Inductive Reasoning**: Deriving general principles from specific observations. 17. **Macromolecule**: Large molecules like proteins, nucleic acids, carbohydrates, and lipids. 18. **Molecule**: Two or more atoms chemically bonded. 19. **Organ**: A structure composed of tissues performing a specific function. 20. **Organ System**: A group of organs working together for a major physiological function. 21. **Organelle**: Specialized structures within eukaryotic cells (e.g., mitochondria). 22. **Organism**: An individual living entity. 23. **Peer-Reviewed Article**: A scholarly publication evaluated by experts in the field. 24. **Population**: Members of the same species inhabiting a specific area. 25. **Prokaryote**: Unicellular organisms lacking a nucleus (e.g., bacteria). 26. **Science**: A systematic method to study the natural world through evidence. 27. **Scientific Law**: A description of a consistent natural phenomenon (e.g., gravity). 28. **Scientific Method**: A process of inquiry involving observation, hypothesis, experimentation, and conclusion. 29. **Scientific Theory**: A well-supported explanation of natural phenomena (e.g., evolution). 30. **Tissue**: A group of similar cells performing a specialized function. 31. **Variable**: A factor manipulated or measured in an experiment. **Chapter 3: Cell Structure and Function** 1. **Two Cell Types**: Prokaryotic (no nucleus, simple) and eukaryotic (nucleus, complex). Both have DNA, cytoplasm, and membranes; eukaryotes have organelles. 2. **Animal vs. Plant Cells**: Both share nuclei, mitochondria, ER, and Golgi. Plant cells have chloroplasts, cell walls, and large vacuoles; animal cells have lysosomes and centrioles. 3. **Organelles**: - **Nucleus**: Stores DNA. - **Rough ER**: Protein synthesis (ribosomes attached). - **Smooth ER**: Lipid synthesis and detoxification. - **Ribosomes**: Protein assembly. - **Golgi**: Modifies and packages molecules. - **Lysosomes**: Digestive enzymes. - **Peroxisomes**: Break down toxins. - **Vesicles/Vacuoles**: Storage/transport. - **Centrioles**: Aid cell division (animal cells). - **Chloroplasts**: Photosynthesis (plant cells). - **Mitochondria**: ATP production. - **Plasma Membrane**: Regulates transport. - **Cell Wall**: Structural support (plants). - **Plasmodesmata/Gap Junctions**: Cell communication. - **Cytoplasm**: Gel-like matrix. - **Nucleoid**: Prokaryotic DNA region. 4. **Cytoskeleton**: Maintains cell shape, enables movement, and transports materials. Microtubules guide organelle movement and separate chromosomes. 5. **Cilia vs. Flagella**: Both aid motility; cilia are short/hair-like, flagella are long/tail-like. 6. **Microscopes**: Light microscopes use visible light; electron microscopes use electrons for higher resolution. 7. **Endosymbiosis Theory**: Mitochondria and chloroplasts originated from engulfed prokaryotes. 8. **Fluid Mosaic Model**: Plasma membrane is a phospholipid bilayer with embedded proteins, cholesterol, and carbohydrates. 9. **Transport Terms**: - **Selective Permeability**: Controls substance passage. - **Passive Transport**: No energy (e.g., diffusion). - **Osmosis**: Water movement across membranes. - **Tonicity**: Solution's effect on cell volume. 10. **Diffusion Rate Factors**: Gradient, temperature, molecule size, and medium density. 11. **Active Transport**: Requires ATP to move substances against gradients. Electrochemical gradient combines chemical and charge differences. 12. **Tonicity Effects**: - **Isotonic**: No net water movement. Equal solute concentration to the reference solution, resulting in no net movement of water across the cell membrane. - **Hypotonic**: Cell swells (animal lyses; plant becomes turgid). Lower solute concentration than the reference solution, causing water to move into the cell, potentially causing swelling - **Hypertonic**: Cell shrinks (animal shrivels; plant plasmolyzes).\ Plants prefer hypotonic; animals require isotonic (osmoregulation). Higher solute concentration than the reference solution, causing water to move out of the cell if placed in this solution, leading to cell shrinkage. 13. **Exocytosis/Endocytosis**: Exocytosis expels materials; endocytosis (phagocytosis, pinocytosis, receptor-mediated) imports materials. **Chapter 4: How Cells Obtain Energy** 1. **Bioenergetics**: Energy flow in cells. **Metabolism**: Sum of cellular reactions. **Anabolic** (builds molecules) vs. **Catabolic** (breaks down molecules). 2. **Thermodynamics**: - **1st Law**: Energy conservation. - **2nd Law**: Entropy (disorder) increases. Heat disperses energy. 3. **Energy Types**: **Kinetic** (motion), **Potential** (stored). **Chemical energy** in bonds (e.g., glucose). 4. **Free Energy**: Usable energy. **Exergonic** releases energy; **Endergonic** absorbs it. 5. **Enzymes**: Lower activation energy. Substrate binds active site via induced fit. 6. **Inhibitors**: Competitive block active sites; noncompetitive alter enzyme shape. **Cofactors** (ions) and **coenzymes** (vitamins) assist enzymes. 7. **Feedback Inhibition**: Products regulate enzyme activity to prevent overproduction. 8. **ATP Structure**: Adenine, ribose, three phosphates. Hydrolysis releases energy (exergonic). Phosphorylation (ADP → ATP) is endergonic. 9. **Glycolysis**: Breaks glucose into pyruvate (2 ATP), occurs in cytoplasm (anaerobic). 10. **Citric Acid Cycle**: In mitochondrial matrix; produces ATP, NADH, FADH₂. **Oxidative Phosphorylation**: In inner membrane; uses ETC to make ATP (aerobic). 11. **Fermentation**: Anaerobic; produces 2 ATP. **Lactic Acid**: Muscle cells; **Alcohol**: Yeast. 12. **Non-Glucose Metabolism**: Carbs enter glycolysis; proteins yield amino acids; lipids split into glycerol/fatty acids. **Chapter 5: Photosynthesis** 1. **Autotrophs**: Produce food via photosynthesis (plants). **Heterotrophs**: Consume others (animals). 2. **Photosynthesis Equation**: 6CO₂ + 6H₂O + light → C₆H₁₂O₆ + 6O₂. Occurs in chloroplasts (thylakoids and stroma). 3. **Light Reactions**: In thylakoids; split H₂O, produce ATP/NADPH. **Calvin Cycle**: In stroma; fixes CO₂ into glucose. 4. **Wavelength**: Determines energy; shorter (violet) = more energy. Visible spectrum (380--750 nm). 5. **Interconnection**: Photosynthesis produces O₂/glucose, which cellular respiration uses, creating CO₂/H₂O for plants. Chloroplasts and mitochondria enable energy cycling. +-------+-------+-------+-------+-------+-------+-------+-------+-------+ | | C6H12 | 602 | 6H20 | 6CO2 | ATP | NADPH | FADH | ETC | | | O6 | | | | | | | | +=======+=======+=======+=======+=======+=======+=======+=======+=======+ | Glyco | Yes✔ | ✗ | ✗ | ✗ | \*sub | 2 | ✗ | 2 | | lysis | | | | | strat | | | molec | | | | | | | e | | | ules | | | | | | | level | | | of | | | | | | | \* | | | pyruv | | | | | | | | | | ate | | | | | | | 2 | | | (3C) | | | | | | | | | | | | | | | | | \*net | | | | | | | | | | produ | | | | | | | | | | ction | | | | | | | | | | \* | | | | +-------+-------+-------+-------+-------+-------+-------+-------+-------+ | Pyruv | ✗ | ✗ | ✗ | 2 | ✗ | 2 | ✗ | 2 | | ate | | | | | | | | molec | | Oxida | | | | | | | | ules | | tion2 | | | | | | | | of | | | | | | | | | | acety | | | | | | | | | | l-coA | | | | | | | | | | (2c) | +-------+-------+-------+-------+-------+-------+-------+-------+-------+ | Citri | ✗ | ✗ | ✗ | 4 | 2 | 6 | 2 | | | c | | | | | \*sub | | | | | Acid | | | | | strat | | | | | Cycle | | | | | e-lev | | | | | | | | | | el | | | | | | | | | | ATP | | | | | | | | | | synth | | | | | | | | | | esis\ | | | | | | | | | | * | | | | +-------+-------+-------+-------+-------+-------+-------+-------+-------+ | Elect | ✗ | ✔ | ✔ | ✗ | \*che | 30 | 4 | | | ron | | | | | miosm | | | | | trans | | | | | osis\ | | | | | port | | | | | *34 | | | | | chain | | | | | | | | | +-------+-------+-------+-------+-------+-------+-------+-------+-------+ Cellular respiration: C6H12O6 + 6O2 → → → 6H2O + 6CO2 +ATP Substrate -- level ATP synthesis -- enzymes that remake a phosphate from an intermediate molecule and attaches it to ADP to wake ATP Chemiosmosis -- requires the formation of a H+ gradient to make ATP - Utilizes the enzyme ATP synthase O2(oxygen) acts as the final electron acceptor in the electron transport chain