GENBIO1.pdf

Study Notes: Living and Nonliving Things 1. Classification Living Things (Biotic) Possess life and can adapt to their environment. Non-Living Things (Abiotic) Resources that may or may not be finite. 2. Characteristics of Living Things Growth and Development Growth: Measurable increase (size, height...

Study Notes: Living and Nonliving Things 1. Classification Living Things (Biotic) Possess life and can adapt to their environment. Non-Living Things (Abiotic) Resources that may or may not be finite. 2. Characteristics of Living Things Growth and Development Growth: Measurable increase (size, height, weight). Development: Gradual transformation (e.g., caterpillar to butterfly). Mitosis: Cell duplication aiding growth and tissue repair. Response to Stimuli Ability to react to environmental changes (light, temperature, sound, etc.). Example: Plants moving toward sunlight. Reproduction Sexual Reproduction: Involves two parents, genetically unique offspring, meiosis. Asexual Reproduction: Involves one parent, genetically identical offspring (binary fission, budding). Metabolism Chemical reactions within cells. Anabolic: Builds complex molecules (e.g., photosynthesis). Catabolic: Breaks down complex molecules (e.g., cellular respiration). DNA Presence Hereditary material in cells, crucial for reproduction and genetic continuity. Homeostasis Maintenance of stable internal environment despite external changes. Example: Body temperature regulation (shivering, sweating). Cellular Organization Structure and arrangement of components within cells. Eukaryotic cells have more complex structures than prokaryotic cells. Key Terms Biotic Factors: Living components of the environment. Abiotic Factors: Non-living components (e.g., water, minerals). Mitosis: Process of cell division for growth and repair. Meiosis: Cell division for sexual reproduction. Homeostasis: Stability in an organism's internal environment. Examples Growth: Increase in a plant's height over time. Response: A flower opening in response to sunlight. Reproduction: Bacteria dividing by binary fission. Metabolism: A plant converting sunlight into glucose. References for Further Study Growth and Development Differences: Edugage Characteristics of Life: Mr. Potter’s website DNA Basics: National Library of Medicine Homeostasis: Khan Academy Cellular Processes Review Notes Key Concepts Cell Division Definition: Process where a parent cell divides to form daughter cells. Importance: Essential for growth, repair, and reproduction of cells. Reasons for Cell Division Replacement of damaged or dead cells (e.g., healing wounds). Growth of organisms through the increase in cell number. Total Cells in the Human Body Approx. 37 trillion cells as an adult, starting from a single fertilized egg. Regulation of Cell Division Cyclins: Proteins that regulate the cell cycle and communicate division signals. Importance of regulation to prevent uncontrolled cell growth (e.g., cancer). Types of Cell Division Mitosis Purpose: Division of somatic (non-reproductive) cells. Outcome: Two genetically identical diploid daughter cells (same chromosome number as parent). Phases of Mitosis: Interphase: Preparation, nutrient gathering, and DNA replication. Mitosis Phases: Prophase, Prometaphase, Metaphase, Anaphase, Telophase, Cytokinesis. Meiosis Purpose: Division of reproductive cells (gametes). Outcome: Four genetically unique haploid daughter cells (half the chromosome number). Key Features: Crossing Over: Exchange of genetic material between homologous chromosomes during Meiosis I, leading to genetic diversity. Phases of Meiosis: Meiosis I: Reduces chromosome number, includes crossing over. Meiosis II: Further divides the cells without duplication of chromosomes. Other Cellular Processes Diffusion: Movement of molecules from high to low concentration. Active Transport: Movement against concentration gradient using energy (ATP). Passive Transport: Movement along concentration gradient without energy. Exocytosis: Process of expelling materials from a cell. Endocytosis: Process of engulfing materials into a cell. Osmosis: Diffusion of water across a selectively permeable membrane. Summary Mitosis is crucial for growth and repair. Meiosis is essential for genetic diversity and reproduction. Cellular Processes Review Notes Key Cellular Processes Diffusion Definition: Movement of molecules from an area of high concentration to an area of low concentration. Concentration Gradient: Difference in concentration between two areas; molecules naturally move down this gradient. Cell Membrane Role: Selectively permeable barrier that controls molecule movement, using channels or transporters. Active Transport Definition: Movement of molecules from an area of low concentration to an area of high concentration, requiring energy (ATP). Carrier Proteins: Proteins that assist in moving molecules against their gradient; often referred to as "pumps." Example: Sodium-potassium pump moves Na+ out of and K+ into cells, vital for nerve function. Facilitated Diffusion Definition: Diffusion of solutes through transport proteins; a passive process (no energy required). Transport Proteins: Channel Proteins: Allow rapid passage of ions/water. Gated Channel Proteins: Open in response to stimuli (chemical/electrical). Carrier Proteins: Bind and change shape to transport specific molecules. Ion Channels Definition: Specialized proteins that allow ions (Na+, K+, Ca2+, Cl-) to move across membranes; can be gated or always open. Vesicle Transport Processes Endocytosis Definition: Process of engulfing substances into the cell by folding the membrane around them. Types: Phagocytosis: "Cellular eating" - engulfs large particles. Pinocytosis: "Cellular drinking" - engulfs liquids and dissolved substances. Exocytosis Definition: Process of vesicles fusing with the plasma membrane to release contents outside the cell. Function: Important for exporting proteins, waste removal, and membrane recycling. Vocabulary Term Definition Active Transport Energy-requiring movement of substances across a membrane against their gradient. Endocytosis Vesicle transport that moves substances into a cell. Exocytosis Vesicle transport that moves substances out of a cell. Phagocytosis Engulfing solid particles by the cell. Pinocytosis Engulfing liquid substances by the cell. Diffusion Movement of molecules from high to low concentration. Carrier Protein Protein that facilitates the movement of molecules across a membrane. Sodium-Potassium Pump Active transport pump that exchanges Na+ and K+ ions across the cell membrane. Summary Diffusion and facilitated diffusion enable passive transport of substances down concentration gradients. Active transport requires energy to move substances against gradients, essential for maintaining cellular functions. Endocytosis and exocytosis allow for the transport of larger molecules and particles across the cell membrane. Facilitated Osmosis and Osmotic Effects Facilitated Osmosis Definition: The diffusion of water molecules across a selectively permeable membrane from an area of higher water concentration to an area of lower water concentration. Osmosis in Different Environments Saltwater Fish vs. Freshwater Fish: Saltwater Fish: Cells are isotonic with seawater. In freshwater, water enters the cells, causing them to swell and potentially burst. Freshwater Fish: In saltwater, water leaves the cells, leading to dehydration and death. Key Concepts in Osmosis Solutions: Hypertonic: Higher solute concentration (lower water concentration). Hypotonic: Lower solute concentration (higher water concentration). Isotonic: Equal solute concentration. Cell Response to Solutions: Hypertonic Solution: Water moves out of the cell, causing it to shrivel (plasmolysis in plant cells). Hypotonic Solution: Water moves into the cell, causing it to swell and potentially burst (lysis in animal cells; turgid in plant cells). Isotonic Solution: No net movement of water; cell maintains normal shape. Osmotic Pressure Definition: The pressure exerted by water entering a cell, crucial for maintaining turgor in plant cells. Turgidity: A plant cell in a hypotonic environment becomes turgid due to osmotic pressure against the cell wall. Controlling Osmosis Contractile Vacuole: Organisms in hypotonic environments (e.g., freshwater protists) use these structures to expel excess water, preventing lysis. Differences Between Plant and Animal Cells Cell Wall: Present in plant cells; absent in animal cells. Shape: Plant cells are generally rectangular and fixed; animal cells are round and irregular. Chloroplasts: Only present in plant cells for photosynthesis. Summary Osmosis is critical for maintaining cellular homeostasis, allowing water to move in and out of cells depending on solute concentrations. Plant cells thrive in hypotonic environments, while animal cells require isotonic conditions to avoid osmotic stress. Introduction to Microorganisms Microorganisms are tiny, mostly unicellular organisms that cannot be seen with the naked eye. They are classified into four main groups: Bacteria: Prokaryotic, unicellular organisms. Fungi: Includes molds and yeasts. Protozoa: Single-celled eukaryotes. Viruses: Non-cellular entities that infect host cells. Bacteria Characteristics Shape: Can be spherical, rod-shaped, or spiral. Size: Micrometers in length; a gram of soil can contain around 40 million bacteria. Structure Capsule: Protective layer, prevents drying and phagocytosis. Cell Wall: Composed of peptidoglycan, providing shape and protection. Plasma Membrane: Controls permeability and energy generation. Cytoplasm: Gel-like substance where metabolic processes occur. DNA: Genetic material located in the cytoplasm. Ribosomes: Site of protein synthesis. Flagellum: Used for movement. Pili: Hair-like structures for attachment and genetic exchange. Nutrition Heterotrophic: Obtain energy by consuming organic material. Autotrophic: Produce their own food via photosynthesis or chemosynthesis. Habitats Found in diverse environments: soil, water, extreme conditions (hot springs, deep ocean vents). Reproduction Binary Fission: Asexual reproduction resulting in two identical cells. Genetic Transfer: Methods include conjugation, transformation, and transduction. Spores: Resistant forms that survive harsh conditions. Fungi Major Groups Multicellular Filamentous Molds: Made of hyphae forming a mycelium. They secrete enzymes to digest organic matter. Macroscopic Filamentous Fungi: Produce visible fruiting bodies (mushrooms) that contain spores. Yeasts: Single-celled fungi that reproduce by budding. Functions Play essential roles in decomposition, nutrient cycling, and have applications in food production (e.g., bread, brewing). Some species, like Candida, can cause infections, particularly in immunocompromised individuals. Summary Microorganisms, including bacteria and fungi, are vital components of ecosystems, involved in processes ranging from decomposition to food production. They exhibit diverse structures, reproductive methods, and habitats, showcasing their adaptability and significance in both natural and human-influenced environments. Protozoans Protozoa are single-celled microscopic animals, including groups such as flagellates, ciliates, and sporozoans. Examples include Amoeba, Paramecium, Euglena, and Plasmodium. Characteristics Diversity: Protozoans come in various shapes and sizes, with Amoeba being shapeshifting, while Paramecium has a fixed structure. Habitat: They thrive in moist environments, including freshwater, marine habitats, and soil. Movement: They are motile and can move by: Cilia: Tiny hair-like structures that create a rowing motion. Flagella: Long, whip-like structures for propulsion. Amoeboid Movement: Using pseudopodia, they extend their cytoplasm to move. Example: Stentor is a trumpet-shaped protozoan that uses cilia to capture food. Viruses Viruses are unique entities that contain nucleic acid but lack the machinery to replicate independently, categorizing them on the border between living and non-living. Characteristics Size: Typically range from 0.02 to 0.3 micrometers. Structure: Consists of a nucleic acid core (RNA or DNA) surrounded by a protein coat (capsid). Some have an additional lipid envelope with spike proteins for host recognition. Classification Viruses are classified based on: Type of nucleic acid (single- or double-stranded). Presence of a viral envelope. Mode of replication (e.g., DNA viruses replicate in the nucleus, RNA viruses in the cytoplasm). Infection Mechanism Transmission: Viruses can spread through: Direct Contact: Kissing, biting, or sexual intercourse. Indirect Contact: Contaminated objects. Common Vehicle: Contaminated food or water. Airborne Transmission: Inhalation of respiratory droplets. Life Cycle Lytic Cycle: Virus enters a host, replicates, and causes the host cell to burst, releasing new viruses. Lysogenic Cycle: Viral DNA integrates into the host genome and is replicated with the host's DNA during cell division. Related Microorganism Information Vaccines Biological preparations that provide immunity against diseases, primarily for viral infections (e.g., Polio, Influenza, Rabies). Antibiotics Compounds that inhibit or kill bacteria, used to treat bacterial infections. Pathogens Microorganisms that cause disease, including bacteria, protozoa, and viruses. Carrier An individual infected with a pathogen but not showing symptoms, capable of spreading the disease. Vector An organism that transmits pathogens between hosts, such as mosquitoes that spread dengue and malaria. Airborne Diseases Diseases that spread through the air, like influenza. Waterborne Diseases Diseases transmitted through contaminated water, such as typhoid. Key Topics in Nutrition and Health Conditions 1. Macronutrients Overview Lipids: Function: Provide energy, store energy, and form cell membranes. Structure: Composed of fatty acids and glycerol; includes saturated and unsaturated fats. Proteins: Function: Build and repair tissues, serve as enzymes and hormones. Structure: Made of amino acids; the sequence and structure determine function. Carbohydrates: Function: Primary energy source for the body. Types: Simple (sugars) vs. complex (starches and fibers). Nucleic Acids: Function: Store and transmit genetic information (DNA and RNA). 2. Nutritional Needs and Health Conditions Lactose Intolerance: Body's inability to digest lactose leading to gastrointestinal issues. Recommended Diet: Lactose-free alternatives (almond milk, lactose-free yogurt). Type 2 Diabetes: Impaired glucose metabolism; risk of high blood sugar. Recommended Diet: Low glycemic index foods, balanced carbs, fiber-rich foods. Atherosclerosis: Build-up of plaque in arteries; risk factors include high cholesterol. Recommended Diet: Low saturated fats, increased fiber, omega-3 fatty acids (fish). Osteoporosis: Thinning of bones; risk of fractures. Recommended Diet: High in calcium and vitamin D (dairy alternatives, leafy greens). Kidney Stones: Mineral buildup in the kidneys leading to stone formation. Recommended Diet: Hydration, limited sodium, oxalate-rich foods. Gout: Elevated uric acid levels causing joint pain. Recommended Diet: Low purine foods (avoid red meats, certain fish). Phenylketonuria (PKU): Inability to metabolize phenylalanine leading to neurological issues. Recommended Diet: Low-protein foods, special formulas low in phenylalanine. 3. Understanding Protein Structure and Function Primary Structure: Sequence of amino acids. Secondary Structure: Folding into alpha-helices or beta-sheets. Tertiary Structure: 3D shape formed by interactions among R groups. Quaternary Structure: Assembly of multiple polypeptide chains. 4. Energy Content of Nutrients Carbohydrates: Typically provide 4 calories per gram. Proteins: Provide 4 calories per gram, but are less efficient energy sources. Lipids: Provide 9 calories per gram, making them more energy-dense. 5. Amino Acids and Protein Folding Properties of Amino Acids: Side chains (R groups) determine solubility, charge, and interaction with other molecules. Folding Mechanism: Driven by hydrophobic and hydrophilic interactions, ionic bonds, and disulfide bridges.