Science Notes PDF

Summary of Pages 6-30 Three Domains of Science 1.​ Science as a Way of Knowing (Scientific Inquiry)​ ○​ Relies on evidence, explains and predicts phenomena, and avoids bias. ○​ Produces scientific knowledge, including facts, concepts, theories, and laws. 2.​ Scien...

Summary of Pages 6-30 Three Domains of Science 1.​ Science as a Way of Knowing (Scientific Inquiry)​ ○​ Relies on evidence, explains and predicts phenomena, and avoids bias. ○​ Produces scientific knowledge, including facts, concepts, theories, and laws. 2.​ Science as a Way of Doing (Scientific Enterprise)​ ○​ Organized into content disciplines like biology, chemistry, and physics. ○​ Uses flexible, iterative methods such as observation, experimentation, and inference. 3.​ Science as a Way of Looking (Scientific Worldview)​ ○​ Views scientific knowledge as changeable, the universe as understandable, and acknowledges science's limitations. ○​ Examines the individual and social dimensions of scientific work. Scientific Skills and Attitudes: ​ Traits like intellectual honesty, objectivity, open-mindedness, critical thinking, and curiosity support scientific endeavors. Measurements ​ Units: Uses the International System (SI) for standards (meters, kilograms, seconds, etc.). ​ Accuracy vs. Precision: Accuracy is closeness to the true value; precision is the consistency of repeated measurements. ​ Significant Figures: Indicate measurement reliability. ​ Tools: Instruments like rulers, balances, and thermometers ensure precision and accuracy. Biomolecules 1.​ Carbohydrates​ ○​ Monosaccharides: Simple sugars like glucose, fructose, and galactose. ○​ Disaccharides: Formed from two monosaccharides (e.g., sucrose, lactose).  ○​ Polysaccharides: Complex sugars like starch, glycogen, and cellulose. 2.​ Proteins​ ○​ Made of amino acids with diverse functions, including enzymes, structural components, and antibodies. 3.​ Lipids​ ○​ Includes fats, oils, phospholipids, and steroids. ○​ Functions: Energy storage, cell membranes, and signaling. Atwater System ​ Estimates caloric value of foods: ○​ Carbohydrates and proteins: 4 kcal/g ○​ Lipids: 9 kcal/g ○​ Alcohol: 7 kcal/g ​ Formula: Multiply the gram quantity of each nutrient by its respective kcal value. Data Tables and Graphs ​ Types of Graphs: ○​ Pie Graphs: Represent parts of a whole. ○​ Bar Graphs: Compare quantities across categories. ○​ Line Graphs: Show trends over time. ​ Key Features: Titles, axis labels, legends, and scales ensure clarity and accuracy. Fundamental vs. Derived Quantities ​ Fundamental Quantities: Basic units like length, mass, and time (e.g., meters, kilograms, seconds). ​ Derived Quantities: Calculated from fundamental quantities (e.g., area, volume, speed, force). The Cell Theory Overview The Cell Theory is a foundational concept in biology, explaining the structure and function of cells as the building blocks of life. Key Contributors to the Cell Theory ​ Robert Hooke (1665) ○​ Coined the term "cell" after observing cork under a microscope. ○​ Noted structures resembling small rooms, called "cellulae" (Latin for "small rooms"). ​ Anton van Leeuwenhoek ○​ Known as the Father of Microscopy. ○​ First to observe living cells and single-celled organisms ("animalcules," later identified as bacteria). ​ Robert Brown (1831) ○​ Discovered the nucleus while studying plant cells. ○​ Observed pollen grains moving in and out of the nucleus. ​ Mathias Schleiden (1838) ○​ Proposed that cells are the basic unit of life in plants. ○​ Extensively studied plant cells under the microscope. ​ Theodor Schwann (1839) ○​ Extended Schleiden's hypothesis to animals, stating animal tissues are composed of cells. ​ Rudolf Virchow (1839) ○​ Opposed spontaneous generation and established that all cells arise from pre-existing cells ("Omnis cellula e cellula"). ○​ Studied cell division and its role in disease. The Six Tenets of Cell Theory 1.​ Cells are the basic unit of life.​ The smallest structures capable of sustaining life. 2.​ All living things are made of cells.​ From bacteria to humans, all life consists of cells. 3.​ All cells come from pre-existing cells.​ Cells reproduce through division (e.g., mitosis). 4.​ DNA is passed during cell division.​ Explains heredity and genetic similarities among organisms.  5.​ Cells of similar species share fundamental similarities.​ Organisms in the same species have consistent cellular structures and functions. 6.​ Energy flow occurs within cells.​ Cellular metabolism, like photosynthesis, is crucial for life. Here are the key points highlighted from the text: Domains of Life ​ Three domains of life: Bacteria, Archaea, and Eukarya. ​ Bacteria and Archaea are prokaryotes (single-celled, no nucleus). ​ Eukarya includes eukaryotes, which are multicellular and contain a nucleus (e.g., yeasts, algae). Prokaryotes ​ Prokaryotes lack a nucleus and membrane-bound organelles. ​ Important structures: 1.​ Pili: Hair-like structures for movement and attachment to surfaces. 2.​ Plasmid: Circular DNA molecule, distinct from chromosomal DNA. 3.​ Ribosomes: Synthesize proteins. 4.​ Cytoplasm: Jelly-like substance for cellular activities. 5.​ Cell membrane: Selectively permeable, controls substance movement. 6.​ Cell wall: Rigid layer for structure and protection. 7.​ Capsule: Helps bacteria retain moisture and protects against drying. Eukaryotes ​ Eukaryotes have a nucleus and membrane-bound organelles. ​ Key organelles: 1.​ Nucleus: Contains genetic material, regulates cell functions. ​ Nuclear envelope, nucleolus, chromatin, nucleoplasm. 2.​ Endoplasmic Reticulum (ER): Transports materials. ​ Rough ER (with ribosomes, synthesizes proteins) and Smooth ER (synthesizes fats, detoxifies). 3.​ Golgi Apparatus: Packages and transports substances. 4.​ Mitochondria: Generate energy (ATP) for biochemical reactions. 5.​ Vacuoles: Store water and chemicals. 6.​ Lysosomes: Contain enzymes for digestion. 7.​ Centrioles: Important in cell division, produce spindle fibers. Specialized Structures ​ Animal Cells: 1.​ Cytoskeleton: Maintains cell shape and facilitates movement (e.g., cilia and flagella for movement). 2.​ Centrioles: Help organize microtubules for cell division. ​ Plant Cells: 1.​ Cell Wall: Provides structure and protection. 2.​ Chloroplasts: Contain chlorophyll for photosynthesis. 3.​ Central Vacuole: Stores substances like sugars, salts, and amino acids. These are the core details of the text, focusing on cell structures, functions, and the differences between prokaryotic and eukaryotic organisms.