Basic Lab Safety Rules:
Personal Protective Equipment: Always wear safety goggles to protect your eyes, gloves to protect your hands, and a lab coat to protect your skin and clothing.
Awareness: Be aware of your surroundings, including the location of exits and safety equipment such as fire extinguishers, eyewash stations, and safety showers.
Food and Drink: Never eat or drink in the lab to prevent contamination.
Chemical Handling: Always read labels and follow protocols for handling chemicals; do not mix chemicals unless instructed to do so.
Cleanliness: Keep your work area clean and organized. Clean up spills immediately and dispose of waste as directed.
Steps:
Observation: Gather information about a phenomenon or event.
Question: Ask a question based on your observations.
Hypothesis: Formulate a testable hypothesis that explains your observations.
Experiment: Design and conduct an experiment to test the hypothesis, varying one factor at a time while keeping others constant.
Analysis: Analyze the data collected to ascertain if it supports or refutes the hypothesis.
Conclusion: Draw conclusions from your analysis and determine if your hypothesis was supported. Consider repeating the experiment or conducting further research.
Designing a Proper Experiment:
Define a clear and concise hypothesis.
Identify independent (manipulated), dependent (measured), and controlled variables.
Outline a comprehensive procedure with clear steps and controls.
Decide on data collection methods (qualitative vs quantitative) and statistical analysis as needed.
Using a Compound Microscope:
Setup: Ensure the microscope is correctly positioned and illuminated.
Focusing: Start with the lowest power objective (4X or 10X), use coarse focus first, and then fine focus for clarity.
Adjustments: Make sure to adjust the diaphragm for optimal light, and switch to higher magnifications only after achieving clarity at lower levels.
Handling: Always carry the microscope with two hands (one on the arm and one on the base) and ensure it’s turned off when not in use.
Know the Organelles:
Nucleus: Control center of the cell containing DNA.
Mitochondria: Powerhouse of the cell, site of ATP production.
Ribosomes: Sites of protein synthesis; can be free-floating or attached to endoplasmic reticulum.
Endoplasmic Reticulum (Rough and Smooth): Rough ER synthesizes proteins; Smooth ER synthesizes lipids and detoxifies drugs.
Golgi Apparatus: Modifies, sorts, and packages proteins and lipids for secretion.
Lysosomes: Contain digestive enzymes for waste processing.
Chloroplasts (in plant cells): Site of photosynthesis; contain chlorophyll and other pigments.
Cell Membrane: Semi-permeable membrane controlling the movement of substances into and out of the cell.
Identification Skills:
Be able to label diagrams of both plant and animal cells with accuracy.
Understand differences in structure (e.g., cell wall in plant cells).
Atomic Number and Mass:
Atomic Number: Indicates the number of protons in an atom’s nucleus. Determines the element's identity.
Mass Number: Total number of protons and neutrons in an atom. Calculate neutrons by subtracting the atomic number from the mass number.
Electrons: In a neutral atom, the number of electrons equals the number of protons.
Lewis Structures and Bohr Models:
Lewis Structures: Diagrams that show bonds between atoms and the lone pairs of electrons.
Bohr Models: Represent atom structure with electrons arranged in energy levels or shells around the nucleus.
Ionic and Covalent Bonds:
Ionic Bonds: Formed when electrons are transferred from one atom to another, leading to the formation of charged ions.
Covalent Bonds: Formed when atoms share pairs of electrons; results in strong, stable connections.
Basic vs Acidic Solutions:
pH Scale: Ranges from 0 to 14; 7 is neutral, below 7 is acidic, above 7 is basic.
Know examples, e.g., battery acid (pH 1) is extremely acidic, while bleach (pH 12) is extremely basic.
Detection Tests:
Biuret Test: Tests for proteins; a positive result turns the solution purple.
Benedict’s Test: Tests for reducing sugars; a positive result turns from blue to green/orange/red.
Iodine Test: Tests for starch; a positive result turns blue-black.
Grease Spot Test: Tests for lipids; positive result leaves a translucent spot on paper.
Concentration Gradient:
Occurs when there is a difference in concentration of a substance across a space.
Active vs Passive Transport:
Active Transport: Movement of molecules against their concentration gradient, requiring energy (e.g., Na+/K+ pump).
Passive Transport: Movement of molecules along their concentration gradient without energy (e.g., diffusion of oxygen).
Molecular Movement:
Understand how factors like temperature, size of molecules, and permeability affect diffusion rates and lab observations regarding diffusion and osmosis.
Functionality:
Enzymes are biological catalysts that lower the activation energy of reactions, thus speeding up processes.
Factors affecting enzyme activity: temperature, pH, substrate concentration, and presence of inhibitors or activators.
Lab Results:
Be able to interpret results from enzyme activity experiments, including changes in substrate or product concentration over time, and relate those findings to enzyme efficiency.