Untitled Flashcards Set

Detailed Study Guide for Midterm

Lab Safety

• 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.

Scientific Method

• Steps:

  1. Observation: Gather information about a phenomenon or event.

  2. Question: Ask a question based on your observations.

  3. Hypothesis: Formulate a testable hypothesis that explains your observations.

  4. Experiment: Design and conduct an experiment to test the hypothesis, varying one factor at a time while keeping others constant.

  5. Analysis: Analyze the data collected to ascertain if it supports or refutes the hypothesis.

  6. 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.

Microscopes

• 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.

Cells

• 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).

Chemical Aspects

• 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.

Macromolecules

• 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.

Cell Membrane

• 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.

Enzymes

• 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.