General Biology Lab Study Guide: Safety, Scientific Method, Microscopy, Macromolecules, Diffusion, and Core Biochemical Processes

스터디 가이드 - 스마트 노트

자료에 맞춘 맞춤형 노트, 핵심 정의, 예시, 맥락을 확장해 제공합니다.

Lab Safety

Personal Protective Equipment (PPE)

Personal Protective Equipment (PPE) refers to specialized clothing or equipment worn for protection against laboratory hazards.

Examples of PPE: Lab coats, gloves, safety goggles, face shields.
Purpose: To minimize exposure to chemicals, biological agents, and physical hazards.

Scientific Method

Steps of the Modern Scientific Method

The scientific method is a systematic approach to inquiry used in biology and other sciences.

Observation: Gathering information about a phenomenon.
Question: Formulating a question based on observations.
Hypothesis: Proposing a testable explanation.
Experiment: Designing and conducting tests to evaluate the hypothesis.
Data Collection: Gathering and recording results.
Analysis: Interpreting data to draw conclusions.
Conclusion: Accepting, rejecting, or modifying the hypothesis.
Communication: Sharing results with the scientific community.

Key Terms

Independent Variable: The factor that is changed or manipulated in an experiment.
Dependent Variable: The factor that is measured or observed in response to changes in the independent variable.
Controlled Variables: Factors kept constant to ensure a fair test.
Hypothesis: A testable statement predicting the outcome of an experiment.
Theory: A well-substantiated explanation of some aspect of the natural world, based on a body of evidence.
Qualitative Data: Descriptive data (e.g., color, texture).
Quantitative Data: Numerical data (e.g., measurements, counts).

Microscope

Parts and Functions of the Compound Light Microscope

Ocular Lens (Eyepiece): Magnifies the image, usually 10x.
Objective Lenses: Provide additional magnification (commonly 4x, 10x, 40x, 100x).
Stage: Platform where the slide is placed.
Stage Clips: Hold the slide in place.
Coarse/Fine Focus Knobs: Adjust the focus of the image.
Light Source: Illuminates the specimen.
Condenser: Focuses light onto the specimen.
Diaphragm: Regulates the amount of light.

Resolution and Magnification

Resolution: The ability to distinguish two close points as separate; higher resolution means clearer detail.
Magnification: The process of enlarging the appearance of an object.
Total Magnification: Calculated as:

Identifying Cell Organelles

Plant Cells: Cell wall, chloroplasts, central vacuole, nucleus.
Animal Cells: Nucleus, mitochondria, plasma membrane, lysosomes.

Metric System

Metric Conversions

The metric system is based on powers of ten. Common units include meter (m), liter (L), and gram (g).

Prefixes: kilo- (103), centi- (10-2), milli- (10-3), micro- (10-6).
Conversion Example: To convert 5 cm to mm:

Macromolecules

Classes and Monomers

Carbohydrates: Monomer = monosaccharide (e.g., glucose)
Proteins: Monomer = amino acid
Lipids: Monomer = fatty acids and glycerol
Nucleic Acids: Monomer = nucleotide

Testing for Macromolecules

Macromolecule	Test	Color Change
Reducing Sugar	Benedict's Test	Blue to orange/red
Starch	Iodine Test	Brown/yellow to blue-black
Protein	Biuret Test	Blue to violet
Lipid	Sudan III/IV or Grease Spot Test	Red-stained oil droplets/grease spot

Protein Estimation: Bradford Method

Principle: Coomassie Brilliant Blue dye binds to proteins, causing a color change from brown to blue.
Graphing: Absorbance is plotted against known protein concentrations to create a standard curve. Unknown concentrations are determined from this curve.

Diffusion and Osmosis

Definitions

Diffusion: The movement of molecules from an area of higher concentration to lower concentration.
Osmosis: The diffusion of water across a selectively permeable membrane.

Factors Affecting Diffusion Rate

Concentration gradient
Temperature
Molecule size
Membrane permeability

Dialysis Tubing Experiment

Starch: Too large to pass through tubing.
Iodine: Small enough to diffuse into tubing.
Glucose: Small enough to diffuse out of tubing.

Cell Behavior in Solutions

Solution Type	Animal Cell Response	Plant Cell Response
Isotonic	No net water movement; cell remains normal	No net water movement; cell is flaccid
Hypotonic	Water enters; cell may burst (lysis)	Water enters; cell becomes turgid (firm)
Hypertonic	Water leaves; cell shrinks (crenation)	Water leaves; cell undergoes plasmolysis

Enzymes, Cellular Respiration, and Photosynthesis

Substrates and Products

Enzyme Reactions: Substrate binds to enzyme, converted to product.
Cellular Respiration: Substrate = glucose + O2; Products = CO2 + H2O + ATP
Photosynthesis: Substrate = CO2 + H2O; Products = glucose + O2

Experimental Design

Control Sample: The sample that does not receive the experimental treatment; used for comparison.
Independent Variable: The factor changed by the experimenter (e.g., temperature, pH).
Dependent Variable: The measured outcome (e.g., rate of reaction, amount of product).

Conclusions and Factors Affecting Enzyme Function

Conclusions: Drawn by comparing experimental and control results.
Factors Affecting Enzyme Activity: Temperature, pH, substrate concentration, enzyme concentration, presence of inhibitors or activators.

Chromatography and Rf Value

Chromatography: Technique for separating mixtures based on movement through a medium.
Rf Value Calculation:

Bromothymol Blue

Indicator: Used to detect pH changes.
Color in Acidic Conditions: Yellow
Color in Basic Conditions: Blue

Respiration and Carbon Dioxide Production

Rate of Respiration: Higher rates produce more CO2.
CO2 Detection: Can be measured by pH indicators or gas collection.