Comprehensive Laboratory & Biochemical Analysis Study Guide

Vocabulary flashcards covering review topics for the Week 3 lab quiz including the scientific method, biochemical testing, safety protocols, and metric measurement conversions.

Scientific Method

A structured, step-by-step process of scientific investigation that includes making observations, formulating hypotheses, conducting experiments, analyzing data, and drawing conclusions.

Hypothesis

A proposed, testable, and falsifiable explanation created to answer a specific scientific question or observation.

Null Hypothesis

A statistical statement proposing that there is no significant difference, effect, or relationship between experimental groups or variables.

Independent Variable

The specific factor or condition in an experiment that is intentionally manipulated or changed by the experimenter.

Dependent Variable

The factor measured or observed in an experiment, which changes in response to manipulations of the independent variable.

Positive Control

An experimental control group designed to yield a known positive result, verifying that the testing reagents and procedures are functioning properly.

Negative Control

An experimental control group designed to yield a negative result or no change, verifying that non-specific reactions or contamination are absent.

Standard Deviation

A statistical calculation used to quantify the amount of variation, spread, or precision of a dataset relative to its mean.

Biuret Reagent

A biochemical reagent containing copper ions used to test for proteins by reacting with peptide bonds to produce a violet or purple color.

Purpose of $\text{NaOH}$ in Biuret Test

Provides an alkaline environment necessary for copper ions in the Biuret reagent to form a complex with peptide bonds.

Monosaccharides

The single-sugar monomers that serve as the basic structural building blocks for complex carbohydrates.

Reducing Sugar

A sugar containing a free aldehyde or ketone group capable of donating electrons and reducing chemical reagents such as Benedict's reagent.

Benedict's Test

A biochemical assay used to detect reducing sugars that requires heating samples to produce a color change ranging from green to reddish-brown.

Starch

A complex polysaccharide carbohydrate composed of glucose monomers that serves as energy storage in plant cells.

Lipids

Hydrophobic, nonpolar biological molecules composed primarily of glycerol and fatty acid subcomponents.

Sudan IV

A fat-soluble dye used to test for lipids by selectively staining nonpolar, hydrophobic substances reddish-orange.

MSDS

Material Safety Data Sheet; an essential reference document detailing chemical health hazards, physical safety properties, handling guidelines, and emergency first-aid protocols.

Flame Symbol

A standardized laboratory hazard pictogram indicating that a chemical substance is flammable or pyrophoric.

PPE

Personal Protective Equipment, including safety goggles, lab coats, and gloves, worn to protect individuals from laboratory hazards.

NFPA Diamond

A colored four-quadrant diamond system used to visually communicate health, flammability, instability, and specific chemical hazards.

Fume Hood

A ventilated laboratory containment enclosure designed to draw away and safely exhaust dangerous chemical fumes, vapors, or dusts.

HCS Labels

Hazard Communication Standard labels required on chemical containers to provide essential safety hazard warnings and protective information.

Meniscus

The curved upper surface of a liquid column in a graduated container, which must be read at eye level at its lowest point.

$$\mu\text{L}$$

Microliter, a metric unit of volume equal to $10^{-6}\,\text{L}$ or one-millionth of a liter.

Kilo-

A metric prefix representing a factor of $10^3$ or $1000$ units.

Unit Conversion from Larger to Smaller

The process of converting a metric measurement to a smaller unit by moving the decimal point to the right.

$0.0007\,\text{g}$ in $\mu\text{g}$

Equal to $700\,\mu\text{g}$, calculated by multiplying $0.0007\,\text{g}$ by $10^6\,\mu\text{g}/\text{g}$.

Precision

The degree of mutual agreement, closeness, or repeatability among independent measurements of the same quantity.

First Aid for Corrosive Liquid Exposure

Immediately rinse affected hands or skin with continuous running water to dilute and remove the corrosive chemical.

First Aid for Chemical Eye Exposure

Immediately flush the eyes at an emergency eyewash station for a minimum of 15 to 20 minutes.

Chemical Waste Disposal Protocol

The safety protocol requiring chemical residues and hazardous waste to be collected in designated waste containers rather than poured into standard sinks.