midterm Ultimate Study Guide

Independent Variable (IV)

The factor systematically manipulated by the investigator to observe its effects, plotted on the horizontal axis (x-axis) in graphs.

Dependent Variable (DV)

The measurable outcome that changes in response to the independent variable, plotted on the vertical axis (y-axis) in graphs.

Controlled Variables (Constants)

Environmental factors kept identical across experimental setups to prevent confounding variables.

Control Group

The baseline group that does not receive the experimental treatment, used for comparison.

Replication

Execution of an experiment across multiple trials to minimize random error and establish reliability.

Hypothesis

A testable statement proposing a specific relationship between the independent and dependent variables.

Dehydration Synthesis

The biochemical mechanism by which monomers bond covalently, releasing a water molecule as a byproduct.

Hydrolysis

The chemical reaction that cleaves polymers into monomers through the addition of water.

Benedict's Assay

A test for reducing sugars, where positive results yield colors from green to brick red; requires high heat.

Iodine (Lugol's) Assay

A test for starch, producing a dark blue/black color in a positive result; conducted at room temperature.

Biuret Assay

A test for proteins that yields a violet color in a positive result, requiring at least four peptide bonds.

Ocular Lens (Eyepiece)

The lens through which the viewer observes the specimen, providing a magnification of 10x.

Objective Lenses

Magnification lenses mounted on a revolving nosepiece, providing different levels of magnification.

Total Magnification

The product of ocular lens magnification and objective lens magnification.

Brownian Motion

The random movement of microscopic molecules in a fluid medium driven by thermal energy.

Concentration Gradient

The difference in solute concentration between two regions or across a membrane.

Hypotonic Solutions

Solutions with a lower solute concentration outside the cell, resulting in water influx and possible cell lysis.

Hypertonic Solutions

Solutions with a higher solute concentration outside the cell, resulting in water efflux and cell crenation.

Isotonic Solutions

Solutions with equal solute concentration inside and outside the cell, resulting in no net change in cell volume.

Dialysis Tubing

A semi-permeable membrane used in experiments to model selective permeability based on size.

Glucose

A small, low-molecular-weight monosaccharide that can diffuse through dialysis tubing.

Starch

A large polysaccharide that cannot diffuse through dialysis tubing, demonstrating selective permeability.