Finals Lab Study Guide

What is the metric system?

A standardized measurement system based on units of 10 (meters, liters, grams).

How do you convert metric units (length, weight, volume)?

: Move the decimal point by powers of 10 (e.g., kilo → base → milli).

What are micropipette size ranges used for?

• 2–20 µL: very small volumes

• 10–100 µL: small volumes

• 100–1000 µL: larger volumes

How do you use a micropipette?

First stop = draw liquid; second stop = fully release liquid

What is accuracy?

How close a measurement is to the true value.

What is precision?

How close repeated measurements are to each other.

What does absorbance measure?

The amount of light absorbed by a sample.

Relationship between concentration, absorbance, and transmittance?

↑ concentration → ↑ absorbance → ↓ transmittance.

What is a best fit line?

A line that best represents data trends on a graph.

Relationship between temperature and density?

As temperature increases, density generally decreases.

What is percent error?

Percent error=Iexperimental-trueI/true times 100

 Difference between qualitative and quantitative analysis?

• Qualitative: presence of substance

• Quantitative: how much of substance

What is the Biuret test?

Detects proteins via copper binding to peptide bonds → purple color.

Biuret test results?

• Purple = protein present

• Blue = no protein

What is BSA?

Bovine serum albumin, a standard protein used in experiments.

What does low BSA indicate?

Possible liver disease.

What is a serial dilution?

Stepwise dilution to reduce concentration.

What is the dilution formula?

C1V1=C2V2

What is an independent variable?

The factor you change (cause).

What is a dependent variable?

The measured outcome (effect).

Factors affecting enzyme activity?

Substrate concentration, enzyme concentration, pH, inhibitors, temperature.

What is optimum temperature?

The temperature where enzyme activity is highest.

What does the base do?

Contains the light source.

What does the condenser do?

Focuses light on the specimen.

What does the stage do?

Holds the slide.

Objective lens magnifications?

4x, 10x, 40x, 100x (oil immersion).

Ocular lens magnification?

10x.

Magnification vs resolution?

• Magnification = size increase

• Resolution = clarity/detail

Main difference between plant and animal cells?

Plant cells have cell walls and chloroplasts; animal cells do not.

What is a zwitterion?

A molecule with both positive and negative charges.

What does protonated mean?

Gains H⁺ → more positive charge.

What does deprotonated mean?

Loses H⁺ → more negative charge.

What is the isoelectric point?

pH where net charge = 0.

What is electrophoresis?

Separation based on charge using an electric field.

What is chromatography?

Separation based on movement through a medium.

What is complete oxidation?

Breakdown of glucose into CO₂ and H₂O.

What is photosynthesis?

Produces glucose from CO₂ and H₂O.

What is cellular respiration?

Breaks glucose into CO₂ and H₂O.

What is titration used for here?

Measuring respiration rates.

Rate of respiration formula?

Respiratory Rate (RR)= Number of Breaths/Time in Minutes

What happens in the light reaction?

Light energy → chemical energy; water splits → O₂ released.

What happens in the dark reaction?

Uses energy to make glucose from CO₂.

What is chlorophyll’s role?

Absorbs light energy.

Why do leaves change color?

Chlorophyll breaks down, revealing other pigments

What is interphase?

Growth and DNA replication (G1, S, G2).

What happens in prophase?

Chromosomes condense, spindle forms.

What happens in metaphase?

Chromosomes align.

What happens in anaphase?

Chromatids separate.

What happens in telophase?

Nuclei reform, cytokinesis occurs.

Mitosis vs meiosis?

• Mitosis: identical cells

• Meiosis: gametes, genetic variation

Meiosis I vs II?

• I: homologous chromosomes separate

• II: sister chromatids separate

What are nucleotides?

DNA building blocks (sugar, phosphate, base).

DNA vs RNA?

• DNA: double strand, thymine

• RNA: single strand, uracil

What is the central dogma?

DNA → RNA → Protein.

Base pairing rule?

A-T, C-G.

What is transcription?

DNA → RNA.

What is translation?

RNA → protein.

Why use Drosophila?

Fast reproduction, simple genetics.

What is a retrotransposon?

DNA element that moves within genome.

What pigments affect eye color?

Pteridine and ommochrome.

What is PCR?

DNA amplification technique.

PCR requirements?

DNA, primers, Taq polymerase, nucleotides, buffer.

PCR steps?

Denaturation → annealing → extension.

What is Elodea?

A aquatic plant used to observe osmosis.

Isotonic solution?

Equal solute concentration.

Hypertonic solution?

Higher solute outside → cell shrinks.

Hypotonic solution?

Lower solute outside → cell swells.

What is plasmolysis?

Cell membrane pulls away from wall.

Solute vs solvent?

• Solute = dissolved substance

• Solvent = dissolving medium

Benedict’s reagent detects?

Simple sugars

IKI detects?

Starch.

What is chromatography?

Separation based on movement through a medium.

Pigment pathways?

Pteridine and ommochrome.

Effect of mutations?

Changes eye color phenotype.