CMM111 Midterm Edition (AI generated)

P1000 pipette

Dispenses 100-1000 µl.

P20 pipette

Dispenses 2-20 µl.

Forward pipetting

Aqueous solutions

Reverse pipetting

Viscous liquids

Repetitive pipetting

For dispensing the same volume multiple times.

Beer Lambert's Law

A = εcl (Absorbance = molar absorptivity × concentration × path length).

Spectrophotometer

Measures absorbance of light in a solution.

Resolution formula

d = λ / 2NA (d = resolution

Microscope magnification

Total magnification = Eyepiece mag × Objective mag.

Stage micrometer

Used to calibrate the eyepiece graticule.

Eyepiece graticule

Measures sample size under the microscope.

Oil immersion

Used with the 100X lens to improve resolution.

Serial dilution

Dilutes a substance multiple times by a factor (e.g.

Dilution formula

C1V1 = C2V2 (Initial conc. × Initial vol. = Final conc. × Final vol.).

T-test

Statistical test comparing means of two groups.

Paired sample T-test

Compares means from the same group over time.

Independent sample T-test

Compares means between two different groups.

Allura Red

Common food dye used in absorbance measurement.

Mitosis

Process of cell division producing two identical cells.

Interphase

Preparation phase before mitosis (G1

Prophase

Chromosomes condense

Metaphase

Chromosomes align in the center of the cell.

Anaphase

Sister chromatids are pulled to opposite ends of the cell.

Telophase

Nuclear membranes reform

Cytokinesis

Division of the cytoplasm

Mitotic index

Percentage of cells undergoing mitosis = (Mitosis cells / Total cells) × 100.

Apoptosis

Programmed cell death

Necrosis

Unintentional cell death due to damage or injury.

Autophagy

Cellular degradation of organelles using lysosomes.

Cancer

Uncontrolled cell growth

Chemotherapy

Treatment targeting rapidly dividing cancer cells.

5-Fluorouracil (5FU)

Chemotherapy drug inhibiting DNA synthesis.

MTT assay

Measures cell viability by assessing metabolic activity.

DNA fragmentation

A key indicator of apoptosis in cells.

Absorbance formula

A = -log(T) (A = absorbance

Spectrophotometer blank

Solution used to zero the spectrophotometer.

Cuvette

A small

Path length

Distance light travels through the sample in the cuvette (typically 1 cm).

Absorbance maximum

Wavelength where a substance absorbs the most light.

Catalase

Enzyme that breaks down hydrogen peroxide into water and oxygen.

H2O2 decomposition

2H2O2 → 2H2O + O2 (Breakdown of hydrogen peroxide).

CTT1 gene

Gene encoding catalase T in yeast cells.

Protein concentration assay

Uses Bradford reagent to measure protein.

Bradford reagent

Reagent that binds proteins and changes color for absorbance measurement.

Yeast cells

Used in lab experiments to study enzyme activity and genetics.

Wild-type yeast

Normal yeast strain used as a control in experiments.

Dctt1 mutant yeast

Yeast strain lacking catalase T for H2O2 breakdown.

Centrifugation

Spins samples at high speed to separate components.

Vortexing

Mixing technique used to thoroughly combine samples.

Glass beads

Used in cell disruption to break open yeast cells for analysis.

Cell viability formula

Viability = (A_treated / A_control) × 100 (MTT assay result calculation).

Oxidative stress

Damage caused by reactive oxygen species like hydrogen peroxide.

Peroxisomes

Organelles in cells that contain catalase to detoxify H2O2.

Hydrogen peroxide (H2O2)

Reactive oxygen species broken down by catalase.

Optical density (OD)

Measurement of how much light is absorbed by a sample.

Standard curve

Graph of known concentrations to calculate unknown values.

Incident light

Light that strikes a sample in a spectrophotometer.

Transmitted light

Light that passes through the sample in a spectrophotometer.

Spectrophotometer wavelength range

Typically measures light between 190-900 nm.

Cell death types

Apoptosis (programmed)

Cell plate

Structure that forms between two dividing plant cells during cytokinesis.

Cleavage furrow

Indentation in an animal cell where the cell begins to divide during cytokinesis.

Contractile ring

Structure made of actin that helps form the cleavage furrow in animal cells.

Chromatin

Uncondensed form of DNA found during interphase.

Spindle fibers

Protein structures that pull chromosomes apart during mitosis.

Centrosomes

Organelles that organize spindle fibers during mitosis.

Kinetochore

Structure on chromatids where spindle fibers attach during mitosis.

Metaphase plate

Imaginary plane where chromosomes align during metaphase.

Contractile proteins

Involved in the formation of the cleavage furrow in cytokinesis.

Golgi apparatus

Organelle involved in producing the cell plate in plant cytokinesis.

Spectrophotometer calibration

Process of setting the machine to zero using a blank solution.

Graphing absorbance

Plot absorbance against concentration to create a standard curve.

Microscope light source

Provides illumination for observing specimens.

Numerical aperture

Lens's ability to gather light

Microscope fine focus

Used to adjust the focus precisely when viewing a specimen.

Microscope coarse focus

Moves the stage up or down to bring the sample into view.

Objective lens

Provides varying levels of magnification (e.g.

Iris diaphragm

Adjusts the amount of light reaching the specimen on the microscope.

Condenser

Focuses light on the sample to improve image clarity in microscopy.

Lab 1 procedure

Measure Allura Red concentration in drinks using absorbance.

Lab 1 analysis

Create a standard curve from known Allura Red concentrations.

Lab 2 procedure

Prepare onion skin samples and visualize under the microscope.

Lab 2 observations

Identify cell organelles and microorganisms from pond water.

Lab 3 procedure

Prepare onion root tips to observe stages of mitosis.

Lab 3 observation

Calculate mitotic index from observed cells.

Lab 4 procedure

Investigate cell death and DNA fragmentation using staining techniques.

Lab 4 analysis

Identify apoptosis through DNA fragmentation patterns.

Lab 5 procedure

Measure catalase activity in yeast strains with H2O2 exposure.

Lab 5 results

Compare catalase activity between wild-type and mutant yeast.