BIO319-FINAL-SPRING2025-ASWELL

Gene Expression Regulation

Mechanisms controlling gene activity in cells.

Transformation

Uptake of foreign DNA by a cell.

Transduction

Gene transfer via bacteriophages.

Conjugation

Direct transfer of DNA between bacteria.

Transposition

Movement of DNA segments within genomes.

Restriction Enzymes

Proteins that cut DNA at specific sequences.

Gel Electrophoresis

Technique for separating DNA fragments by size.

Recombinant DNA

DNA formed by combining DNA from different sources.

Polymerase Chain Reaction (PCR)

Method for amplifying specific DNA sequences.

Bacterial Genome

Unique DNA sequence defining a bacterial species.

DNA Replication

Process of copying DNA before cell division.

Initiation Phase

Unwinding DNA and loading polymerase enzyme.

Elongation Phase

Adding nucleotides to growing DNA strand.

Termination Phase

Completion of DNA replication process.

Point Mutation

Change of a single nucleotide in DNA.

Silent Mutation

Mutation with no effect on protein function.

Missense Mutation

Mutation resulting in a different amino acid.

Nonsense Mutation

Mutation creating a premature stop codon.

Insertion Mutation

Addition of one or more nucleotides in DNA.

Deletion Mutation

Removal of one or more nucleotides in DNA.

Frameshift Mutation

Mutation altering the reading frame of DNA.

Inversion Mutation

DNA segment flipped in orientation.

DNA Repair Mechanisms

Processes correcting DNA damage and mutations.

Base Excision Repair

Repair removing damaged DNA bases.

Methyl Mismatch Repair

Repair recognizing methylation patterns in DNA.

SOS Repair

Cellular response introducing mutations to survive.

Gene Regulation Levels

Different methods controlling gene expression.

Translational control

Regulation of transcription initiation by repressor proteins.

Post-translational control

Modification of already synthesized proteins.

Operon

A cluster of genes under single regulatory control.

Repression

Inhibition of gene expression by repressor proteins.

Induction

Activation of gene expression in response to stimuli.

Intracellular sensing

Regulatory proteins detect internal compound concentrations.

Global regulators

Proteins influencing multiple gene expressions simultaneously.

cAMP receptor protein (CRP)

Global regulator in E. coli for gene expression.

Extracellular sensing

Mechanism for bacteria to detect external conditions.

Two-component system

Phosphorylation relay for environmental signal transduction.

Sensor kinase PhoQ

Detects magnesium and pH outside Salmonella.

Genetic recombination

Exchange of genes between DNA molecules.

Vertical gene transfer

Gene transfer during reproduction across generations.

Horizontal gene transfer

Gene transfer between cells of the same generation.

Crossing over

Chromosomes break and rejoin during recombination.

Transformation

Uptake of free DNA from the environment.

Natural transformation

Inherent ability of bacteria to uptake DNA.

Artificial competence

Induced ability of bacteria to uptake DNA.

Electroporation

Electrical pulse facilitates DNA entry into cells.

Transduction

Gene transfer via bacteriophage vectors.

Bacteriophage

Virus that infects bacteria, transferring genetic material.

Specialized transduction

Transfer of specific bacterial genes by a phage.

Transposable elements

Genes that move between chromosomes, also called transposons.

Transposase gene

Enzyme that facilitates movement of transposable elements.

Plasmids

Circular, extrachromosomal DNA that replicates independently.

Resistance plasmids

Carry genes for antimicrobial resistance.

Virulence plasmids

Cause disease symptoms in hosts.

Tumor inducing plasmids

Induce tumor formation in plants.

Bacteriocinogen plasmid

Synthesize bacteriocins that kill other bacteria.

Transgenic

Organisms containing DNA from different species.

Conjugation

Gene transfer requiring contact between cells.

Hfr cells

High-frequency recombination cells in conjugation.

Genetic variation

Diversity in genetic makeup among organisms.

Plasmids

Self-replicating DNA molecules in cells.

Restriction endonuclease

Enzyme cutting DNA at specific sequences.

Palindrome sequence

DNA sequence reading the same forwards and backwards.

Gene fusion

Joining of two genes into one functional unit.

Transposition

Movement of genes within a chromosome.

Sterilization

Destruction of all living cells and viruses.

Disinfection

Killing disease-causing organisms on surfaces.

Antisepsis

Removing pathogens from living tissue surfaces.

Sanitation

Reducing microbial population to safe levels.

Cidal agents

Substances that kill microbes.

Static agents

Substances that inhibit microbial growth.

Bactericidal

Agents specifically killing bacteria.

Virucidal

Agents specifically killing viruses.

Bacteriostatic

Agents inhibiting bacterial growth.

Antimicrobial spectrum

Range of microorganisms affected by agents.

Biosafety Levels

Ranking of disease severity and transmission ease.

Selection of disinfectant

Criteria for choosing effective disinfectants.

Microbial load

Amount of microorganisms present on a surface.

Microbial Death Curve

Graph showing microbial death rates over time.

Initial Population Size

Larger populations take longer to reduce.

Population Composition

Presence of spores affects microbial resistance.

Agent Concentration

Higher doses increase effectiveness of microbial control.

Duration of Exposure

Longer exposure enhances lethal damage accumulation.

Organic Material Presence

Organic load inhibits disinfectant action effectiveness.

Physical Control Measures

Methods to control microbes without chemicals.

Temperature Extremes

High or low temperatures kill or inhibit microbes.

Pressure

Combined with heat to enhance microbial control.

Filtration

Removes microbes from liquids using micropore filters.

Irradiation

Uses high-energy radiation to kill microorganisms.

Moist Heat

Effective method for killing microbes and spores.

Dry Heat

Less effective than moist heat for sterilization.

Steam Autoclave

Uses heat and pressure to kill thermophiles.

Standard Autoclave Conditions

121°C at 15 psi for 20 minutes.

Thermal Death Point (TDP)

Temperature killing all bacteria in 10 minutes.

Thermal Death Time (TDT)

Time to kill all bacteria at specific temperature.

Decimal Reduction Time (D value)

Time to kill 90% of organisms at specific temperature.

Pasteurization

Kills pathogens without affecting product quality.

Low Temperature, Long Time (LTLT)

Pasteurization method using low heat over extended time.

High Temperature, Short Time (HTST)

Pasteurization method using high heat for short time.

Ultra High Temperature (UHT)

Pasteurization method for shelf-stable products.