Microbiology Finals Study Guide

Vocabulary flashcards based on lecture notes for microbiology final exam.

Spontaneous Generation

The hypothesis that living organisms can arise from non-living matter; widely accepted until the 19th century.

Biogenesis

The theory that living organisms arise from other living organisms, not spontaneously from non-living material.

Redi's Meat Experiment

Demonstrated that maggots on meat came from flies, disproving spontaneous generation.

Pasteur's Swan Flask Experiment

Showed that microbes in the air were the source of contamination, not spontaneous generation.

Robert Hooke's Microscopic Observations

Observed cork under a microscope and coined the term 'cells'.

Anton van Leeuwenhoek's Observations

Discovered 'animalcules' (microorganisms) in pond water.

Germ Theory of Disease

Diseases are caused by microorganisms, not spontaneous factors.

Joseph Lister's Antiseptic Surgery

Used carbolic acid to disinfect surgical instruments and wounds.

Robert Koch's Experiments

Identified Bacillus anthracis as the cause of anthrax, establishing Koch's postulates.

Bacteria

Unicellular, prokaryotic microorganisms.

Yeast

Unicellular or multicellular, eukaryotic microorganisms.

Viruses

Non-cellular, non-living infectious agents.

Three Domains of Life

Bacteria, Archaea, and Eukarya.

Bacteria Domain

Prokaryotic organisms with peptidoglycan in their cell walls.

Archaea Domain

Prokaryotic organisms without peptidoglycan in their cell walls, some contain introns.

Eukarya Domain

Eukaryotic organisms with introns and a membrane-bound nucleus.

Genus and Species Format

Italicized with the genus capitalized and the species in lowercase (e.g., Escherichia coli).

16S rRNA

A highly conserved gene sequence used to classify organisms into domains.

Taxonomy

The science of classification, involving naming, describing, and organizing organisms.

Phylogeny

The evolutionary history and relationships among organisms.

Serology

Study of antigen-antibody interactions.

MALDI-TOF

A mass spectrometry technique to identify organisms based on their protein fingerprints.

FISH (Fluorescence In Situ Hybridization)

Used to visualize specific nucleic acids in cells.

NAATS/PCR

Techniques for amplifying and detecting specific DNA sequences.

DNA-DNA Hybridization

Measures relatedness by determining how much two DNA strands from different organisms bind together.

Species vs. Strains

A species is a group with high genetic similarity, while strains represent subgroups with unique traits.

Capsule/Slime Layer

A protective outer layer that protects the cell from phagocytosis and desiccation.

Cell Wall (Prokaryotic)

Provides structure and protection; composed of peptidoglycan.

Plasma Membrane

Regulates transport and provides structural integrity.

Ribosomes

Sites of protein synthesis.

Pili

Appendages for attachment (e.g., F-pili for conjugation).

Endospores

Resistant structures for survival in harsh conditions.

Plasmids

Small, circular DNA molecules carrying extra genes.

Gram-Positive Cells

Cells with a thick peptidoglycan wall.

Gram-Negative Cells

Cells with a thin peptidoglycan wall and an outer membrane.

Ocular Lens

The eyepiece of a microscope.

Objective Lenses

The primary lenses on a microscope that magnify the sample.

Stage

The platform of a microscope where the sample is placed.

Diaphragm

Controls the amount of light reaching the sample in a microscope.

Light Source

Provides illumination for viewing the sample under a microscope.

TEM (Transmission Electron Microscope)

An electron microscope where a beam of electrons is transmitted through a specimen to form an image.

SEM (Scanning Electron Microscope)

An electron microscope that scans a focused electron beam over a surface to create an image.

Acidic Dyes

Dyes with a negative charge, which stain positively charged structures.

Basic Dyes

Dyes with a positive charge, which stain negatively charged structures.

Simple Stain

A staining technique using a single dye to provide contrast.

Differential Stain

A staining technique using multiple dyes to distinguish between different types of cells or structures (e.g., Gram stain).

Gram Stain

Involves crystal violet, iodine, alcohol, and safranin to distinguish Gram-positive from Gram-negative bacteria.

Heat Fixation

Used to adhere the sample to the slide and kill the cells.

Binary Fission

Prokaryotic cell division where one cell divides into two.

Exponential Growth

A pattern of growth where the population doubles at regular intervals.

Biofilms

Complex communities of microorganisms adhering to surfaces.

Lag Phase

Cells adapt to new conditions.

Log/Exponential Phase

Rapid cell division; most sensitive to antibiotics.

Stationary Phase

Rate of cell division equals the rate of cell death.

Death Phase

Cell death rate exceeds cell division; logarithmic decrease in cell number.

Phase of Prolonged Decline

A few survivors continue to divide, often due to adaptations.

Psychrophiles

Thrive at low temperatures (e.g., arctic environments).

Mesophiles

Optimal growth at moderate temperatures (e.g., human body).

Thermophiles

Prefer higher temperatures (e.g., hot springs).

Psychotrophs

Grow at low temperatures but can also thrive at moderate temperatures.

Hyperthermophiles

Thrive at extreme temperatures (e.g., hydrothermal vents).

Obligate Aerobes

Require oxygen for growth.

Microaerophiles

Grow best in low oxygen conditions.

Obligate Anaerobes

Cannot tolerate oxygen.

Aerotolerant Anaerobes

Tolerate oxygen but don't use it.

Facultative Anaerobes

Can grow with or without oxygen.

Photoautotrophs

Use light energy and carbon dioxide for growth.

Photoheterotrophs

Use light energy but require organic carbon.

Chemolithoautotrophs

Use inorganic chemicals for energy and carbon dioxide for carbon.

Chemoorganoheterotrophs

Use organic chemicals for both energy and carbon.

Sterilization

Destruction of all microbial life, including spores and viruses.

Pasteurization

Application of mild heat to destroy pathogens and reduce spoilage organisms.

Sanitization

Reduction of microbial levels to a safe level.

Antisepsis

Application of chemicals to living tissue to destroy/inhibit microbes.

Disinfection

Use of chemicals to kill/inhibit microbes on inanimate objects.

Preservation

Methods to slow or prevent microbial growth in foods/biological samples.

HEPA Filters

High-Efficiency Particulate Air filters, used to remove airborne microbes.

Decimal Reduction Time (D-value)

The time required to reduce a microbial population by 90% at a specific temperature or condition.

Critical Items

Items that enter sterile tissues or blood; require sterilization.

Semicritical Items

Items that contact mucous membranes but do not penetrate tissues; require high-level disinfection.

Non-Critical Items

Items that contact intact skin; require sanitization or low-level disinfection.

Moist Heat

Methods include boiling, pasteurization and using an autoclave.

Dry Heat

Methods include hot air ovens and incineration.

Ionizing Radiation

X-rays, Gamma Rays.

UV Light

Causes DNA mutations, used for disinfecting surfaces, air, and water.

Low-Level Germicides

Kill vegetative bacteria, fungi, and enveloped viruses; used for non-critical items.

Intermediate-Level Germicides

Kill vegetative bacteria, fungi, mycobacteria, and most viruses; used for semicritical items.

High-Level Germicides

Kill all vegetative organisms and most spores; used for semicritical and critical items.

Bacterial Endospores

Highly resistant to heat and chemicals; require autoclaving or high-level disinfectants.

Protozoan Cysts

Resistant to disinfection; require higher-level disinfectants or boiling.

Enveloped Viruses

Generally less resistant due to the presence of a lipid envelope.

Selective Toxicity

Ability of an antibiotic to target microbes without harming host cells.

Bacteriostatic

Antibiotics that inhibit bacterial growth without killing them.

Bactericidal

Antibiotics that kill bacteria.

Broad-Spectrum Antibiotics

Effective against a wide range of microbes.

Narrow-Spectrum Antibiotics

Effective against a specific group of microbes.

Antibiotic Resistance

Bacteria develop resistance mechanisms, reducing drug efficacy.

Half-Life (Antibiotic)

The time required for the concentration of an antibiotic in the body to be reduced by half.

Beta-Lactams

Antibiotics (penicillins, cephalosporins) that interfere with peptidoglycan formation.

Glycopeptides

Antibiotics (vancomycin) that bind to cell wall precursors, preventing peptidoglycan formation.