MDMI-103 Microbiology Health & Disease - Exam 1 Study Guide

Vocabulary flashcards reviewing core concepts, key scientists, basic chemistry, bacterial structures, staining techniques, microbial metabolism, growth kinetics, and control methods for MDMI-103 Lectures 1-7.

Edward Jenner

Demonstrated that exposure to cowpox provides protection against smallpox, establishing the principle of vaccination.

Antonie van Leeuwenhoek

The first scientist to make detailed observations of living microorganisms using a simple microscope.

Louis Pasteur

Demonstrated that microorganisms cause fermentation, helped disprove spontaneous generation, provided experimental support for the germ theory of disease, and developed pasteurization.

Robert Koch

Provided experimental evidence linking specific microorganisms to specific diseases and developed Koch's postulates.

Joseph Lister

Introduced antiseptic surgical techniques based on germ theory to prevent surgical wound contamination and infections.

Alexander Fleming

Discovered the antibacterial activity of penicillin, an antibiotic naturally produced by the fungus Penicillium.

Penicillium

A fungus (mold) that is the natural source of the antibacterial antibiotic penicillin.

Koch's postulates

A set of criteria traditionally used to establish whether a specific microorganism causes a specific disease.

Proton

A positively charged subatomic particle located in the nucleus of an atom.

Neutron

An uncharged (neutral) subatomic particle located in the nucleus of an atom.

Electron

A negatively charged subatomic particle located outside the nucleus of an atom.

Atomic number

The number of protons in an atom, which determines the identity of an element.

Mass number

The total number of protons plus neutrons in an atom's nucleus.

Covalent bond

A chemical bond formed when two atoms share one or more pairs of electrons.

Ionic bond

A chemical bond formed by the transfer of electrons from one atom to another, resulting in attraction between oppositely charged ions.

Hydrogen bond

A relatively weak chemical attraction between partially charged regions of molecules, essential for maintaining DNA and protein structures.

Brønsted-Lowry Acid

A substance that acts as a proton ($H^+$) donor.

Brønsted-Lowry Base

A substance that acts as a proton ($H^+$) acceptor.

Primary protein structure

The specific linear sequence of amino acids joined by peptide bonds in a protein.

Secondary protein structure

Local folding patterns of a polypeptide chain, such as $\beta$-sheets.

Tertiary protein structure

The overall three-dimensional shape of a single polypeptide chain.

Quaternary protein structure

The structural combination of two or more individual polypeptide chains.

Starch

The primary storage polysaccharide form of glucose in plants.

Glycogen

The primary storage polysaccharide form of glucose in animals and many microorganisms.

Cellulose

A structural polysaccharide that forms the primary component of plant cell walls.

Chitin

A structural polysaccharide found in fungal cell walls and arthropod exoskeletons.

Saturated fatty acid

A fatty acid containing no carbon-carbon double bonds ($C=C$), saturated with hydrogen atoms, and typically solid at room temperature.

Unsaturated fatty acid

A fatty acid containing one or more carbon-carbon double bonds ($C=C$), typically liquid at room temperature.

Thymine

A pyrimidine nitrogenous base present in DNA, but replaced by uracil in RNA.

Uracil

A pyrimidine nitrogenous base present in RNA that substitutes for thymine during RNA synthesis.

Prokaryotic cell

A cell lacking a membrane-bound nucleus and membrane-bound organelles, typically containing a single circular chromosome in a nucleoid and $70\text{S}$ ribosomes.

Chemotaxis

Directed cell movement toward chemical attractants or away from repellents.

Monotrichous

A flagellar arrangement consisting of a single flagellum at one end of the cell.

Lophotrichous

A flagellar arrangement consisting of a tuft of flagella at one end of the cell.

Amphitrichous

A flagellar arrangement consisting of single or multiple flagella at both ends of the cell.

Peritrichous

A flagellar arrangement where flagella are distributed across the entire cell surface.

Fimbriae

Hair-like bacterial surface appendages used primarily for adherence to surfaces.

Sex pilus

A specialized bacterial appendage used for conjugation and transfer of DNA between cells.

Capsule / Glycocalyx

An outer bacterial surface layer responsible for cell adherence and protection against host immune responses.

Plasmid

Extra-chromosomal DNA element in bacteria that often carries non-essential genes such as antibiotic-resistance genes.

Endospore

A dormant, non-metabolically active survival structure produced by certain bacteria under unfavorable conditions, highly resistant to heat and chemicals and rich in calcium dipicolinate.

Lipid A

The toxic endotoxin component of lipopolysaccharide (LPS) in Gram-negative bacteria that induces inflammatory responses such as fever.

Gram-positive cell wall

A bacterial cell wall characterized by a thick peptidoglycan layer containing teichoic and lipoteichoic acids, lacking an outer membrane.

Gram-negative cell wall

A bacterial cell wall composed of a thin peptidoglycan layer, a periplasmic space, and an outer membrane containing lipopolysaccharide (LPS).

Gram stain sequence

A differential staining procedure using Crystal violet (primary stain), Iodine (mordant), Alcohol/acetone (decolorizer), and Safranin (counterstain).

Darkfield microscopy

A light microscopy technique that produces bright specimens against a dark background, ideal for observing thin, live, unstained cells like spirochetes.

Acid-fast stain

A differential stain used to identify Mycobacterium species, which possess cell envelopes rich in mycolic acid.

Simple diffusion

The passive movement of solute particles down their concentration gradient across a membrane without transport proteins or ATP.

Facilitated diffusion

The passive movement of substances down their concentration gradient across a membrane requiring transport proteins, but not ATP.

Plasmolysis

The shrinkage of a cell's cytoplasm away from the cell wall caused by water loss in a hypertonic environment.

Catabolism

Metabolic processes that break down complex organic molecules into simpler ones, generally releasing energy.

Anabolism

Metabolic processes that synthesize complex cellular components from simpler building blocks, requiring energy input.

Enzymes

Biological protein catalysts that speed up biochemical reactions by lowering activation energy.

Glycolysis

The initial metabolic pathway for glucose breakdown that converts glucose to pyruvate without requiring oxygen.

Aerobic respiration

A metabolic pathway requiring oxygen as the final electron acceptor that generates a large yield of ATP per glucose.

Fermentation

An anaerobic metabolic process yielding low amounts of ATP without oxygen, generating end products such as lactic acid.

Obligate aerobe

An organism that requires oxygen for cellular respiration and survival.

Obligate anaerobe

An organism for which oxygen is toxic; it grows only in environments devoid of oxygen.

Facultative anaerobe

An organism capable of growing with or without oxygen.

Microaerophile

An organism that requires oxygen at lower concentrations than atmospheric levels.

Lag phase

The bacterial growth curve phase where cells adapt to new environmental conditions with minimal increase in cell count.

Log phase

The bacterial growth phase characterized by rapid, exponential cell division at a constant rate.

Stationary phase

The growth phase where the rate of new cell division equals the rate of cell death due to nutrient exhaustion and waste accumulation.

Death phase

The growth phase where the rate of cell death exceeds the rate of new cell production.

Selective medium

Culture media designed to inhibit the growth of unwanted microbes while encouraging the growth of desired organisms.

Differential medium

Culture media used to distinguish between different groups of bacteria based on observable colony colors or biochemical reactions.

MacConkey agar

A selective and differential medium that selects for Gram-negative bacteria and differentiates lactose fermenters from non-fermenters.

Sterilization

The complete destruction or removal of all viable microorganisms, including bacterial endospores.

Disinfection

The destruction or removal of vegetative pathogens from inanimate surfaces, which may not kill endospores.

Antisepsis

The application of chemical agents to living tissue to destroy or inhibit vegetative pathogens.

Bactericidal

Refers to antimicrobial treatments or agents that directly kill bacteria.

Bacteriostatic

Refers to antimicrobial treatments or agents that inhibit bacterial growth without directly killing the cells.

Decimal Reduction Time (DRT)

The time required at a specific temperature to eliminate $90\%$ of a microbial population.

Autoclave

A sterilization apparatus using steam under pressure; indicator tape showing dark lines confirms heat exposure but not guaranteed sterility.

Use-dilution test

A standard experimental method used to evaluate the efficiency of chemical disinfectants on inanimate surfaces.