Module 1 - Vocab

An observable output of an organism’s genotype plus the environment

Phenotype

A category of measurement method that counts the number of cells to determine the phenotype

Direct

A category of measurement method that estimates the number of cells by examining by-products or features but not directly counting the cells

Indirect

Pathway that breaks down materials to release energy

Catabolic pathway

Pathway that uses energy to make products

Anabolic pathway

Molecule that is broken down to make ATP

Energy source

Molecule broken down into carbon molecules to use in synthesis of cell structures

Carbon source

An electrical gradient that powers ATP synthase

Membrane potential

Manipulated variable

A variable that is changed by the researcher in an experiment

Response variable

Variable that changes in response to the manipulated variable and whose response is measured during the experiment

A sample with established characteristics

Control sample

Positive control

A treatment or sample in an experiment that should create measurable change in the assay

Negative control

A sample in an experiment that should cause no change in the assay

Nutrients and agar form a gel substrate in a Petri dish. Bacteria cells grow on top of the substrate

Solid culture

What is a matrix?

Nutrient and agar base of a solid culture

Nutrients dissolved in water form a broth inside a culture tube or flask. Bacteria grow in the broth.

Liquid culture

Assay that determines survival of a bacterial population in response to a manipulated variable

Viability assay

Assay measuring the rate of growth of a bacterial population over time in response to a manipulated variable

Growth curve assay

Direct method for determining the size of a population

Viable count method

Serial dilution

Original inoculum is diluted several times in the procedure to produce cultures with differing numbers of colonies

A visible aggregation of bacterial cells on a surface that arose from a single parent cell

Colony

A unit of measure that estimates the number of viable bacterial cells in a sample

Colony forming unit (CFU)

Growth curve

A plot of the change in size of the bacterial population over time

Inoculate

To add cells to a culture

A period where the binary fission rate is equal to the death rate of the population as cells metabolically adjust to a new culture conditions

Lag phase

The length of time it takes for a cell to grow and divide

Generation time

A period when cellular reproduction and metabolic activity is maximized resulting in maximum cell growth and the rate of binary fission is greater than that of cell death

Log (exponential) phase

A period where the rate of binary fission is equal to the rate of cellular death bring the population into equilibrium

Stationary phase

Period where rate of cellular death is greater than rate of binary fission

Death phase

Bacterial growth in a disk diffusion test after incubation?

Lawn

Assay that measures the product of an enzyme to determine the effects of the manipulated variable

Enzyme assay

Lowest antibiotic concentration that prevents visible bacteria growth

Minimal inhibitory concentration (MIC)

Lowest amount of drug required to kill bacteria

Minimal bactericidal concentration (MBC)

Bacteriostatic

Drug that inhibits bacterial development

Bactericidal

Drug that kills bacteria

Recording of susceptability of bacteria encountered

Antibiogram

A type of cell with membrane bound organelles

Eukaryotic cell

A type of cell without intercellular structures - type of cell of most bacteria

Prokaryotic cell

How DNA is copied into mRNA through transcription and mRNA is used to code polypeptide chains through translation

Central dogma of molecular biology

The genome of the entire cell and all of the genes that it contains

Genotype

The original genome of a species that is often used as a control in experiments

Wildtype

Using multiple stains of different colors to distinguish different types of microorganism

Differential stains

Cell wall

A complex, semi-ridged structure that protects and maintains the shape of the cell

A lattice that is made up of a disaccharide backbone, connected by polypeptides that makes up the cell wall in most bacteria

Peptidoglycan

Bond between N-acetylglucosamine and N-acetylmuramic acid that creates a beta-1, 4 linkage in peptidoglycan

Glycosidic bond

General term for polymers of sugar

Glycan

Murein Sacculus

Massive molecule of peptidoglycan that completely surrounds the cell

Connects the outer membrane in gram (-) cells to the peptidoglycan layer

Lipoprotein

Teichoic acids

Polymers of repeating ribitol or glycerol phosphate that reinforces peptidoglycan of gram (+) cells and create a negative charge to assist in binding positively charged ions prior to intramembrane transport

Lipoteichoic acid

Teichoic acids that are covalently connected to plasma membrane lipids to reinforce the peptidoglycan layer in gram (+) cells

Outer membrane

A membrane composed of lipopolysaccharides, lipoproteins, and phospholipids that forms a layer of protection of the thin layer of peptidoglycan in gram (-) bacteria

Lipopolysaccharide

Chains of polysaccharides connected to fatty acids enbedded in gram (-) cell walls

Lipid A

Fatty acid with a disaccharide that is embedded in the top layer of the outer membrane and is released as an endotoxin when the bacteria dies

Endotoxin

Lipid A part of the LPS that is responsible for infection symptoms including fever, dilation of blood vessels, shock and blood clotting

Core polysaccharide

Chain of unusual sugars that provides the structural component of LPS

O-specific polysaccharide

Composed of sugar molecules and acts as an antigen

Distinct variation of a bacteria cell based on it’s antigen, can be determined through diagnostic tests

Serotype

Porins

Trimeric tube-like proteins of the outer membrane in gram (-) cells that transport materials into and out of the cell

Antigen

Something that is recognized by the immune system, can be used for identification

Stain that only uses one dye and stain all cells the same color - intended to highlight the entire organism by increasing contrast

Simple staining

Thin film of material containing micro-organisms that is not so dilute that cells cannot be found but not so thick that cells are on top of each other

Smear

Dye with positively charged colored salts that bind to the negative charge on bacteria

Basic dyes

Chromosphore

Pigmented salt in stains

Acidic dyes

Negatively charged salts in stains that are repealed from bacteria

Preparing colorless bacteria on a colored background

Negative staining

Chemical added to intensify stain by increasing the affinity of the stain for the specimen or to coat a structure to increase visibility

Mordant

Staining technique that distinguishes gram (+) from Gram (-) bacteria

Gram staining

Degree to which a pathogen can cause disease

Virulence

Endospore

Relatively uncommon in bacteria - special resistant structures that protect it from adverse environmental conditions

Typical spherical cell with only a plasma membrane, usually still able to metabolize nutrients

Protoplast

Member of the proteus genus that can lose their cell walls and swell to an irregular shape but can still live and divide

L-form

Cell with cellular contents, plasma membrane and partial cell wall

Spheroplast

Intracellular structures composed of stored nutrients that may or may not be surrounded by a membrane

Inclusions

Highly compact, aggregated structure of genomic DNA in prokaryotes which contains specific proteins

Nucleoid

Enzyme in prokaryotes that breaks one strand of DNA in to rotate it around and seal it into supercoiled circular DNA strands

Topoisomerases

Internal ridged structures attached to one end of protoplasmic cylinder and contained within an flexible outer sheath in spirochete bacteria that rotate the entire cell, allowing motility

Endoflagella or axial filaments

Glycogen

Large, branched polymers of glucose

Polyphosphate granules

Inclusions of a linear polymer of phosphate esters used to store energy and phosphates

Sulfur granules

Inclusions of elemental sulfur used to store energy in prokaryotes that metabolize sulfur

Gas Vesicles

Hollow, protein covered cylinders occurring in bundles which provide buoyancy to the cell

Endospores

Highly durable dehydrated cells formed by certain species of gram (+) vegetative cells during unfavorable conditions which can survive for thousands of years, through extreme heat, dehydration, toxic chemical, radiation, etc

Process by which an endospore is formed

Sporulation

Vegetative

Growing cells capable of metabolization and replication

Process in which an endospore is converted back to a vegetative cell

Germination

Laboratory species of bacteria used to better understand endospores

Bacillus subtilis

Outermost covering of an endospore mainly consisting of proteins

Exosporium

Internal layer of proteins in endospores between the exosporium and the cortex

Spore coats

Peptidoglycan layer in endospores

Cortex

Interior of an endospore containing DNA, RNA, and ribosomes

Core

Forms complexes with calcium in the core to protect DNA form damage in endospores

Dipicolinic Acid

Proteins stable to heat, radiation, chemicals, etc in endospores

Spore acid-soluble proteins

Intercellular structures consisting of protein subunits enclosed in enzymes which perform CO2 fixation with photosynthesis to make sugars

Carboxysomes

Coils of DNA into a highly compact conformation which takes up less volume

Supercoils

Vesible

A small area surrounded by a membrane bilayer consisting of the same material as a plasma membrane

Proteins that lie on the inner or outer surface of the plasma membrane

Peripheral proteins

Proteins of that fully penetrate the plasma membrane

Transmembrane or integral proteins

Proteins bound to carbohydrates

Glycoproteins

Lipids bound to carbohydrates

Glycolipid

Dynamic array of proteins and phospholipids in the cytoplasmic membrane?

Fluid mosacic model

Selective permeability

Certain molecules and ions can easily pass into and out of the cell while others are stopped