Microbiology Fundamentals: Bacteria, Archaea, Eukaryotes, and Microbial Growth

Vocabulary flashcards covering prokaryotic and eukaryotic structures, taxonomy, nutritional categories, environmental adaptations, and microbial growth dynamics from Chapters 3, 4, and 6.

Nucleoid

The nuclear region in bacteria and archaea where DNA is aggregated free in the cytoplasm without being enclosed by a nuclear membrane or wrapped around histones.

Virus vs. Bacteria

Virus- tiny, nonliving, infectious made of protein coat and genetic material

Bacteria- complete, living cell with ribosomes

Cyst

Dormant stage, protects protozoa from harsh environments and allows them to survive

Trophozoite

Being active, feeding, and multiplying

Fungal reproduction

Reproduce by spores or through budding

Hyphae

Long, thread-like filamentous structures in fungal cells

Fungi benefits

Help decompose organic matter, help plants absorb nutrients and produce food like beer, bread, antibiotics

Demorphic fungi

Change between 2 forms like moldand yeast depending on the temperature

Yasta

Single, round/oval cells in fungal cells

Mitochondria

Powerhouse of eukaryotic cells, generate ATP through cellular respiration

Chloroplasts

Capture sunlight to perform photosynthesis, found in plants and alge

Inclusions

Storage bodies for nutrients

Cytoplasm

Jelly-like fluid filling the cell interior

Gram-Negative

Thin peptidoglycan layer, an outtrr membrane coating lipopolysaccharides, and an inner cytoplasmic membrane

Gram-Positive

Thick peptidoglycan layer and an inner cytoplasmic membrane, has a thicker wall with a dense layer of cross-linked peptidoglycan which makes it stronger

Peptidoglycan

A network composed of long glycan chains with alternating sugar molecules ($N$-acetylglucosamine and $N$-acetylmuramic acid) cross-linked by short peptide chains that gives rigidity and structural support to bacterial cell walls.

Bacterial motility

Bacteria move primarily by rotating their flagella, or using twitching motility

Coccus

A bacterial cell that is spherical or ball-shaped.

Bacillus

A bacterial cell that is cylindrical or rod-shaped.

Coccobacillus

A bacterial cell shape characterized as a short, plump rod.

Vibrio

A singly occurring, gently curved rod-shaped bacterium.

Spirillum

A bacterium having a slightly curled or spiral-shaped body.

Diplococci

Spherical bacterial cells occurring in pairs.

Tetrad

A group of four spherical bacterial cells resulting from division in two perpendicular planes.

Staphylococci

Irregular clusters of spherical bacterial cells.

Streptococci

Chains of spherical bacterial cells ranging from a few to hundreds of cells.

Sarcina

A cubical packet of eight, sixteen, or more spherical bacterial cells.

Diplobacilli

A pair of rod-shaped bacterial cells with their ends attached.

Streptobacilli

A chain of several rod-shaped bacterial cells.

Palisades

An arrangement of rod-shaped cells in a chain where cells remain partially attached by a small hinge region at the ends.

Chemotaxis

The movement of bacteria in response to chemical signals, characterized as positive chemotaxis when moving toward a favorable stimulus or negative chemotaxis when moving away from a repellent.

Flagella

Used for motility

Fimbriae

Small, brissel-like fibers sprouting off the surface of many bacterial cells that allow tight adhesion to epithelial cells and host surfaces.

Pili

Long, rigid tubular appendages used in conjugation between bacterial cells to transfer DNA.

S Layer

A single layer composed of thousands of copies of a single protein produced by bacteria for protection or attachment only when in hostile environments.

Glycocalyx

An outer surface coating composed of repeating polysaccharide or glycoprotein units that serves protective, adhesive, and receptor functions.

Lipopolysaccharide (LPS)

A complex molecule in the outer membrane of Gram-negative bacteria containing Lipid A, an endotoxin that causes fever and shock during infection.

Mycolic Acid

A waxy lipid component found in the cell walls of acid-fast bacteria such as Mycobacterium and Nocardia that contributes to resistance against chemicals and dyes.

Mycoplasmas

Bacteria that naturally lack a cell wall entirely, such as Mycoplasma pneumoniae.

Plasmids

Small, usually circular double-stranded DNA molecules in bacteria that exist separate from the chromosome and carry extra genes conferring traits like drug resistance.

Endospore

A highly resistant, dormant body formed within certain bacterial species (e.g., Bacillus, Clostridium) that enables survival during extreme heat, drying, radiation, and chemical exposure.

Sporulation

The process by which a vegetative bacterial cell converts into a mature endospore upon nutrient depletion.

Gracilicutes

A major division of bacteria in Bergey's Manual that possess Gram-negative cell envelopes with thin cell walls.

Firmicutes

A major division of bacteria in Bergey's Manual that possess Gram-positive cell envelopes with thick, strong cell walls.

Tenericutes

A major division of bacteria in Bergey's Manual that lack a cell wall and are soft-bodied.

Mendosicutes

A major division in Bergey's Manual comprising archaea with primitive characteristics, unusual cell walls, and distinct nutritional habits.

Serotype

A strain or group of bacteria within the same species that possess unique surface molecules (antigens) and elicit a specific antibody response.

Eukaryotic Cilia

Short, numerous cell membrane extensions found on specific protozoa and animal cells that aid in locomotion and propulsion.

Chitin

A tough polysaccharide forming the thick inner layer of fungal cell walls.

Nucleolus

A dense region within the eukaryotic nucleoplasm that serves as the site for ribosomal RNA synthesis and ribosomal subunit assembly.

Rough Endoplasmic Reticulum (RER)

A membrane network studded with ribosomes that transports synthesized proteins from the nucleus toward the cytoplasm and Golgi apparatus.

Smooth Endoplasmic Reticulum (SER)

A membrane network lacking ribosomes that functions in lipid synthesis, nutrient processing, and storage of nonprotein macromolecules.

Golgi Apparatus

An organelle consisting of flattened, disc-shaped sacs called cisternae where proteins received from the RER are modified, packaged, and sorted into vesicles.

Lysosome

A membrane-bound vesicle originating from the Golgi apparatus containing digestive enzymes for intracellular nutrient breakdown and protection against pathogens.

Cristae

The folded inner membranes of mitochondria that hold enzymes and electron carriers required for aerobic respiration and ATP generation.

Macronutrients

Essential chemical elements required by microbes in relatively large amounts, including carbon, hydrogen, oxygen, nitrogen, phosphorus, and sulfur (CHONPS).

Micronutrients

Trace elements required by microbes in small amounts, such as iron, zinc, manganese, and nickel, which assist enzymes or stabilize protein structures.

Heterotroph

An organism that relies on organic molecules as its primary source of carbon.

Autotroph

An organism that utilizes inorganic carbon dioxide ($\text{CO}_2$) as its primary carbon source.

Chemoheterotroph

An organism that derives both its carbon and energy from organic molecules absorbed from host tissues or external organic matter.

Plasmolysis

The process in which water diffuses out of a bacterial cell in a hypertonic environment, causing the cytoplasmic membrane to shrink away from the cell wall.

Psychrotrophs

Microorganisms that are capable of growing slowly at low temperatures, such as inside a refrigerator (e.g., Listeria monocytogenes).

Mesophiles

Organisms that grow optimally at moderate temperatures (20^\n\circ\text{C} to $40^\circ\text{C}$), including most human pathogens.

Thermoduric

Microbes that normally inhabit moderate temperatures but can survive short bursts of exposure to high heat.

Obligate Aerobe

An organism that strictly requires oxygen for growth and survival.

Facultative Anaerobe

An organism that uses oxygen when available but can switch to anaerobic metabolic modes when oxygen is absent.

Obligate Anaerobe

An organism that cannot tolerate oxygen and is destroyed or inhibited in its presence.

Microaerophile

An organism that requires oxygen to survive but only at concentrations lower than normal atmospheric levels.

Aerotolerant Anaerobe

An organism that does not utilize oxygen for energy production but can survive and grow in its presence.

Parasitism

A symbiotic relationship where one organism benefits at the direct expense and harm of the host.

Synergism

A nonsymbiotic relationship between free-living organisms that cooperate and share nutrients.

Antagonism

A nonsymbiotic relationship in a community where some members produce substances that inhibit or destroy competing species.

Quorum Sensing

A system of chemical signaling used by bacteria within biofilms to monitor population density and coordinate group behavior.

Binary Fission

The primary mode of asexual bacterial reproduction in which one cell divides into two equal, genetically identical daughter cells.

Lag Phase

The initial period in a bacterial growth curve where cells adapt to their new environment and synthesize necessary molecules without increasing total cell count.

Log Phase

The exponential growth phase in a bacterial culture where cells divide at a maximum and constant rate.