Microbiology: Prokaryotic and Eukaryotic Cell Structures

Vocabulary practice flashcards covering cell anatomy, bacterial cell wall structures, flagellar arrangements, and transport mechanisms based on the lecture notes.

Prokaryote

A type of organism characterized by simple cell structure that lacks a nucleus and internal membrane-bound organelles.

Eukaryote

A complex cellular organism containing a true nucleus and internal membrane-bound organelles.

Mycoplasma

The smallest free-living microbe, which is nonmotile and capable of carrying out all essential processes of life.

Glycocalyx

A gelatinous, sticky substance surrounding the outside of the cell wall composed of polysaccharides, polypeptides, or both.

Capsule

A firmly attached glycocalyx made of organized repeating units of organic chemicals that allows bacteria to hide from host defenses.

Slime layer

A loosely attached, water-soluble glycocalyx layer that enables prokaryotes to attach to surfaces.

Types of Flagella

Arrangements of bacterial flagella including Monotrichous, Lophotrichous, Amphitrichous, and Peritrichous.

Taxis

Bacterial movement in response to external stimuli, executed through alternating runs and tumbles.

Fimbriae

Sticky, bristlelike cellular extensions shorter than flagella that help bacteria adhere to one another and form biofilms.

Pili

A specialized type of fimbriae (such as conjugation pili) longer than standard fimbriae but shorter than flagella.

Bacterial Cell Shapes

Morphological classifications of bacteria, including spherical Cocci, rod-shaped Bacilli, and spiral-shaped Spirilla.

Gram-Positive and Gram-Negative Cell Walls

Bacterial cell wall structures distinguished by a thick peptidoglycan layer with teichoic acids in Gram-positive cells, versus a thin peptidoglycan layer with an outer membrane containing lipopolysaccharides in Gram-negative cells.

Mycolic acid

A lipid present in up to $60\%$ concentrations in acid-fast bacteria that helps protect cells from desiccation.

Group translocation

An active transport process in bacteria in which a substance is chemically modified while being transported across the membrane.

Endospores

Dormant, highly resistant structures formed by certain bacteria as a defensive strategy against unfavorable environmental conditions.

Hami

Grappling hook-like attachments found on some archaea that function in adhering to surfaces.

Endocytosis and Exocytosis

Active bulk transport processes where endocytosis brings materials into the cell by membrane engulfment, and exocytosis expels materials outside by vesicle fusion.

Lysosome

A eukaryotic membrane-bound organelle containing catabolic enzymes responsible for intracellular cleanup and degradation.

Golgi body

An organelle composed of flattened phospholipid sacs that receives, processes, and packages large molecules into secretory vesicles.

Endosymbiotic Theory

The proposition that eukaryotic cells evolved from the symbiotic union of small aerobic prokaryotes inside larger anaerobic prokaryotes.