Prokaryotic Cell Structure and Microbiology for Nursing Practice

Vocabulary flashcards covering key terms from the lecture notes on cellular and acellular microorganisms, their structures, and related nursing practice concepts.

Prokaryotes

Cells lacking a true nucleus and membrane-bound organelles; include bacteria and archaea.

Eukaryotes

Cells with a true nucleus and membrane-bound organelles; include algae, fungi, and protozoa.

Glycocalyx

External layer of polysaccharides surrounding some bacteria; appears as capsule (organized) or slime layer (loose); aids in adhesion and protection.

Capsule

Organized polysaccharide layer around some bacteria; protects against phagocytosis.

Slime layer

Loose, unorganized polysaccharide layer that aids adhesion to surfaces.

Biofilm

Community of bacteria embedded in extracellular matrix; shields bacteria from stress and enables communication.

Peptidoglycan

Rigid polymer forming the bacterial cell wall; thickness and resistance differ between Gram-positive and Gram-negative bacteria.

Gram-positive bacteria

Bacteria with a thick peptidoglycan layer and no outer membrane; stain purple in Gram staining.

Gram-negative bacteria

Bacteria with a thin peptidoglycan layer and an outer membrane containing lipopolysaccharide; periplasmic space.

Outer membrane

Lipid bilayer in Gram-negative bacteria enclosing the periplasm; contains porins and lipopolysaccharide.

Lipopolysaccharide (LPS)

Endotoxin-containing molecule in the Gram-negative outer membrane; consists of lipid A and O-antigen.

Lipid A

Endotoxic component of LPS that anchors LPS in the outer membrane.

Porin

Protein channels in the outer membrane that regulate molecule passage.

Teichoic acid

Anionic polymers in Gram-positive cell walls contributing to charge and rigidity.

Lipoteichoic acid

Teichoic acids anchored to the cytoplasmic membrane in Gram-positive bacteria.

Cytoplasmic (cell) membrane

Phospholipid bilayer surrounding the cytoplasm; selectively permeable; site of various metabolic activities.

Cytoplasm

Aqueous interior of the cell where the cytosol is located; site of glycolysis in bacteria.

Nucleoid

Region containing the bacterial chromosome; not enclosed by a membrane.

Chromosome (bacterial)

Circular double-stranded DNA carrying essential genes.

Plasmid

Small, circular DNA carrying advantageous traits (e.g., antibiotic resistance); transferable between bacteria.

Ribosome (bacterial 70S)

Molecular complex for protein synthesis in bacteria (composed of 50S and 30S subunits).

Flagellum

Whip-like appendage that enables bacterial motility by rotation.

Pili and Fimbriae

Thin tubes for adherence to surfaces; fimbriae aid adhesion; sex pili (conjugation) transfer DNA.

Endospore

Dormant, tough, non-reproductive structure formed by some bacteria to survive harsh conditions (e.g., Bacillus, Clostridium).

Virus

Acellular infectious agent with a genome (DNA or RNA) enclosed in a protein coat; some have lipid envelopes; requires a host cell to replicate.

Virion

Complete virus particle outside a host cell; contains genome and capsid; may be enveloped.

Capsid

Protein shell that encloses the viral genome.

Envelope

Lipid membrane around some viruses derived from the host; contains viral spikes.

Spikes

Viral glycoproteins on the envelope that mediate attachment and entry into host cells.

Bacteriophage

Virus that infects bacteria; can be non-enveloped or enveloped depending on type.

Non-enveloped virus

Virus lacking a lipid envelope; generally more resistant to environmental conditions.

Enveloped virus

Virus with a lipid envelope surrounding the capsid; entry often via fusion or endocytosis.

PCR (polymerase chain reaction)

Molecular technique to amplify a specific DNA segment for detection of pathogens.

Susceptibility testing

Laboratory assessment to determine which antibiotics inhibit a microbe; guides antimicrobial therapy.