WGU D311 Microbiology Bacterial Structures and Cellular Processes
Complete Study Guide with Detailed Notes, Nucleoid and Plasmid
Functions, Ribosomes and Protein Synthesis, Inclusions and Storage
Mechanisms, Endospore Formation and Resistance, Plasma
Membrane Structure, Cell Wall Composition, Gram Positive and
Gram Negative Differences, Flagella Motility, Fimbriae and Pili
Functions, Chemotaxis and Phototaxis, Bacterial Movement
Patterns, Sporulation Process Steps, Vegetative Cells, Survival
Mechanisms Practice Exam Questions Verified and Provided with
Complete A+ Graded Answers Latest Updated 2026
Bacterial Structures: Nucleoid
Irregular shaped region within the cell of a prokaryote that contains all or most of the genetic
material
Bacterial Structures: Plasmids
Small, circular, double-stranded DNA molecules found in prokaryotic cells along side the main
chromosomes; often carry genes, including antibiotic resistance to aid in organism survival
Bacterial Structures: Ribosomes
Responsible for protein synthesis:
Prokaryotes - have 70S in cytoplasm
Eukaryotes - have multiple located throughout the cytoplasm and by ER
,Bacterial Structures: Inclusions
Some prokaryotic cells store excess nutrients in these structures, aiding adaption to unstable
environments by reducing osmotic pressure
Bacterial Structures: Endospores
Are specialized structures formed by certain bacteria to protect their genetic material in a
dormant state during unfavorable conditions; Ex: archaea
Bacterial Structures: Plasma Membrane
Present in all cells, encloses the cytoplasm, internal structures, and regulates molecule
passage; consists of lipids and proteins that move fluidly:
Prokaryotes: Nuclear Envelope
Bacterial Structures: Cell Wall
Protects the cells from harsh environmental conditions; Bacteria: primarily comprised by
peptidoglycan, while archaea have pseudopeptidoglycan or other structures;
Gram-positive: have thick peptidoglycan layers containing teichoic acids
Gram-negative: have thinner peptidoglycan layers with an outer membrane containing
lipoplycaccharides
Bacterial Structures: Flagella
Cell structure that enable movement in liquid environment
,Bacterial Structures: Fimbriae
Short bristle-like proteins projecting from the cell surface to attach to surfaces and other cells;
important for biofilm formation
Pathogenic: important for colonization, infectivity, and virulence
Bacterial Structures: Pili
longer, less numerous protein appendages that aid in attachment to surfaces; important in
transfer of DNA between bacterial cells
Chemotaxis
Cell movement in response to chemical signals in their environment
Positive Chemotaxis
Detection of a concentration gradient of a specific chemical that can be attracted
Negative Chemotaxis
Detection of a concentration gradient of a specific chemical that can be repelled
Phototaxis
Cell movement in response to light
, Positive Phototaxis
Movement toward lights
Negative Phototaxis
Movement away from lights
Bactrium "runs"
Flagella propelling bacteria forward in counterclockwise motion toward stimuli
Bactrium "tumbles"
Flagella rotating clockwise to stop bacterium and change direction randomly by reorientation
and exploration of environment
Endospores
Dormant, highly resistant structures from by certain bacteria in response to adverse
environmental conditions
Vegetative Cells
Actively growing and metabolically active bacteria cells; lack resistance properties of
endospores and are susceptible to environmental stressors; carry out normal functions such
as metabolism, growth, and reporoduction
Complete Study Guide with Detailed Notes, Nucleoid and Plasmid
Functions, Ribosomes and Protein Synthesis, Inclusions and Storage
Mechanisms, Endospore Formation and Resistance, Plasma
Membrane Structure, Cell Wall Composition, Gram Positive and
Gram Negative Differences, Flagella Motility, Fimbriae and Pili
Functions, Chemotaxis and Phototaxis, Bacterial Movement
Patterns, Sporulation Process Steps, Vegetative Cells, Survival
Mechanisms Practice Exam Questions Verified and Provided with
Complete A+ Graded Answers Latest Updated 2026
Bacterial Structures: Nucleoid
Irregular shaped region within the cell of a prokaryote that contains all or most of the genetic
material
Bacterial Structures: Plasmids
Small, circular, double-stranded DNA molecules found in prokaryotic cells along side the main
chromosomes; often carry genes, including antibiotic resistance to aid in organism survival
Bacterial Structures: Ribosomes
Responsible for protein synthesis:
Prokaryotes - have 70S in cytoplasm
Eukaryotes - have multiple located throughout the cytoplasm and by ER
,Bacterial Structures: Inclusions
Some prokaryotic cells store excess nutrients in these structures, aiding adaption to unstable
environments by reducing osmotic pressure
Bacterial Structures: Endospores
Are specialized structures formed by certain bacteria to protect their genetic material in a
dormant state during unfavorable conditions; Ex: archaea
Bacterial Structures: Plasma Membrane
Present in all cells, encloses the cytoplasm, internal structures, and regulates molecule
passage; consists of lipids and proteins that move fluidly:
Prokaryotes: Nuclear Envelope
Bacterial Structures: Cell Wall
Protects the cells from harsh environmental conditions; Bacteria: primarily comprised by
peptidoglycan, while archaea have pseudopeptidoglycan or other structures;
Gram-positive: have thick peptidoglycan layers containing teichoic acids
Gram-negative: have thinner peptidoglycan layers with an outer membrane containing
lipoplycaccharides
Bacterial Structures: Flagella
Cell structure that enable movement in liquid environment
,Bacterial Structures: Fimbriae
Short bristle-like proteins projecting from the cell surface to attach to surfaces and other cells;
important for biofilm formation
Pathogenic: important for colonization, infectivity, and virulence
Bacterial Structures: Pili
longer, less numerous protein appendages that aid in attachment to surfaces; important in
transfer of DNA between bacterial cells
Chemotaxis
Cell movement in response to chemical signals in their environment
Positive Chemotaxis
Detection of a concentration gradient of a specific chemical that can be attracted
Negative Chemotaxis
Detection of a concentration gradient of a specific chemical that can be repelled
Phototaxis
Cell movement in response to light
, Positive Phototaxis
Movement toward lights
Negative Phototaxis
Movement away from lights
Bactrium "runs"
Flagella propelling bacteria forward in counterclockwise motion toward stimuli
Bactrium "tumbles"
Flagella rotating clockwise to stop bacterium and change direction randomly by reorientation
and exploration of environment
Endospores
Dormant, highly resistant structures from by certain bacteria in response to adverse
environmental conditions
Vegetative Cells
Actively growing and metabolically active bacteria cells; lack resistance properties of
endospores and are susceptible to environmental stressors; carry out normal functions such
as metabolism, growth, and reporoduction
