BIOL 203 Microbiology LCC Final – Accurate Study Guide
& Exam Prep (2025/2026)
“Ace your BIOL 203 Microbiology Final at LCC with this detailed study guide. Includes
accurate, exam-style questions and answers based on course objectives.”
Name one cellular component or structure of a prokaryotic cell that would make it more virulent (able
to cause disease) than a prokaryotic cell that does not have that component or structure.
Explain what the component or structure does and how it contributes to virulence of the organism.
All prokaryotic cells have peptidoglycan/cell wall. It doesn't make them more likely to cause disease.
Some examples would be fimbriae (used for attaching to host tissue and resisting being washed away by
mucous, etc.), capsules (hide from the immune system), endospores, toxins, etc.
________ are always unicellular, prokaryotic cells. At present, none of them have been shown to be
pathogenic in humans. Many members are capable of living in seemingly inhospitable environments
like salt lakes.
Archaea
_________ are unicellular eukaryotes, known to cause human diseases such as Malaria and African
Sleeping Sickness often transmitted by a vector such as mosquitoes.
Protozoa
______ are unicellular prokaryotes, known to cause a variety of human diseases. If serious, they can
be treated with antibiotics.
Bacteria
______ are photosynthetic eukaryotic cells, can be multicellular or unicellular, and very rarely cause
disease in humans.
Algae
_____ are eukaryotic, can be multicellular or unicellular and can cause diseases such Thrush, Athlete's
foot, and Ringworm.
Fungi
_____ are neither prokaryotes nor eukaryotes and are known to cause diseases such as the common
cold, Ebola, and HIV.
Viruses
,_____ are always multicellular, eukaryotic cells but have microscopic stages in their life cycle. They are
often described as parasites.
Helminthes
site of protein synthesis
ribosomes
gel like substance inside the cell, site of many chemical reactions
cytoplasm
storage of things like glycogen, phosphate, even gas
inclusion/granule
where the main chromosome is located
nuclear region
performs the 'gate keeper' function for the cell, regulates entry and exit of materials into and out of
the cell
cell (plasma) membrane
rigid and porous, gives the cell shape and protects from bursting
cell wall
protects the cell from phagocytosis by the host immune system
capsule
protects the cell from drying out
slime layer
can be used for attachment or conjugation
pili
used for movement
flagella
extrachromosomal DNA, often carries antibiotic resistance
plasmid
This gram-positive, rod shaped bacterium is found in soil. It often looks "drumstick" shaped under the
microscope due to the spores it produces. It is anaerobic and will remain in the spore form until it is in
an environment that lacks oxygen. A puncture wound, where the spores are pushed deep into the skin
can create this perfect environment for the spores to become vegetative and produce a toxin that
causes paralysis.
,Clostridium tetani
This gram-positive, cocci shaped bacteria can be found in chains. It causes Strep Throat as well as
some cases of necrotizing fasciitis. It is often identified in the lab by using a blood agar plate. It is beta
hemolytic and lyses red blood cells producing a clear zone.
Streptococcus pyogenes
This gram-negative, comma shaped bacterium can be found in water. Infection via drinking
contaminated water leads to vomiting and diarrhea. If medical treatment and rehydration are
available then infection is rarely fatal. In parts of the world where medical treatment is not available,
death can occur in less than a week from fluid loss alone.
Vibrio cholerae
This acid-fast, rod shaped bacterium typically infects the lungs of humans because it is aerobic and
requires a high concentration of oxygen. Due to its acid fast cell which allows few things inside, it is
very hard to treat with antimicrobials. A treatment course can last from months to years.
Noncompliance with treatment is common and has led to the spread of multidrug and extreme drug
resistant strains.
Mycobacterium tuberculosis
This gram-negative bacterium is a rod shaped coccobacillus carried by fleas. The fleas don't typically
bite humans, but the bacterium blocks their throat preventing blood from reaching their stomachs. In
this state of perpetual hunger, they will bite anything that is near. Each time they bite, they
regurgitate some of their stomach contents (and the bacterium) into the new host. Infected humans
may develop black, necrotic lymph nodes visible through the skin giving this disease the nickname,
"The Black Plague."
Yersinia pestis
This gram-negative, coccus shaped bacterium is typically found in pairs called diplococci. It causes
serious infection of the brain and spinal cord. It is considered fastidious and often grown on Chocolate
Agar (agar that includes cooked blood.) There is a vaccine that is highly recommended for college
students living in dorms.
Neisseria meningitidis
This gram-negative, coccobacilli bacterium infects the respiratory system and causes a very serious
disease, Whooping Cough, in infants and young children. The name comes from the gasp of air, these
children take in after a prolonged coughing fit. Adults may also become infected (and transmit the
bacterium), but due to their more mature respiratory system, the disease presents as a normal, but
prolonged cough without the "whoop." It can be prevented with the TDaP or DTaP vaccination.
Bordetella pertussis
This gram-positive, cocci shaped bacterium is often found in clusters. It is a common member of the
normal flora of 30% of humans, but can cause a range of skin infections under the right circumstances.
, It is resistant to many antibiotics leaving us with few options for treatment. Vancomycin is the current
drug used to treat it, but since 1996, strains resistant to vancomycin have appeared.
Staphylococcus aureus
This gram-positive, rod shaped bacterium is able to form spores. These spores can be found in the
gastrointestinal tract of many humans. When the gut is healthy (home to normal microbiota members
in sufficient numbers), the spores stay dormant. When the normal microbiota numbers are drastically
reduced, typically following use of a broad spectrum antibiotic, the spores become vegetative and
cause diarrhea. Because antibiotics often make this infection worse rather than better, new treatment
options like fecal transplants are being explored.
Clostridium difficile
This gram-negative, rod shaped bacterium is typically found in water and soil. It is considered an
opportunistic infection and can infect the lungs of cystic fibrosis patients and burn victims. It is
resistant to many antibiotics. It can produce blue green pigment and smell like grapes.
Pseudomonas aeruginosa
What is glucose? How a chemist would describe glucose? Using what you learned about glucose and
what you know about the structure and function of a plasma membrane, Explain why a molecule like
glucose (even in a greater concentration outside the cell compared to inside the cell) cannot cross the
phospholipid bilayer of the plasma membrane and instead must travel through a protein "gate."
Glucose is a simple sugar used as an energy source. A chemist would describe glucose as being an
aldohexose and a monosacaccharide as well as being either linear or cyclic formed. A molecule like
glucose cannot cross the phospholipid bilayer of the plasma membrane and instead needs to travel
through a "gate" because they are too big to diffuse through the plasma membrane.
Explain the concept of osmosis. We know that the process of pickling, adding large amounts of salt,
causes changes in the food itself. A cucumber will shrink into a pickle. But how does adding large
amounts of salt affect microbes that may have contaminated the jar of pickles?
What does the salt do to the spoilage (bad) bacteria?
Osmosis is diffusion of water. Water will move from an area of high water concentration to an area of
low water concentration. Another way to look at it would be to say that water follows solute. If you have
two solutions and one has a high concentration of solute then it also has a low concentration of water. If
the second solution has a low concentration of solute then it has a high concentration of water. If water
were able to move between these two solutions (but solute was not) then water would travel from the
solution with a higher concentration of water to the solution with a lower concentration of water.
Microbes are everywhere and by growing on, consuming, and producing waste products, they spoil our
food. We can slow this process down by heating food up to boiling temperatures to kill all microbes
present and by refrigerating our food to cool enough temperatures that microbial metabolism and
microbial growth slows.
& Exam Prep (2025/2026)
“Ace your BIOL 203 Microbiology Final at LCC with this detailed study guide. Includes
accurate, exam-style questions and answers based on course objectives.”
Name one cellular component or structure of a prokaryotic cell that would make it more virulent (able
to cause disease) than a prokaryotic cell that does not have that component or structure.
Explain what the component or structure does and how it contributes to virulence of the organism.
All prokaryotic cells have peptidoglycan/cell wall. It doesn't make them more likely to cause disease.
Some examples would be fimbriae (used for attaching to host tissue and resisting being washed away by
mucous, etc.), capsules (hide from the immune system), endospores, toxins, etc.
________ are always unicellular, prokaryotic cells. At present, none of them have been shown to be
pathogenic in humans. Many members are capable of living in seemingly inhospitable environments
like salt lakes.
Archaea
_________ are unicellular eukaryotes, known to cause human diseases such as Malaria and African
Sleeping Sickness often transmitted by a vector such as mosquitoes.
Protozoa
______ are unicellular prokaryotes, known to cause a variety of human diseases. If serious, they can
be treated with antibiotics.
Bacteria
______ are photosynthetic eukaryotic cells, can be multicellular or unicellular, and very rarely cause
disease in humans.
Algae
_____ are eukaryotic, can be multicellular or unicellular and can cause diseases such Thrush, Athlete's
foot, and Ringworm.
Fungi
_____ are neither prokaryotes nor eukaryotes and are known to cause diseases such as the common
cold, Ebola, and HIV.
Viruses
,_____ are always multicellular, eukaryotic cells but have microscopic stages in their life cycle. They are
often described as parasites.
Helminthes
site of protein synthesis
ribosomes
gel like substance inside the cell, site of many chemical reactions
cytoplasm
storage of things like glycogen, phosphate, even gas
inclusion/granule
where the main chromosome is located
nuclear region
performs the 'gate keeper' function for the cell, regulates entry and exit of materials into and out of
the cell
cell (plasma) membrane
rigid and porous, gives the cell shape and protects from bursting
cell wall
protects the cell from phagocytosis by the host immune system
capsule
protects the cell from drying out
slime layer
can be used for attachment or conjugation
pili
used for movement
flagella
extrachromosomal DNA, often carries antibiotic resistance
plasmid
This gram-positive, rod shaped bacterium is found in soil. It often looks "drumstick" shaped under the
microscope due to the spores it produces. It is anaerobic and will remain in the spore form until it is in
an environment that lacks oxygen. A puncture wound, where the spores are pushed deep into the skin
can create this perfect environment for the spores to become vegetative and produce a toxin that
causes paralysis.
,Clostridium tetani
This gram-positive, cocci shaped bacteria can be found in chains. It causes Strep Throat as well as
some cases of necrotizing fasciitis. It is often identified in the lab by using a blood agar plate. It is beta
hemolytic and lyses red blood cells producing a clear zone.
Streptococcus pyogenes
This gram-negative, comma shaped bacterium can be found in water. Infection via drinking
contaminated water leads to vomiting and diarrhea. If medical treatment and rehydration are
available then infection is rarely fatal. In parts of the world where medical treatment is not available,
death can occur in less than a week from fluid loss alone.
Vibrio cholerae
This acid-fast, rod shaped bacterium typically infects the lungs of humans because it is aerobic and
requires a high concentration of oxygen. Due to its acid fast cell which allows few things inside, it is
very hard to treat with antimicrobials. A treatment course can last from months to years.
Noncompliance with treatment is common and has led to the spread of multidrug and extreme drug
resistant strains.
Mycobacterium tuberculosis
This gram-negative bacterium is a rod shaped coccobacillus carried by fleas. The fleas don't typically
bite humans, but the bacterium blocks their throat preventing blood from reaching their stomachs. In
this state of perpetual hunger, they will bite anything that is near. Each time they bite, they
regurgitate some of their stomach contents (and the bacterium) into the new host. Infected humans
may develop black, necrotic lymph nodes visible through the skin giving this disease the nickname,
"The Black Plague."
Yersinia pestis
This gram-negative, coccus shaped bacterium is typically found in pairs called diplococci. It causes
serious infection of the brain and spinal cord. It is considered fastidious and often grown on Chocolate
Agar (agar that includes cooked blood.) There is a vaccine that is highly recommended for college
students living in dorms.
Neisseria meningitidis
This gram-negative, coccobacilli bacterium infects the respiratory system and causes a very serious
disease, Whooping Cough, in infants and young children. The name comes from the gasp of air, these
children take in after a prolonged coughing fit. Adults may also become infected (and transmit the
bacterium), but due to their more mature respiratory system, the disease presents as a normal, but
prolonged cough without the "whoop." It can be prevented with the TDaP or DTaP vaccination.
Bordetella pertussis
This gram-positive, cocci shaped bacterium is often found in clusters. It is a common member of the
normal flora of 30% of humans, but can cause a range of skin infections under the right circumstances.
, It is resistant to many antibiotics leaving us with few options for treatment. Vancomycin is the current
drug used to treat it, but since 1996, strains resistant to vancomycin have appeared.
Staphylococcus aureus
This gram-positive, rod shaped bacterium is able to form spores. These spores can be found in the
gastrointestinal tract of many humans. When the gut is healthy (home to normal microbiota members
in sufficient numbers), the spores stay dormant. When the normal microbiota numbers are drastically
reduced, typically following use of a broad spectrum antibiotic, the spores become vegetative and
cause diarrhea. Because antibiotics often make this infection worse rather than better, new treatment
options like fecal transplants are being explored.
Clostridium difficile
This gram-negative, rod shaped bacterium is typically found in water and soil. It is considered an
opportunistic infection and can infect the lungs of cystic fibrosis patients and burn victims. It is
resistant to many antibiotics. It can produce blue green pigment and smell like grapes.
Pseudomonas aeruginosa
What is glucose? How a chemist would describe glucose? Using what you learned about glucose and
what you know about the structure and function of a plasma membrane, Explain why a molecule like
glucose (even in a greater concentration outside the cell compared to inside the cell) cannot cross the
phospholipid bilayer of the plasma membrane and instead must travel through a protein "gate."
Glucose is a simple sugar used as an energy source. A chemist would describe glucose as being an
aldohexose and a monosacaccharide as well as being either linear or cyclic formed. A molecule like
glucose cannot cross the phospholipid bilayer of the plasma membrane and instead needs to travel
through a "gate" because they are too big to diffuse through the plasma membrane.
Explain the concept of osmosis. We know that the process of pickling, adding large amounts of salt,
causes changes in the food itself. A cucumber will shrink into a pickle. But how does adding large
amounts of salt affect microbes that may have contaminated the jar of pickles?
What does the salt do to the spoilage (bad) bacteria?
Osmosis is diffusion of water. Water will move from an area of high water concentration to an area of
low water concentration. Another way to look at it would be to say that water follows solute. If you have
two solutions and one has a high concentration of solute then it also has a low concentration of water. If
the second solution has a low concentration of solute then it has a high concentration of water. If water
were able to move between these two solutions (but solute was not) then water would travel from the
solution with a higher concentration of water to the solution with a lower concentration of water.
Microbes are everywhere and by growing on, consuming, and producing waste products, they spoil our
food. We can slow this process down by heating food up to boiling temperatures to kill all microbes
present and by refrigerating our food to cool enough temperatures that microbial metabolism and
microbial growth slows.
