Ch. 2 Bacteria

What is the characteristic cellular organization of prokaryotes?

Long, double-stranded DNA

Bacterial chromosomes lack what?

Introns

What type of pathogens are a continuous coding sequence of genes?

bacteria

What type of pathogen has chromosomes that are not localized within a distinct nucleus, have no nuclear membrane, and are coiled into a region called a nucleoid?

Bacteria

What is a plasmid?

extrachromosomal DNA in a cell that is small, circular, and self-replicating

Bacteria only contains what type of organelles?

Ribosomes

What is the function of bacterial ribosomes?

protein synthesis

What are the subunits of the bacterial ribosome?

50S and 30S (makes up 70S ribosome)

What type of ribosomes do humans have?

80S

70S ribosomes are targeted by what?

antimicrobials

What structure carries out many of the metabolic functions of bacteria?

prokaryotic cell membrane

All bacteria are surrounded by what?

a complex cell wall

What is the exception of bacteria that lacks a cell wall?

mycoplasmas

What characteristics of bacteria are external to the cell wall?

Capsule, flagella, and pili

What is the main structural component of the cell wall?

peptidoglycan

What is peptidoglycan made of?

mixed polymer of hexose sugars and amino acids (N-acetylglucosamine (NAG) and N-acetylmuramic acid (NAM))

What type of bacteria have a thick peptidoglycan layer? Gram-positive or gram-negative?

gram-positive

What type of bacteria have a thin peptidoglycan layer? Gram-positive or gram-negative?

gram-negative

What structural component provides a thick hydrophilic surface?

peptidoglycan

What components make the peptidoglycan highly polar?

Polysaccharides and charged amino acids

What structural component allows for resistance to bile in the intestines?

peptidoglycan

Peptidoglycan can be digested by what?

lysozyme

Beta-lactams and glycopeptides can disrupt what structural component?

peptidoglycan

What component of gram-negative peptidoglycan gives it hydrophobic properties?

lipid

What component of gram-negative peptidoglycan allows for the entry for hydrophilic sugars and amino acids?

porins

What component of gram-negative peptidoglycan confers antigenic properties and toxic properties?

lipopolysaccharide (LPS)

What component of lipopolysaccharide (LPS) is antigenic?

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A. Lipid A component

B. O antigen from the carbohydrate chain

B. O antigen from the carbohydrate chain

What component of lipopolysaccharide (LPS) is toxic?

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A. Lipid A component

B. O antigen from the carbohydrate chain

A. Lipid A component

What type of bacteria is neither gram-negative or gram-positive?

mycobacteria

What type of bacteria possess an outer membrane with complex lipids?

A. Gram-negative

B. Gram-positive

C. Mycobacteria

C. Mycobacteria

What type of acid creates a waxy layer?

mycolic acid

What type of acid allows for resistance to drying and other environmental factors?

mycolic acids

What are the most common shapes of bacteria?

Cocci (spherical)

Bacilli (rods)

Spirilla (helical)

What bacterial virulence factor is made of high molecular weight polysaccharides such as amino acids, hyaluronic acid, etc.

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A. Capsule

B. Flagella

C. Pili

A. Capsule

What gives capsules their slimy surface?

polysaccharides

What do polysaccharide capsules provide protection against?

phagocytosis by host cells

What is an example of capsulated organisms that can cause a fatal disease while unencapsulated mutants are avirulent?

*Streptococcus pneumoniae*

What bacterial virulence factor is a long, helical filament that extends out from the surface to allow for movement in the environment-motility?

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A. Capsule

B. Flagella

C. Pili

B. Flagella

Bacteria with a single flagellum are considered what?

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A. Lophotrichous

B. Peritrichous

C. Polar

C. Polar

Bacteria with tufts of flagellum are considered what?

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A. Lophotrichous

B. Peritrichous

C. Polar

A. Lophotrichous

Bacteria with flagellum distributed all over the surface are considered what?

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A. Lophotrichous

B. Peritrichous

C. Polar

B. Peritrichous

The motility of flagella is driven by what?

by movement of hydrogens across the cell membrane

What bacterial virulence factor allows positive and negative responses to environmental stimuli?

A. Capsule

B. Flagella

C. Pili

B. Flagella

Chemotaxis

motility response to chemicals

What bacterial virulence factor is made of protein components that are strongly antigenic?

A. Capsule

B. Flagella

C. Pili

B. Flagella

What are the protein components that make up flagella?

flagellins and H antigens

What component of flagella serves as a target of protective antibody responses?

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A. Flagellins

B. H antigens

B. H antigens

What bacterial virulence factor is more rigid than flagella?

A. Capsule

B. Flagella

C. Pili (fimbriae)

C. Pili (fimbriae)

What bacterial virulence factor plays a large role in adherence to host cells?

A. Capsule

B. Flagella

C. Pili (fimbriae)

C. Pili (fimbriae)

The presence of what bacterial virulence factor may precent phagocytosis?

A. Capsule

B. Flagella

C. Pili (fimbriae)

C. Pili (fimbriae)

What bacterial virulence factor allows bacteria to avoid immune recognition and has antigenic variation?

A. Capsule

B. Flagella

C. Pili (fimbriae)

C. Pili (fimbriae)

How do bacteria obtain nutrients?

by taking up small molecules across the cell wall

What nutrients are taken up across the cell wall by bacteria?

amino acids, oligosaccharides, small peptides

What type of bacteria can take up larger molecules after preliminary digestion in the periplasmic space? Gram-negative or gram-positive?

Gram-negative

What allows for the uptake and transport of nutrients into the cytoplasm?

transport mechanisms

What type of transport is passive? Facilitated diffusion or active transport?

Facilitated diffusion

What type of transport requires energy? Facilitated diffusion or active transport?

active transport

What type of metabolism takes place at the membrane-cytoplasm interface?

oxidative metabolism

What are the only type of nutrients required for *E. coli?*

glucose and inorganic salt

What type of nutrients do *Streptococcus* species need?

sugars, salts, and organic compounds

How do all bacteria obtain energy?

by oxidizing preformed organic molecules (carbohydrates, lipids, proteins)

What is the energy source of bacteria?

ATP

What are the two different types of metabolism?

aerobic and anaerobic

What is the final electron acceptor in aerobic metabolism?

oxygen

What is the final electron acceptor in anaerobic metabolism?

may be an organic or inorganic molecule other than oxygen

All pathogenic bacteria are what?

heterotrophic

What type of metabolism is the complete utilization of an energy source such as glucose?

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A. Aerobic metabolism

B. Anaerobic metabolism

A. Aerobic metabolism

What type of metabolism produces 38 molecules of ATP?

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A. Aerobic metabolism

B. Anaerobic metabolism

A. Aerobic metabolism

Obligate

absolutely required

Facultative

may need it, may not

What type of metabolism utilizes an inorganic molecule other than oxygen as the final hydrogen acceptor?

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A. Aerobic metabolism

B. Anaerobic metabolism

B. Anaerobic metabolism

What type of metabolism is considered an incomplete mechanism?

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A. Aerobic metabolism

B. Anaerobic metabolism

B. Anaerobic metabolism

What type of metabolism can be used in the absence of oxygen when the appropriate substrates are available?

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A. Aerobic metabolism

B. Anaerobic metabolism

B. Anaerobic metabolism

What type of metabolism produces fewer ATP?

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A. Aerobic metabolism

B. Anaerobic metabolism

B. Anaerobic metabolism

What is a type of anaerobic metabolism that utilizes an organic final hydrogen acceptor and is much less efficient?

fermentation

Fermentation only produces how many molecules of ATP?

2 molecules of ATP

What does fermentation used to generate additional energy?

pyruvate

What foods are commonly made using fermentation methods?

Kefir, Kombucha, Miso, Kimchi, Sauerkraut, Yogurt

The ability of bacterial to grow in what correlates to enzymatic ability to deal with destructive ROS?

the ability to grow in oxygen

What type of bacteria absolutely requires oxygen?

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A. Aerotolerant anaerobes

B. Facultative anaerobes

C. Microaerophiles

D. Obligate aerobes

E. Obligate anaerobes

D. Obligate aerobes

What type of bacteria absolutely does NOT want oxygen?

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A. Aerotolerant anaerobes

B. Facultative anaerobes

C. Microaerophiles

D. Obligate aerobes

E. Obligate anaerobes

E. Obligate anaerobes

What type of bacteria only requires a little bit of oxygen oxygen?

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A. Aerotolerant anaerobes

B. Facultative anaerobes

C. Microaerophiles

D. Obligate aerobes

E. Obligate anaerobes

C. Microaerophiles

What type of bacteria is does not like oxygen but can tolerate it?

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A. Aerotolerant anaerobes

B. Facultative anaerobes

C. Microaerophiles

D. Obligate aerobes

E. Obligate anaerobes

A. Aerotolerant anaerobes

What type of bacteria will use oxygen if it is present, but is also capable of switching to fermentation if oxygen is absent?

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A. Aerotolerant anaerobes

B. Facultative anaerobes

C. Microaerophiles

D. Obligate aerobes

E. Obligate anaerobes

B. Facultative anaerobes

What factor of bacteria depends on the nutritional status of the environment

The growth rate

How often does *E. coli* replicate?

every 20-30 minutes

How often does *M. tuberculosis* replicate?

every 24 hours

What is the characteristic pattern of bacterial growth?

Lag phase → Logarithmic phase → Stationary phase → Death

The following is characteristic of what phase of bacterial growth?

* Initial period of adjustment where bacteria are sensing their environment.

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A. Death

B. Lag Phase

C. Log Phase

D. Stationary Phase

B. Lag Phase

The following is characteristic of what phase of bacterial growth?

* Cell division occurs rapidly
* Doubling of population
* Can calculate doubling time

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A. Death

B. Lag Phase

C. Log Phase

D. Stationary Phase

C. Log Phase

The following is characteristic of what phase of bacterial growth?

* Cell growth slows to a stop.

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A. Death

B. Lag Phase

C. Log Phase

D. Stationary Phase

D. Stationary Phase

The following is characteristic of what phase of bacterial growth?

* Decline in population.

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A. Death

B. Lag Phase

C. Log Phase

D. Stationary Phase

A. Death

Before bacteria can undergo cell division, what must bacteria do?

Bacteria must replicate genomic DNA

Where does genomic replication begin in bacteria?

at the origin of replication (OriC)

What happens when the multienzyme replication complex binds to the OriC during bacterial replication?

It initiates unwinding and separation of the 2 DNA strands through helices and topoisomerase

During bacterial DNA replication, DNA polymerase incorporates what?

deoxyribonucleotides

What enzyme proofreads the new deoxyribonucleotides?

DNA polymerase

Bacterial cell division is preceded by what?

segregation and septum formation

Where does the formation of the septum occur?

in the middle of the cell

Which of the following stages in bacterial cell division are not tightly coupled?

Septum formation, DNA replication, and genome segregation