Microbiology Chapter 3 Assignment

What characterizes a capsule?

-not easily removed -well organized -helps resist phagocytosis

steps in the bacterial method of iron uptake for the cell

1) Iron scarce in environment 2) Bacteria secretes siderophore 3) Iron-siderophore complex binds cell surface protein 4) Iron-siderophore complex enters cell via ABC transporter

function of gas vesicle

Contains compounds that aid in buoyancy

function of chromosome

Contains genetic information required for survival

function of storage granules

Contains high-molecular weight polymers

Bacteria contain several types of cytoskeletal proteins. Match the protein with its function within the cell: Bactofilin

Protein and chromosome positioning

Match the following bacterial external structures with their correct function to review bacterial appendages: fimbriae

Responsible for bacterial attachment to surfaces

Match the following bacterial external structures with their correct function to review bacterial appendages: flagellum

Responsible for locomotion

Bacterial endospores are protected from chemicals and various lytic enzymes due to the presence of the spore layer called the _________.

coat

The movement of dissolved solutes from a region of higher concentration to a region of lower concentration is called _________.

diffusion

The addition of alcohol during the Gram-staining procedure causes decolorization of Gram-negative bacteria and the addition of safranin results in ______ cells.

pink

The cell wall of Gram-negative bacterial cells is external to the _______ .

plasma membrane

Inclusions containing carbon are most commonly in the form of ______ and can be commercially used to create biodegradable plastics.

poly-beta-hydroxybutyrate

Characteristics of peripheral proteins

-30% of membrane proteins -easily extracted -soluble in aqueous solution -loosely connected to cell membrane

Characteristics of integral proteins

-70% of membrane proteins -not easily extracted -insoluble in aqueous solutions -embedded in cell membrane

Before the understanding of bacteria and archaea as distinct domains, certain characteristics were used to define prokaryotes. Select the cell components that were believed to be lacking before genetic and genomic analyses proved otherwise. -A membrane-bound nucleus -A cytoskeleton -A Golgi apparatus -An endoplasmic reticulum -A plasma membrane -Ribosomes

-A cytoskeleton -A Golgi apparatus -A plasma membrane

Select the true statements with respect to the use of the term "prokaryote." -Bacteria have an endoplasmic reticulum but archaea do not. -Both bacteria and archaea have cytoskeletal components -Archaea have a Golgi apparatus but bacteria do not. -It is preferable to define an organism by what it contains, rather than what it lacks. -Bacteria and archaea are genetically distinct from each other.

-Both bacteria and archaea have cytoskeletal components -It is preferable to define an organism by what it contains, rather than what it lacks. -Bacteria and archaea are genetically distinct from each other.

Review the properties of endospores that allow them to survive adverse environmental conditions by selecting protective properties of the endospore core below. -Core has low amounts of dipicolinic acid complexed with calcium ions -Core has a slightly basic pH -Core has a slightly acidic pH -Core has low water content -Core has high water content -Core has high amounts of dipicolinic acid complexed with calcium ions

-Core has a slightly acidic pH -Core has low water content -Core has high amounts of dipicolinic acid complexed with calcium ions

Macroelements are required in relatively large amounts by the cell. Select all of the characteristics of macroelements to review their importance to the cell. -Examples are oxygen, hydrogen, carbon -Required in relatively small amounts by the cell -Only found in inorganic molecules -Some exist as cations -Some exist as anions -Can contribute to molecule stability

-Examples are oxygen, hydrogen, carbon -Some exist as cations -Can contribute to molecule stability

Select the statements below that correctly apply to characteristics of bacterial cell permeability. -Is a barrier to passive diffusion of large compounds -Is a barrier to water -Can take up insoluble molecules -Has presence of aquaporins

-Is a barrier to passive diffusion of large compounds -Has presence of aquaporins

Nearly all bacteria contain peptidoglycan. Review the structure of peptidoglycan by selecting the correct characteristics listed below. -Polymer of alternating N-acetylglucosamine (NAG) and N-acetylmuramic acid (NAM) -Contains a tetrapeptide that extends from N-acetylglucosamine (NAG) -Contains D-amino acids not found in proteins -All bacteria use a peptide interbridge to connect the sugar strands -Peptidoglycan is a strong and rigid structure

-Polymer of alternating N-acetylglucosamine (NAG) and N-acetylmuramic acid (NAM) -Contains D-amino acids not found in proteins

Gliding motility in bacteria involves which of the following? -Specialized cell-surface proteins and slimy polysaccharides -Flagella -Specialized cell-surface proteins -Specialized cell-surface proteins, flagella, and slimy polysaccharides -Slimy polysaccharides

-Specialized cell-surface proteins and slimy polysaccharides

The rate of diffusion of a molecule into a cell is affected by which of the following factors? -Same concentration of a molecule outside the cell as inside the cell -Lower concentration of a molecule outside of the cell -Steep concentration gradient with a high amount of the molecule outside the cell -Steep concentration gradient with a high amount of the molecule inside the cell

-Steep concentration gradient with a high amount of the molecule outside the cell

Which of the following statements is FALSE when comparing bacterial and eukaryotic cytoskeletal proteins? -There are homologues of both microtubules and actin filaments found in bacterial cells. -The cytoskeletal proteins found in bacterial cells are structurally and functionally unrelated to those found in eukaryotic cells. -Similarities between the bacterial and eukaryotic cytoskeleton suggest these proteins evolved early in the formation of life on earth. -Like the eukaryotic cytoskeleton, bacterial cytoskeletal proteins function in cell division, protein positioning, and determination of cell shape.

-The cytoskeletal proteins found in bacterial cells are structurally and functionally unrelated to those found in eukaryotic cells.

Which statement about flagellar structure is TRUE? -The filament extends out of the cell. -The hook anchors the flagellum in the cell membrane, the basal body is a short curved segment, and the filament extends out of the cell. -The basal body is a short curved segment. -The hook anchors the flagellum in the cell membrane and the filament extends out of the cell. -The hook anchors the flagellum in the cell membrane.

-The filament extends out of the cell.

The bacterial flagellum moves _________. -by rotation that is powered by the proton motive force -in a wave-like fashion that is powered by the proton motive force -in either a wave-like fashion or rotation that is powered by the proton motive force -by rotation that is powered by ATP -in a wave-like fashion that is powered by ATP

-by rotation that is powered by the proton motive force

Evaluate the statements below and choose those that would constitute growth factors in bacterial cells. -lactose -cysteine -starch -adenine -thymine -nicotinic acid -folic acid -phospholipids

-cysteine -adenine -thymine -nicotinic acid -folic acid

What characterizes a slime layer?

-facilitates motility -diffuse (unorganized) -easily removed

The number of proteins associated with the bacterial ribosome is well characterized; there are approximately 55 proteins total— _____ in the small subunit and _____ in the large.

21, 34

The bacterial ribosome is smaller than those found in eukaryotes. It is designated as a ______ .

70s ribosome

function of endospore

A dormant cell state

Why is boiling at standard temperature and pressure an inadequate method of processing for canned foods?

Boiling to 100°C will kill vegetative C. botulinum cells, but any spores will survive to temperatures of 120°C.

Bacteria contain several types of cytoskeletal proteins. Match the protein with its function within the cell: FtsZ

Cell division

Monotrichous

One flagellum extends from the cell to power locomotion.

function of plasmids

Extrachromosomal DNA molecules

True or false: Germination is one process by which bacterial cells can reproduce.

False

True or false: Gram-positive bacteria have flagella with four basal body rings, while those of Gram-negative bacteria have only two.

False

True or false: In an endospore, the protein coat forms a layer external to the exosporium.

False

True or false: Most substances are able to undergo passive diffusion across the plasma membrane in order to enter a cell. Group starts

False

Which of the following bacterial structures are most directly linked to swimming motility in chemotaxis? -Flagella -Capsule -Fimbriae -Pili

Flagella

Peritrichous

Flagella spread over the entire surface of the bacteria to power locomotion.

Gram-positive or Gram-negative?: Final Gram stain color - Pink

Gram-Negative Bacteria

Gram-positive or Gram-negative?: Lipopolysaccharide - LPS present

Gram-Negative Bacteria

Gram-positive or Gram-negative?: Outer membrane - Outer membrane present

Gram-Negative Bacteria

Gram-positive or Gram-negative?: Relative thickness of peptidoglycan - Thin peptidoglycan

Gram-Negative Bacteria

Gram-positive or Gram-negative?: Sensitivity to lysozyme - Not sensitive to lysozyme

Gram-Negative Bacteria

Gram-positive or Gram-negative?: Sensitivity to penicillin - Less sensitive to penicillin

Gram-Negative Bacteria

Gram-positive or Gram-negative?: Teichoic acids - Teichoic acids absent

Gram-Negative Bacteria

Gram-positive or Gram-negative?: Final Gram stain color - Purple

Gram-Positive Bacteria

Gram-positive or Gram-negative?: Lipopolysaccharide - LPS absent

Gram-Positive Bacteria

Gram-positive or Gram-negative?: Outer membrane - Outer membrane absent

Gram-Positive Bacteria

Gram-positive or Gram-negative?: Relative thickness of peptidoglycan - Thick peptidoglycan

Gram-Positive Bacteria

Gram-positive or Gram-negative?: Sensitivity to lysozyme - Sensitive to lysozyme

Gram-Positive Bacteria

Gram-positive or Gram-negative?: Sensitivity to penicillin - More sensitive to penicillin

Gram-Positive Bacteria

Gram-positive or Gram-negative?: Teichoic acids - Teichoic acids present

Gram-Positive Bacteria

Bacteria contain several types of cytoskeletal proteins. Match the protein with its function within the cell: MreB

Helps determine shape of cell

function of cytoskeleton

Involved in cell division and controlling cell shape

function of ribosome

Involved in protein synthesis

Which of the following is a component of the outer membrane in Gram-negative bacteria that results in septic shock upon entering the bloodstream?

Lipopolysaccharide

definition of simple diffusion

Movement of molecules from areas of higher concentration to areas of lower concentration

When analyzing the outer membrane of Gram-negative bacteria, which part of lipopolysaccharide induces an antibody response?

O antigen

Match the following bacterial external structures with their correct function to review bacterial appendages: sex pilus

Responsible for transferring DNA from one bacterial cell to another

Bacteria contain several types of cytoskeletal proteins. Match the protein with its function within the cell: ParA

Segregates chromosomes and plasmids

Lopotrichous

Several flagella extending from one cell "pole" to power locomotion.

True or false: Complete bacterial ribosomes are comprised of approximately 55 proteins and three molecules of ribosomal RNA.

True

True or false: Spirochetes move in a screw-like manner that is mediated by bundles of flagella located in the cell's periplasmic space.

True

True or false: Spore formation is initiated when there is a scarcity of nutrients.

True

Amphitrichous

Two flagella extend from two different cell "poles" to power locomotion.

When observing flagella distribution patterns, bacteria with a single flagellum at each pole are called _________ bacteria.

amphitrichous

Another type of inclusion, which photosynthetic microbes often use to store carbon dioxide and the enzyme RuBisCO, is the _______ .

carboxysome

Match the major types of bacterial plasmids to the correct function: R plasmids

carry antibiotic resistance genes

Match the major types of bacterial plasmids to the correct function: Metabolic plasmids

carry genes for enzymes

Match the major types of bacterial plasmids to the correct function: Virulence plasmids

carry virulence genes

To review the transformation of an endospore into a vegetative cell, match the stages of germination with their properties: Outgrowth

core enzymes become active due to increased water levels

The spore layer containing peptidoglycan is the _________.

cortex

Nucleoid-associated proteins bind to the DNA via _____ that cause the DNA to bend and fold

covalent bonds

Clostridium botulinum, which produces a toxin that causes botulism, is a major concern of the food industry due to its production of an extremely heat-resistant _________.

endospore

When discussing a ribosome's size, the "s" stands for Svedberg unit; a measure of how fast a particle travels when centrifuged. The greater the number, the ______ it travels.

faster

Finally, buoyancy in aquatic bacteria is mediated by ________ , while certain bacteria accumulate magnetite in _______ that can detect natural magnetic fields.

gas vacuoles, magnetosomes

To review the transformation of an endospore into a vegetative cell, match the stages of germination with their properties: Germination

germinant receptor proteins detect sugars or amino acids

Capsules and slime layers are networks of polysaccharides that can extend from the bacterial surface. Both capsules and slime layers can be encompassed by the general term _________.

glycocalyx

A rod with the same S/V ratio as a cocci can have ________ uptake across its cytoplasmic membrane than the cocci.

greater nutrient

Some molecules needed for survival cannot be synthesized by the cell but instead must be obtained from the environment. These types of molecules include vitamins and amino acids and are collectively called ______ ______.

growth factors

To review the transformation of an endospore into a vegetative cell, match the stages of germination with their properties: Activation

heat treatment prepares spores for germination

Epulopiscium fishelsoni has a highly convoluted plasma membrane to ______ its S/V ratio to compensate for its large size.

increase

Nutrient uptake and diffusion of molecules into the bacterial cell become more efficient as the surface area-to-volume ratio _________.

increases

Bacterial movement toward or away from a chemical is often described as a "random biased walk" due to the fact that _________.

it still tumbles to change direction but it occurs less often than in the absence of a chemical, and runs more, creating an overall net motion in one direction

Bacterial chromosomes are _____ than the cell, so the genetic material must be _____ packaged.

longer, tightly

A cocci with the same volume as a rod has a ______ S/V ratio than does the rod.

lower

The plasma membrane must possess mechanisms for getting nutrients into the cell. Nutrients such as oxygen and hydrogen are needed in relatively large amounts and are referred to as ________.

macroelements

In bacteria, as the surface area-to-volume ratio increases, nutrient uptake becomes _______ .

more efficient

In endospore formation, when DNA condenses and aligns itself in the center of the cell, the cell is called a(n) ________.

mother cell

In addition, there is a(n) ______ external to the Gram-negative bacterial peptidoglycan layer.

outer membrane

The germination process of an endospore into a vegetative cell involves core enzymes becoming active due to increased water levels resulting in the ________ stage.

outgrowth

In the Gram-positive bacterial cell wall, the tetrapeptides that extend from the peptidoglycan layers are linked by _________.

peptide interbridges

This structure contains only a thin layer of ______ .

peptidoglycan

The two-layer cell wall of Gram-negative bacteria is separated from the plasma membrane by the ________ .

periplasmic space

Nucleic acids are synthesized from inorganic inclusions called _______ , while specialized photosynthetic bacteria can store energy as ________

polyphosphate granules, sulfur globules

Match the major types of bacterial plasmids to the correct function: Col plasmids

produce bacteriocins

The bacterial flagellum is driven to rotate by protons moving down a charge and pH gradient and the energy provided is called the _________ _________ _________.

proton motive force

During binary fission, DNA binding proteins play an important role in compacting the daughter chromosomes to ensure proper _______ as the cell divides.

replication

Many bacteria have overcome the difficulty of iron uptake by secreting low molecular weight iron-binding proteins called _________.

siderophores

The chromosome has several levels of structural organization, including macrodomains, chromosome interaction domains, and ________

supercoiling

Match the major types of bacterial plasmids to the correct function: conjugative plasmids

transfer DNA from one cell to another

Bacterial cells contain thousands of ribosomes that carry out ______ . Some are located in the cytoplasm and others are attached to the ______ .

translation, plasma membrane