Microbiology Chapter 4

Which of the following bacterial structures is necessary for chemotaxis? a. capsules b. flagella c. plasmids d. metachromatic granules

b. flagella

A __________ solution is a medium in which the overall concentration of solutes equals that found inside the cell. Water enters and leaves the cell at the same rate. a. hypertonic b. isotonic c. hypotonic d. ionic

b. isotonic

The plasma membrane is considered a barrier to the environment because __________. a. no molecules may pass through it b. it controls the passage of molecules into the cell c. it is located outside of the cell wall d. only water and small molecules may penetrate the membrane e. it contains rigid cellulose and steroid molecules

b. it controls the passage of molecules into the cell

Cocci may be arranged as __________. a. tetrads b. streptococci c. diplococcic d. staphylococci e. All of the listed answers.

e. All of the listed answers.

The Nucleus: * double membrane structure (___________) that contains the cell's DNA. * DNA is complexed with _______ proteins to form _________. * during mitosis and meiosis, chromatin condenses into ________.

* (nuclear envelope) * histone/ chromatin * chromosomes

Fimbriae and Pili: - Fimbriae: * hairlike appendages that allow for ________. * ________ than pili. - Pili: * involved in _____ (______ and _______ motions) * ________ involved in DNA transfer from one cell to another.

* attachment * shorter * motility (gliding and twitching) * conjugation pili

Comparing Prokaryotic and Eukaryotic Cells: - Prokaryote: * one _______ chromosome, not in a _________. * no ______ or _______. * include _____ and ______. * bacteria: _______ cells walls * archaea: ______ cell walls * divides by ________. - Eukaryote: * _______ chromosomes, in __________. * has _______ and _______. * ________ cell walls, when present. * divides by _______ for what three things?

* circular/ membrane * histones or organelles * bacteria and archaea * peptidoglycan * pseudomurein * binary fission * paired linear/ nuclear membrane * histones and organelles * polysaccharide * mitosis/ growth, repair, and replace

Composition and Characteristics: - Peptidoglycan: * polymer of a repeating ______ in rows: _____ and ______. * rows are linked by _______.

* disaccharide/ NAG and NAM * polypeptides

Atypical Cell Walls: - Acid-fast cell walls: * like _________ cell walls * include _____ and ______ * stain with _________ * _______ (______) bound to peptidoglycan = this interferes with gram staining! - Myoplasmas: * lack _______ (need a controlled environment because it is susceptible to _____________) * ______ in plasma membrane - Archaea: * ______ or * walls of _______ (lack NAM and D-amino acids).

* gram-positive * mycobacterium and nocardia * carbolfuchsin * waxy lipid (mycolic acid) * cell walls/ (osmotic pressure changes) * sterols * wallless * pseudomurein

Gram-Positive Cell Walls: - Teichoic acids: * _______ links cell wall to plasma membrane. * wall ________ links the peptidoglycan. * carry a _______ charge (due to acid) * regulate movements of ______. - _______ and ________ provide antigenic specificity. - What gives gram-positive bacteria strength and rigidity? - What does penicillin target in gram-positive bacteria?

* lipoteichoic acid * teichoic acid * negative * cations - polysaccharides and teichoic acids - carbohydrate backbone - the enzyme that forms the bond between protein and carbohydrate cross-linkage.

The Plasma (cytoplasmic) Membrane: - Compare and contrast prokaryotic and eukaryotic plasma membranes: * Similar in structure to prokaryotic cell membranes include: ________ and ________. * Differences in structure: ______ - complex lipids and ________ for attachment and cell-to-cell recognition. *Similar functions include: __________ and all _______/_______ processes. * Differences in function: - __________: phagocytosis and pinocytosis. - __________: pseudopods extend and engulf particles. - __________: membrane folds inward, bringing in fluid and dissolved substances.

* phospholipid bilayer and internal/peripheral proteins * sterols/ carbohydrates * selective permeability and passive/active * endocytosis/ phagocytosis/ pinocytosis

The Cell Wall and Glycocalyx: - Cell Wall: * found in _______ (3) * made of ________ (_____ in plants, _______ in fungi, and ________ in yeasts). - Glycocalyx: * found in _______ * _________ bonded to ________ and _______ in the plasma membrane.

* plants, algae, and fungi * carbohydrates (cellulose/ chitin/ glucan and mannan) * animal cells * carbohydrates/ proteins and lipids

- Gram-Positive Cell Walls: * _______ peptidoglycan (___________) * ________ acids * _____ in basal body of flagella. * produce _______. * _____ susceptibility to penicillin * disrupted by ________. - Gram-Negative Cell Walls: * ______ peptidoglycan * ______ membrane (main difference) * _________ space * _______ in basal body of flagella * produce ______ and ______. * _____ susceptibility to penicillin. - _____% of bacteria fall into one of these groups.

* thick (outer layer) * teichoic * 2-rings * exotoxins * high * lysozyme * thin * outer * periplasmic * 4-rings * endotoxins and exotoxins * low - 99

Plasma Membrane Structure: - Fluid Mosaic Model: * membrane is as _________ as olive oil. * semipermeable and ________ (______ have a hard time passing) * _____ move freely for various functions. * _______ rotate and move laterally. * self-sealing and self-healing * surprisingly _________. * proteins receive ________ from the world outside or transport ________ and ________.

* viscous * selective/ (charged ions) * proteins * phospholipids * flexible (supple) * signal/ nutrients and wastes

Evolution of Eukaryotes: - Life arose as simple organisms _____ to _____ billion years ago. - First eukaryotes evolved _____ billion years ago. - Endosymbiotic Theory: * larger bacterial cells engulfed smaller bacterial cells, developing the first ___________. * ingested photosynthetic bacteria became ________. * ingested aerobic bacteria become _________.

- 3.5 to 4 - 2.5 * eukaryotes * chloroplasts * mitochondria

Active Processes: - __________: requires a transporter protein and ATP; goes against gradient. - _________; requires a transporter protein and phosphoenolpyruvic acid (PEP); substance is altered as it crosses the membrane.

- active transport - group translocation

Shapes of Bacteria: - Include? * rod-shaped = * spherical = * spiral = * what differentiates spirillum from spirochete? - Most bacteria are spherical because it requires the _________ to maintain the shape.

- bacillus, coccus, spiral, star-shaped, or rectangular * bacillus * coccus * vibrio, spirillum, and spirochete * spirochetes have an endoflagella - least amount of energy

Glycocalyx: - External to the ______. - ______ and gelatinous. - Made of _______ and/or ______. - Two types: * ______: neatly organized and firmly attached. * _____: unorganized and loose. - Contribute to __________: * capsules prevent _________. * extracellular polymeric substance helps form ______.

- cell wall (peptidoglycan) - viscous - polysaccharide/ polypeptide * capsule * slime layer - virulence * phagocytosis (hid from immune system) * biofilms

- What structures do all bacteria have? - What structures do only some bacteria have?

- cell wall, plasma membrane, cytoplasm, 70s ribosomes, nucleoid containing DNA - capsule, flagella, inclusions, plasmid, fimbriae

The Nucleoid: - Bacterial _________ (nucleoid): _____ thread of DNA that contains the cell's genetic information. - ________: extrachromosomal genetic elements; carry non-crucial genes that help with ________ and ________.

- chromosome/ circular, singular - plasmids/ antibiotic resistance and production of toxins

Cell Walls and the Gram Stain Mechanism: - ________ crystals form inside cell. - Gram-positive: * _______ dehydrates peptidoglycan * CV-I crystals ________. - Gram-negative: * alcohol dissolves _______ and leaves holes in ________. * CV-I _______; cells are colorless. * ______ added to stain cells. - What are the four steps of the staining process?

- crystal violet-iodine * alcohol * do not leave * outer membrane/ peptidoglycan * washes out * safranin - 1. crystal violet (basic purple dye) for 1 minute/ 2. mordant (iodine) = sticks dye to bacteria = 1 minute/ 3. decolorizer (alcohol) = seconds/ 4. counterstain (red safranin) = 1 minute.

- _________ substance inside the plasma membrane and outside the nucleus. - ________: fluid portion of cytoplasm - ________: made of microfilaments and intermediate filaments; give _______ and _______. - ________: movement of the cytoplasm throughout a cell.

- cytoplasm - cytosol - cytoskeleton/ shape and support - cytoplasmic streaming

Arrangement of Coccus Bacterial Cells: - Pairs: - Clusters: - Chains: - Groups of four: - Cube-like groups of eight:

- diplo- - staphylo- - strepto- - tetrads - sarcinae

Mitochondria: - ______ membrane. - Contain inner folds (________) and fluid (_______) - Involved in __________ (ATP production).

- double - (cristae)/ (matrix) - cellular respiration

Axial Filaments: - Also called _________. - Found in _________. - Anchored at one end of a cell. - Rotation causes cell to move like a _________ because it is wrapped around the actual bacteria.

- endoflagella - spirochetes - corkscrew

Passive Processes: - __________: solute combines with a transporter protein in the membrane. * transports _____ and _______ across a membrane with the concentration gradient. - _________; the movement of water across a selectively permeable membrane from an area of high water to an area of low water concentration. * through ______ layer/ ______ (water channels)

- facilitated diffusion * ions and larger molecules - osmosis * lipid/ aquaporins

Flagella: - _______ appendages external of the cell. - _______ bacteria. - Made of protein _______. - Movement is _______ driven. - Three parts: * ________: outermost region. * ________: attaches to the filament. * _______: consists of rod an pairs of rings; anchors flagellum to the cell wall and membrane. - Flagella allow bacteria to move toward or away from stimuli (________) - Flagella rotate to _____ or ______. - Flagella proteins are ________ and distinguish among _______ (e.g. Escherichia coli O157:H7) = (ie this is an ___________). - ________: foreign substances that cause the immune system to make antibodies.

- filamentous - propel - flagellin - ATP * filament * hook * basal body - (taxis) - run or tumble - H antigens/ serovars/ (antigenic flagella) - antigens

- __________: solute concentrations equal inside and outside of cell; water is at equilibrium. - _________: solute concentration is lower outside than inside the cell; water moves into cell, causing ___________. - _________: solute concentration is higher outside of cell than inside; water moves out of cell, causing _________. - ________: the pressure needed to stop the movement of water across the membrane. * what environment were meats placed in for preservation before refrigerators?

- isotonic solution - hypotonic solution/ osmotic lysis (cell bursts) - hypertonic solution/ plasmolysis (imploding/ cell wall stay intact) - osmotic pressure * hypertonic

Flagella and Cilia: - Projections used for _______ or moving substances along the cell surface. - ________: long projections; few in number - ________: short projections; numerous. - Both consist of _______ made of the protein _______. * microtubules are organized as _____ pairs in a ring, plus ______ microtubules in the center (______ array). - Allow flagella to move in a _______ manner.

- locomotion - flagella - cilia - microtubules/ tubulin * nine/ two/ (9+2) - wavelike

Organelles: - __________: vesicles formed in the Golgi complex/ contain digestive enzymes. - __________: cavities in the cell formed from the Golgi complex/ bring food into cells; provide shape and storage. - _________: oxidize fatty acids; destroy H2O2. - _________: networks of protein fibers and centrioles/ form the mitotic spindle; crucial role in cell division.

- lysosomes - vacuoles - peroxisomes - centrosomes

Damage to Cell Wall: - _______ hydrolyzes bonds in peptidoglycan (in tears, sweat, and saliva). - ______ inhibits peptide bridges in peptidoglycan - ________ is a wall-less gram-positive cell. - ________ is a wall-less gram-negative cell. * both other the previous ones are susceptible to ________. - ______ are wall-less cells that swell into irregular shapes.

- lysozyme - penicillin - protoplast - spheroplast * osmotic lysis - L forms

Inclusions: - ___________: phosphate reserves. - ___________ (3): energy reserves - ___________: RuBisCO enzyme for CO2 fixation during photosynthesis. - __________: protein-covered cylinders that maintain buoyancy. - __________: iron oxide inclusions; destroy H2O2 * doesn't constitute as a ________.

- metachromatic granules (volutin) - polysaccharide granules, lipid inclusions, and sulfur granules - carboxysomes - gas vacuoles - magnetosomes * organelle

Golgi Complex: - Transport ________. - Modifies _______ from the ER. - Transports modified proteins via _________ to the plasma membrane.

- organelle - proteins - secretory vesicles

The Cell Wall: - Prevents _______ and protects the cell membrane. - Made of ______ (in bacteria) - Contributes to ________.

- osmotic lysis - peptidoglycan - pathogenicity

The Movement of Materials Across Membranes: - __________: substances move from high concentration to low concentration; _______ expended (DIFFUSION). - _________: substances move from low concentration to high concentration; ______ expended.

- passive processes/ no energy - active processes/ energy

Gram-Negative Cell Walls: - _______ between the outer membrane and the plasma membrane contains peptidoglycan (______ layer). - Outer membrane made of _______, ________, and ________. - Protect from ______, ______, and _______. - Made of ____________ (is a strong antigen that causes ________). * _________ functions as antigens (antigenic LPS). * _______ is an endotoxin embedded in the top layer. - ________(proteins) form channels through membrane. - What happens if you destroy a single gram-negative bacteria into lots of pieces?

- periplasm/ (thin) - polysaccharides, lipoproteins, and phospholipids - phagocytes, complement, and antibiotics - lipopolysaccharide (LPS)/ (fever) * O polysaccharide * Lipid A - porins - antigenic storm = amplify immune response = shock (sepsis)

Flagella Types: - ___________; multiple flagella everywhere. - ___________; one flagella. - ___________; multiple flagella on polar end. - ___________; multiple flagella on both ends.

- peritrichous - monotrichous - lophotrichous - amphitrichous

The Plasma (cytoplasmic) Membrane: - __________ that encloses the cytoplasm. - ________ on the membrane surfaces. - ______ and ______ proteins penetrate the membrane. - These proteins are what the _________ looks for in order to identify the cells.

- phospholipid bilayer - peripheral proteins - integral and transmembrane - immune system

Chloroplasts: - Locations of __________. - Contain flattened membranes (________) that contain chlorophyll.

- photosynthesis - (thylakoids)

Cytoplasm: - The substance inside the _______. - Eighty percent ______ plus proteins, carbohydrates, lipids, and ions. - Rigidity: _________ for eukaryotes and _________ for prokaryotes.

- plasma membrane - water - cytoskeleton/ cell wall

- Prokaryote comes from the Greek words for ________. - Eukaryote comes from the Greek words for ________.

- prenucleus - true nucleus

Ribosomes: - Sites of ________. - Made of _____ and ribosomal ______. - Prokaryotes = _______ (____S + _____S) - Eukaryotes = _______ (____S + ______S) * sedimentation coefficients in ________ units. * why are the S units important?

- protein synthesis - protein/ RNA - 70S (50/ 30) - 80S (60/ 40) * Svedberg * doctors exploit the difference in S units in order to target cells with protein synthesis inhibitors.

Endospores: - _____ cells; produced when ________ are depleted. - Very _______ to desiccation (_________), heat, chemicals, and radiation and antibiotics. - Produced by _______ and _______ (both soil bacteria). - __________; endospore formation. - _________; endospore returns to vegetative state (growing and dividing = make new bacteria) - NOT a _____________; rather a tie capsule. - Can all bacteria make these? - Important in food production because ________ interfere with germination processes.

- resting/ nutrients - resistant/ (removal of water) - Bacillus and Clostridium - sporulation - germination - reproductive organ - no - nitrates

- __________: are the sites of protein synthesis. - 80S: * consists of the large ______ subunit and the small _______ subunit. * membrane bound: attached to _______. * free: in ________. - 70S; * in _______ and ________.

- ribosomes * 60S/ 40S * ER * cytoplasm * chloroplasts and mitochondria

Plasma Membrane Functions: - The plasma membrane's _________ allows the passage of some molecules, but not others. - Contains enzymes for _____ production. - Some membranes have photosynthetic pigments on foldings called __________. - Damage to the membrane by ______, _________, and _______ causes leakage of cell contents (disrupts its integrity). - The plasma membrane creates a barrier which makes ____________ = creates energy (DAM EXAMPLE). - Where do bacteria has ATPase (used to make ATP)?

- selective permeability - ATP - chromatophores - alcohols, quaternary ammonium (detergents), and polymyxin antibiotics - concentration gradients - on outer membrane

- __________: movement of a solute from an area of high concentration to an area of low concentration. * continues until molecules reach _________. * with this process, large (polar) ions can't move through, but what can diffuse through the membrane?

- simple diffusion * equilibrium * O2, CO2, and water

Arrangement of Bacillus Bacterial Cells: - Include: single bacillus, coccobacillus, diplobacillus, and streptobacillus. - What arrangement can bacillus bacteria not be? Why?

- staphylo-/ because they don't divide along their long axis

Endoplasmic Reticulum: - Folded ______ network: - _________: studded with ribosomes; sites of protein synthesis. - ________: no ribosomes; synthesizes cell membranes, fats, and hormones.

- transport - rough ER - smooth ER

Which of the following processes occurs in bacterial plasma membranes but NOT in eukaryotic plasma membranes? a. ATP synthesis b. Active transport c. Protein synthesis d. Facilitated diffusion e. RNA synthesis

a. ATP synthesis

Which of the following is true of bacteria that have atypical cell walls, such as those in the genus Mycoplasma? a. Bacteria with atypical cell walls are generally among the smallest bacteria that can reproduce outside a host cell. b. These atypical bacteria have the same plasma membrane typical of bacteria. c. These atypical bacteria usually stain gram-negative. d. Although small, these atypical bacteria cannot pass through most filters.

a. Bacteria with atypical cell walls are generally among the smallest bacteria that can reproduce outside a host cell.

Which of the following statements is true? a. Endospores are extremely durable structures that can survive high temperatures. b. Endospores allow a cell to attach to solid surfaces and to surfaces within the host. c. Endospores are reproductive structures. d. One bacterial cell produces many endospores.

a. Endospores are extremely durable structures that can survive high temperatures.

Which of the following statements about a gram-negative cell wall is FALSE? a. It contains teichoic acid. b. It includes a thin layer of peptidoglycan. c. It functions as an endotoxin. d. It maintains the shape of the cell.

a. It contains teichoic acid.

What will occur if a bacterial cell with a weakened or damaged cell wall is placed in pure water? a. The cell will swell and burst. b. The cell will remain the same size. c. The cell will shrink. d. The cell will form endospores. e. The cell will form a new cell wall.

a. The cell will swell and burst.

In a prokaryotic cell, all of the following are functions of either fimbriae or pili EXCEPT __________. a. protection from phagocytosis or determining the shape of the cell b. transfer of DNA c. formation of biofilms d. attachment to a surface

a. a. protection from phagocytosis or determining the shape of the cell

Which of the following processes requires cellular energy in the form of ATP? a. active transport b. simple diffusion c. osmosis d. facilitated diffusion

a. active transport

A scientist is using sterilized river water as a growth medium for her bacterial cultures. The nutrient availability is very low in this water, and no additional nutrients have been added. What type of membrane transport are the bacteria growing in this media most likely to be using to obtain nutrients? a. Pinocytosis b. Active transport c. Facilitated diffusion d. Simple diffusion e. Osmosis

b. Active transport

Which of the following is NOT characteristic of the glycocalyx found in bacteria? a. A structure that can be visualized by negative staining b. Creates a slimy, slippery coating that prevents bacteria form attaching to surfaces c. If firmly attached, contributes to bacterial virulence d. A viscous coating surrounding the cell made of polysaccharide, polypeptide, or both

b. Creates a slimy, slippery coating that prevents bacteria form attaching to surfaces

Which of the following is a likely outcome, based on the unique cell structure of members of the genus Mycoplasma? a. Mycoplasma species can release endotoxins when they lyse. b. Mycoplasma species have very flexible cells that can pass through bacteriologic filters. c. Mycoplasma species usually stain gram-positive. d. Mycoplasma species are susceptible to penicillin. e. Mycoplasma species are susceptible to disruption by lysozymes.

b. Mycoplasma species have very flexible cells that can pass through bacteriologic filters.

The nucleus of a eukaryotic cell differs from the nucleoid of a prokaryotic cell in all of the following ways EXCEPT which one? a. The eukaryotic nucleus contains nucleoli. There are no nucleoli in the prokaryotic nucleoid. b. The prokaryotic nucleoid contains DNA combined with histones. Histones are lacking in the eukaryotic nucleus. c. The eukaryotic nucleus is surrounded by a nuclear envelope. There is no envelope surrounding the prokaryotic nucleoid. d. The prokaryotic nucleoid usually contains a single circular chromosome, whereas the eukaryotic nucleus contains multiple linear chromosomes.

b. The prokaryotic nucleoid contains DNA combined with histones. Histones are lacking in the eukaryotic nucleus.

You have isolated a cell with a peptidoglycan cell wall. What other structure can you safely assume the cell has? a. a nucleus b. a plasma membrane c. a mitochondrion d. a chloroplast

b. a plasma membrane

A population of bacterial cells has been placed in a very nutrient-poor environment with extremely low concentrations of sugars and amino acids. Which kind of membrane transport becomes crucial in this environment? a. facilitated diffusion b. active transport c. pinocytosis d. osmosis e. simple diffusion

b. active transport

Which of the following organisms have eukaryotic cells that do NOT contain a cell wall? a. algae b. animals c. fungi d. plants

b. animals

Many pathogenic (disease-producing) bacteria produce a(n) __________ that protects them from phagocytosis by host cells. a. flagellum b. capsule c. pilus d. endospore

b. capsule

The __________ is a fluid structure that allows membrane proteins to move freely. a. glycocalyx b. cell membrane c. ribosome d. cell wall

b. cell membrane

Which of the following membrane transport mechanisms takes place in eukaryotic cells but NOT in prokaryotic cells? a. facilitated diffusion b. endocytosis c. osmosis d. active transport

b. endocytosis

Spirochetes and spirilla are both spiral-shaped bacteria. However, they differ in that spirochetes have __________ and spirilla do not. a. fimbriae b. endoflagella (axial filaments) c. peritrichous flagella d. N-acetylglucosamine

b. endoflagella (axial filaments)

Chemotaxis refers to the ability of microorganisms to __________. a. survive under adverse conditions b. move toward or away from chemical stimuli c. attach to solid surfaces d. move in a wavelike motion e. escape phagocytosis

b. move toward or away from chemical stimuli

Gram-negative cells contain a periplasmic space that is __________. a. the site of protein synthesis b. rich in degradative enzymes c. abundant in teichoic acid d. a site of endocytosis e. filled with lysozyme

b. rich in degradative enzymes

The endoplasmic reticulum that has ribosomes attached to its outer surface is referred to as __________. a. smooth ER b. rough ER c. wavy ER d. golgi

b. rough ER

Which of the following is NOT true of the gram-negative outer membrane? a. It is a part of the gram-negative cell wall. b. It contains lipopolysaccharide. c. It contains enzymes for energy synthesis. d. It has polysaccharide antigens that are useful in bacterial identification. e. It contains lipids also known as endotoxins.

c. It contains enzymes for energy synthesis.

Bacillus anthraciscauses the deadly disease anthrax. Organisms of the genus Bacillus may form endospores. This bacterium would be suitable for biological warfare because endospores __________. a. are multilayered structures b. are difficult to stain c. are resistant to high temperatures, UV light, and desiccation d. are centrally located within the bacterial cells e. contain a high concentration of toxic enzymes

c. are resistant to high temperatures, UV light, and desiccation

Which of the following is NOT a structure of prokaryotic cells? a. flagellum b. capsule c. chloroplast d. chromosome e. ribosome

c. chloroplast

Which of the following processes uses membrane proteins that act as channels or carriers allowing ions or large molecules to move across the plasma membrane without using energy? a. active transport b. osmosis c. facilitated diffusion d. simple diffusion

c. facilitated diffusion

A Gram stain of a wound reveals purple, spherical bacteria that divide and remain attached in grapelike clusters. These are referred to as __________. a. gram-positive streptococci b. gram-positive tetrads c. gram-positive staphylococci d. gram-negative spirochetes

c. gram-positive staphylococci

Polyphosphate (volutin), carboxysomes, and magnetosomes are examples of __________. a. chloroplasts b. capsules c. inclusion bodies d. fimbriae e. mesosomes

c. inclusion bodies

Within the cytoplasm of bacterial cells are reserve deposits where certain nutrients accumulate. These are called __________. a. vacuoles b. ribosomes c. inclusions d. lysosomes

c. inclusions

The term describing bacteria with flagella that are arranged as a tuft coming from one pole is __________. a. amphytrichous b. peritrichous c. lophotrichous d. monotrichous

c. lophotrichous

Which of the following pairs is matched correctly? a. L form—a wall-less bacterium created by the action of lysozyme; the plasma membrane remains intact, and the cell carries on metabolism b. Mycoplasma spp.—bacteria that spontaneously, or in response to penicillin or lysozyme, partially lose their cell walls and swell into irregularly shaped bacteria that divide and metabolize and may regain their cell wall c. spheroplast—gram-negative bacteria that are exposed to lysozyme but retain some of the outer membrane d. protoplast—a genus of bacteria that typically do not have cell walls

c. spheroplast—gram-negative bacteria that are exposed to lysozyme but retain some of the outer membrane

Spherical bacteria that divide and remain attached in chainlike patterns are called __________. a. staphylococci b. tetrads c. streptococci d. spirochetes

c. streptococci

All of the following are found in the cell walls of gram-negative bacteria EXCEPT __________. a. lipid A b. porins c. teichoic acid d. N-acetylglucosamine e. tetrapeptide chains

c. teichoic acid

The motility of bacteria with flagella occurs through a series of "runs" and __________. a. phototaxis b. chemotaxis c. tumbles d. turns

c. tumbles

Which of the following statements about ribosomes is FALSE? a. Eukaryotic ribosomes are larger (80S) than prokaryotic ribosomes (70S). b. Cells with a high rate of protein synthesis have large numbers of ribosomes. c. Antibiotics that interfere with protein synthesis harm prokaryotic ribosomes, but not eukaryotic ribosomes. d. Antibiotics that interfere with protein synthesis harm both prokaryotic and eukaryotic ribosomes.

d. Antibiotics that interfere with protein synthesis harm both prokaryotic and eukaryotic ribosomes.

Which one of the following pairs is correctly matched? a. lysosomes—secretion b. mitochondrion—cell division c. centrioles—cellular respiration d. Golgi complex—membrane formation and secretion of proteins

d. Golgi complex—membrane formation and secretion of proteins

Penicillin specifically interferes with peptidoglycan synthesis. Which of the following cells is most likely to be damaged by penicillin? a. Cells of archaea b. Yeast cells c. Human cells d. Gram-positive bacterial cells

d. Gram-positive bacterial cells

You are observing a Gram stain of rod-shaped microorganisms that are linked in a chain and stain purple. How would you describe these bacteria using the correct terminology for the cell shape and arrangement? a. Gram-positive tetrads b. Gram-negative staphylococci c. Gram-positive coccobacilli d. Gram-positive streptobacilli

d. Gram-positive streptobacilli

Which of the following is NOT a functionally analogous pair? a. Bacterial flagella; 9 + 2 flagella b. Peptidoglycan; cellulose c. 70s ribosomes; 80S ribosomes d. Pili; centrioles e. Circular bacterial chromosome; linear eukaryotic chromosomes

d. Pili; centrioles

Which of the following statements does NOT provide evidence for the endosymbiotic theory? a. The ribosomes contained within mitochondria and chloroplasts are very similar to prokaryotic ribosomes. b. Mitochondria and chloroplasts contain circular DNA, similar to the DNA in prokaryotes. c. The same antibiotics that inhibit protein synthesis in prokaryotes also inhibit protein synthesis within mitochondria and chloroplasts. d. Prokaryotes contain peptidoglycan in their cell walls.

d. Prokaryotes contain peptidoglycan in their cell walls.

The antibiotic polymyxin B combines with phospholipids. This will cause __________. a. stoppage of protein synthesis b. sporulation c. loss of motility d. leakage of intracellular contents e. binary fission

d. leakage of intracellular contents

The term describing bacteria with flagella distributed over the entire surface of the cell is __________. a. monotrichous b. amphytrichous c. lophotrichous d. peritrichous

d. peritrichous

A eukaryotic cell can ingest a prokaryotic cell by __________. a. pinocytosis b. digestive vacuolization c. active transport d. phagocytosis e. osmosis

d. phagocytosis

Consider a gram-positive cell in a hypertonic medium. If the peptidoglycan were damaged, the cell would __________. a. swell b. remain the same size c. shrink and then swell d. shrink

d. shrink

With a light microscope, which of the following would allow discrimination between eukaryotes and prokaryotes? a. Observation of the plasma membrane b. Observation of the ribosomes c. Observation of flagella d. Observation of photosynthetic pigment e. Observation of nuclei

e. Observation of nuclei

Why is penicillin selectively toxic to bacterial cells but harmless to human cells? a. Penicillin is rapidly metabolized and destroyed by human cells. b. The glycocalyx of an animal cell provides a barrier through which penicillin cannot pass. c. Human cells actively transport penicillin out of the cell. d. Penicillin is inactivated within lysosomes of human cells. e. Penicillin specifically weakens peptidoglycan, which is found only in bacterial cells.

e. Penicillin specifically weakens peptidoglycan, which is found only in bacterial cells.

Which of the following pairs is MISMATCHED? a. Endoplasmic reticulum; internal transport b. Golgi complex; secretion c. Mitochondria; ATP production d. Lysosome; digestive enzymes e. Ribosomes; storage

e. Ribosomes; storage

The nucleoid (nuclear area) of the bacterial cell __________. a. is enclosed in a nuclear membrane b. has abundant histone proteins c. contains many linear chromosomes d. is connected to the endoplasmic reticulum e. contains the bacterial chromosome

e. contains the bacterial chromosome

All of the following are found in the cell walls of gram-positive bacteria EXCEPT __________. a. peptidoglycan b. teichoic acid c. N-acetylglucosamine d. lipoteichoic acid e. lipid A

e. lipid A

Phototaxis refers to the ability of microorganisms to __________. a. move toward or away from chemical stimuli b. move in a wavelike motion c. attach to solid surfaces d. survive under adverse conditions e. move toward a source of light.

e. move toward a source of light.

Assume you are growing a bacterial culture in a glucose medium. Your lab partner adds more glucose in hopes of speeding up the experiment. The bacteria suddenly die. The best explanation for this result is that __________. a. glucose is toxic to bacteria b. the bacteria could not use glucose c. osmotic lysis occurred d. the cells underwent sporulation e. the cells plasmolyzed

e. the cells plasmolyzed