Past Exam 2

(Internal structures) Which of the following has been observed in the cytoplasm of some bacterial cells?

(All yes) A. Membrane bound compartments B. DNA within an intracellular membrane C. All three types of cytoskeleton D. DNA wrapped around proteins E. Aggregates of protein or glycogen F. Clumps of iron and sulfur

29. -Describe how the penicillin family members of antibiotics act against bacteria. -Describe their mechanism of action (what they target or act against) -and what effect the antibiotic has on bacterial cells. (4 pts)

- Penicillin family members inhibit the synthesis of new peptidoglycan. - Penicillin structurally are similar to the Ala-Ala in the peptide of peptidoglycan and inhibits the action of transpeptidase enzyme and maybe the transglycoslyation enzyme found in penicillin binding proteins. - The inhibition of peptidoglycan synthesis will ultimately lead to holes in the peptidoglycan layer which will usually result in the lysis of the cell when the membrane expands to far

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32. What are two roles of the cell wall in bacteria? (3 pts)

-Structural support -Help determine cell shape -Prevents cell lysis in hypotonic conditions by preventing the membrane from expanding too far -Block entry or reduce diffusion of some types of molecules -Provide protection.

29. List 3 ways that the composition of cell walls differs between different kinds of bacteria? (6 pts)

1. Almost all true bacteria have a cell wall composed of Peptidoglycan but Archaea cell wall if present is composed of pseudopeptidoglycan which differs by one sugar 2. The cell wall can vary in thickness, Gram positive bacteria have a thicker cell wall layer than Gram negative bacteria 3. The peptide cross bridge varys. It varys most at the 3 amino acid position 4. Some Gram positive have an additional chain of Gly in the peptide cross link 5. The cell wall of Mycobacteria also contain the waxy lipid mycolic acid

28. Describe the layer and components found in the envelope of a Gram positive bacteria. (4 pts)

1. May have a capsule composed of sugars and/or protein or some type of sugar layer 2. May have a S-layer composed of protein 3. Has a thick layer of peptidoglycan and teichoic acid 4. Cell membrane composed of phospholipids and proteins

18. Terpene isoprenoids are found in the _______ A. Cell membrane of archaeal bacteria B. Outer membrane of Gram negative bacteria C. Cell wall of acid fast Mycobacterium D. Cell wall of Gram positive bacteria E. Cell membrane of Mycoplasma

A. Cell membrane of archaeal bacteria

13. Which of the following list the layers in the envelope found in the mollicute bacteria of the genus Mycoplasma? A. Cell membrane with some sugars on its outside B. Peptidoglycan and teichoic acid and cell membrane C. Mycolic acid, arabinan-galactan sugar layer, peptidoglycan and cell membrane D. Pseudopeptidoglycan and S layer and cell membrane E. Outer membrane with lipopolysaccharide, Peptidoglycan and cell membrane

A. Cell membrane with some sugars on its outside

18. Which of the following has the same mechanism of action as penicillin? A. Cephalosporins B. Bacitracin C. D-cycloserine D. Lysozyme E. Mycolic Acid

A. Cephalosporins

8. Which of the following is NOT a function of the glycocalyx or capsule? A. Determining cell shape B. Attachment of bacteria to surfaces C. Protection from desiccation D. Protection from phagocytosis E. Formation of biofilms

A. Determining cell shape

8. What is different about motility observed in spirochete bacteria from the typical flagellated bacteria? A. Mediated by flagella but the flagella are located in the periplasm and wrap around the cell from each end B. Mediated by pili attaching and contracting C. Movement based on sliding across a capsule or slime layer D. Make little feet like projections that move to help the cell walk along a surface E. The flagella do not rotate but instead wave back and forth

A. Mediated by flagella but the flagella are located in the periplasm and wrap around the cell from each end

16. Which of the following is a protective protein shell on the exterior of the envelope found in most archaea and some bacteria? A. S layer B. Outer membrane C. Pseudopeptidoglycan D. Cell wall E. Fimbriae

A. S layer

23. a -- Describe the layers and composition of the envelope of acid-fast bacteria such as Mycobacteria. (3 pts)

The cell wall of acid fast bacteria has a thick layer of a waxy lipid called mycolic acid. The cell wall also contains some proteins and a thin layer of peptidoglycan and another sugar layer.

5. Which of the following is found in the envelope of a Gram negative bacterium? A. a thin layer of peptidoglycan. B. a thick layer of peptidoglycan. C. a thick layer of mycolic acid D. an outer membrane containing lipopolysaccharide (LPS) E. A and D

E. A and D -- A. a thin layer of peptidoglycan. D. an outer membrane containing lipopolysaccharide.

17. Which of the following is a means used to power active transport in bacterial cells? A. Transport of water through a protein channel B. Transport of another ion along its concentration gradient (from high concentration to low concentration) C. Cleavage of phosphate off of phosphoenol phosphate (PEP) D. Cleavage of ATP E. B, C and D

E. B, C and D ---- B. Transport of another ion along its concentration gradient (from high concentration to low concentration) C. Cleavage of phosphate off of phosphoenol phosphate (PEP) D. Cleavage of ATP

10. Which of the following acts to inhibit the recycling of bactoprenol? A. Lysozyme B. Cephalosporin C. Vancomycin D. D-Cycloserine E. Bacitracin

E. Bacitracin

13. Which of the following is NOT true about the outer membrane? A. Contains lipopolysaccharide B. Contain phospholipids C. Almost all molecules that cross the membrane go through porin channel proteins D. Prevents some antibiotics from entering and acting against the bacteria E. Contains isoprenoids

E. Contains isoprenoids

17. Which of the following acts by inhibiting Ala racemase enzyme? A. Bacitracin B. Cephalosporins C. Vancomycin D. Lysozyme E. D-cycloserin

E. D-cycloserin

15. Which of the following is true? A. No cytoskeletal filaments have been found in bacteria B. Cytosketetal filaments have been found in bacteria but the bacterial cytoskeleton proteins are not similar to eukaryotic cytoskeleton proteins C. Cytoskeletal filaments have been found in bacteria but they are all formed from an homolog of eukaryotic actin D. Cytoskeletal filaments have been found in bacteria but they are all located on the outside of cells and are not similar to eucaryotic filaments. E. Different types of cytoskeletal filaments have been observed in bacteria and homologs to all three types of eukaryotic cytoskeletal proteins have now been found in bacteria

E. Different types of cytoskeletal filaments have been observed in bacteria and homologs to all three types of eukaryotic cytoskeletal proteins have now been found in bacteria

22. FtsZ does which of the following A. Causes expression of a mother cell specific set of genes B. Causes expression to occur only in the forespore C. Replicates the chromosome D. Initiation of sporulation E. Forms a ring at the cleavage site during cytokinesis

E. Forms a ring at the cleavage site during cytokinesis

19. Which of the following is NOT true? A. Chromosomal DNA has been found inside a membrane compartment in some bacterial cells. B. The chromosomal DNA of bacterial cells is bound by proteins that act to fold and compact the DNA. C. Chromosomal DNA appears to be folded into big loops. D. The location of chromosomal DNA within a bacterial cell can be observed with microscopy. E. Homologs of all the eukaryotic histone proteins have now been found in bacteria.

E. Homologs of all the eukaryotic histone proteins have now been found in bacteria.

1. Which of the following mediates attachment to surfaces, transfer of DNA between bacterial cells, and a form of motility? A. Flagella B. S layer C. Capsule D. Carboxysome E. Pili

E. Pili

4. Which of the following mediates attachment to surfaces, transfer of DNA between bacterial cells, and a form of motility? A. Flagella B. Slayer C. Capsule D. Carboxysome E. Pili

E. Pili

22. Which of the following is NOT true about flagellar swimming motility in bacteria? A. The motility is caused by the turning or spinning of flagella. B. The bacteria can move towards a desired food source (do chemotaxis) C. Most flagella can turn in either direction. D. The bacteria spinning of multiple flagella in a cell is coordinated. E. The bacteria move in a straight line to a desired food source

E. The bacteria move in a straight line to a desired food source

7. Which of the following is NOT a feature of the envelope of Archaea? A. The cell membranes of archaea are composed of isoprenoids instead of phospholipids B. Most archaea have a crystalline S protein layer C. Only some archaea have a cell wall with chains of sugar D. The cell wall of archaea is composed of pseudopeptidoglycan E. The cell wall of archaea contains mycolic acid

E. The cell wall of archaea contains mycolic acid

23. Describe the basic steps and their order in the synthesis of peptidoglycan murein by bacterial cells. (5 pts)

1. Synthesis N-acetyl-muramic (NAM) acid on UDP 2. Add five amino acids to one sugar (N-acetyl-muramic acid) in cytosol 3. Transfer sugar and pentapeptide to bactoprenol (undecaprenol) in membrane 4. Link other sugar (N-acetylglucoamine) to M with peptide attached to bactoprenol (C55) 5. Flip two sugar unit to outside of membrane 6. Two sugar unit is linked to a chain of peptidoglycan close to cell membrane 7. Form peptide cross bridge to sugars in another chain

26. Describe the basic order of events that occur in the assembly of a bacterial flagellum. You just need to describe the order in which different regions of the flagellum are assembled. (4 pts)

1. Two ring structures are formed in the cell membrane, the rod is added and then two more rings are added in the cell wall layer or outer membrane. 2. Hook section is added. 3. The filament is formed and new filament proteins are added to the tip of the flagella by passing through the basal body and the hollow filament.

25. You are medical doctor in Puerto Rico and a recent hurricane has knocked out the municipal water treatment facility and individuals are wanting to use untreated water from a nearby creek to drink. They have come to you to ask how they could treat the water to make it safe to drink. One person asks if they could treat the water with penicillin. The individual states he had recently been very sick but you had given him penicillin to treat the infection and you had said that penicillin kills bacteria. >> Give two reasons why treating the water with penicillin may not work to make the water safe to drink. (4 pts)

1. because the bacteria in the water may not be growing and penicillin only kills bacteria that are growing and synthesizing new cell wall material. 2. penicillin may not be effective against the type of bacteria causing the illess (Gm negative) 3. The bacteria in the water may be resistant to penicillin. You may not get penicillin up to high enough concentration

21. Which of the following is NOT true about the differences between the envelope observed in Archaeal bacteria and the envelope of Gram-positive bacteria? A. All Archaea have a S protein layer while no Gram-positive bacteria have a S layer. B. Some Archaea lack a cell wall while all Gram-positive bacteria have a cell wall. C. The cell wall of Archaea is composed of pseudopeptidoglycan instead of peptidoglycan. D. Archaea have isoprenoids in their cell membrane instead of phospholipids.

A. All Archaea have a S protein layer while no Gram-positive bacteria have a S layer.

11. Which of the following is a difference between Archaea and Bacteria? A. Archaea have isoprenoids in their membrane and bacteria do not B. Archaea have lipopolysaccharide in their membrane C. Archaea have mycolic acid in their cell wall D. Archaea have teichoic acid in their cell wall E. Archaea have murein peptidoglycan in their cell wall

A. Archaea have isoprenoids in their membrane and bacteria do not

4. Which of the following is true about motility in bacteria? A. Bacteria can tell if they are moving towards a food source B. Flagellated bacteria move in a straight line towards an attractant C. Flagella is the only mechanism of motility observed in bacteria D. All bacteria are motile E. In cells with multiple flagella, each one turns independently of the others

A. Bacteria can tell if they are moving towards a food source

3. What is different about the motility observed in spirochete bacteria from the typical flagellated bacteria? A. The flagella are located in the periplasm and wrap around the cell from each end. B. The motility is mediated by pili attaching and contracting. C. Their motility is based on sliding across a capsule or slime layer. D. They make little feet like projections that move to help the cell walk along a surface. E. The flagella do not rotate but instead wave back and forth

A. The flagella are located in the periplasm and wrap around the cell from each end.

12. You have performed a Gram stain on a microorganism isolated from a soil sample and the when the slide was observed in a microscope, you observed spheres about 1 mm in diameter that were purple in color. One would conclude the following: A. The isolate is most likely a Gram positive bacterium with a coccus shape B. The isolate is most likely a Gram negative bacterium with a coccus shape C. The isolate is most likely a Gram positive bacterium with a bacillus shape D. The isolate is most likely a Gram negative bacterium with a bacillus shape E. The isolate is most likely a Gram positive fungus with a spherical shape

A. The isolate is most likely a Gram positive bacterium with a coccus shape

1. Which of the following is a step of peptidoglycan synthesis inhibited by members of the penicillin (beta-lactam) family of antibiotics? A. The transpeptidase reaction B. The conversion of L-alanine to D-alanine C. The dephosphorylation of bactoprenol D. The synthesis of N-acetyl-muramic acid from fructose E. The linkage of the amino acid chain to the N-acetyl-muramic acid

A. The transpeptidase reaction

2. How do fimbriae or common pili differ from flagella? A. Thinner B. Longer C. Generally less fimbriae than flagella per cell D. Fimbriae filaments are assembled by adding to the tip while flagella are built by adding to the base E. Common pili are enclosed inside the cell membrane

A. Thinner

16. Which of the following is NOT a means used to power active transport in bacterial cells? A. Transporting a positive charged proton (H+ ) to the outside of the cell while transporting a molecule into the cell B. Transport of an ion along its concentration gradient (from high concentration to low concentration) while transporting a molecule into the cell. C. Cleavage of a phosphate off phosphoenolpyruvate (PEP) D. Cleavage of a phosphate off ATP

A. Transporting a positive charged proton (H+ ) to the outside of the cell while transporting a molecule into the cell

12. Which of the following is a form of motility observed in bacteria that is NOT mediated by flagella? A. Twitching motility on a surface B. Swimming motility in liquid C. Swarming motility on a surface D. Corkscrew, wiggling swimming motility of spirochetes in liquid E. C and D

A. Twitching motility on a surface

11. What is the S layer of bacterial cells? A. A polysaccharide coating observed in Gram positive bacteria B. A protein coating beyond the cell wall that is observed in some bacteria and archaea C. A waxy lipid coating in the envelope of acid fast bacteria D. An additional membrane observed in Archaea E. An internal membrane around sulfur granules

B. A protein coating beyond the cell wall that is observed in some bacteria and archaea

7. What is the S layer of bacterial cells? A. A polysaccharide coating observed in Gram-positive bacteria B. A protein coating beyond the cell wall that is observed in some bacteria and archaea C. A waxy lipid coating in the envelope of acid-fast bacteria D. An additional membrane observed in Archaea E. An internal membrane around sulfur granules

B. A protein coating beyond the cell wall that is observed in some bacteria and archaea

15. Homologs of eukaryotic cytoskeletons subunits play a role in which of the following in bacteria? A. Motility B. Cytokinesis and cell division C. Conjugation D. Transport of material into the cell E. C and D

B. Cytokinesis and cell division

20. In bacteria with an outer membrane, how do nutrients such as sugars, amino acids and ions cross the outer membrane so that they can be taken inside the cell? A. Diffusion directly through the lipid bilayer B. Facilitated diffusion through porin channel protein C. Active transport powered by ATP hydrolysis D. Active transport powered by ion-coupled transport E. All of the above

B. Facilitated diffusion through porin channel protein

14. Which of the following is NOT a function or role attributed to pili? A. Twitching motility B. Swarming motility C. Transfer of DNA during conjugation D. Attachment to a surface

B. Swarming motility

9. Which of the following is the part of peptidoglycan that varies the most between different species of bacteria (do not include Archaea)? A. The repeating sugars in the chain B. The amino acids in the third position of the peptide chain C. The linkage between the sugars D. The amino acid in position 4 of the peptide chain E. The linkage between the repeating sugars

B. The amino acids in the third position of the peptide chain

12. What is the principal reason why some members of the penicillin family are more effective against Gram positive bacteria than against Gram negative bacteria? A. Gram negative have a thinner peptidoglycan layer B. The antibiotic is not able to move through the outer membrane of Gram negative bacteria C. The antibiotic is not able to penetrate the mycolic layer of Gram negative bacteria D. Gram negative bacteria have a capsule while Gram positive do not E. The peptide in Gram negative is different

B. The antibiotic is not able to move through the outer membrane of Gram negative bacteria

8. What is the principal reason why some members of the penicillin family are more effective against Gram-positive bacteria than against Gram-negative bacteria? A. Gram-negative bacteria have a thinner peptidoglycan layer B. The antibiotic is not able to move through the outer membrane of Gram-negative bacteria C. The antibiotic is not able to penetrate the mycolic layer of Gram-negative bacteria D. Gram-negative bacteria have a capsule while Gram-positive do not E. The peptide in Gram-negative bacteria is different

B. The antibiotic is not able to move through the outer membrane of Gram-negative bacteria

15. What is unusual about the envelope of mollicutes like Mycoplasma? A. They use pseudopeptidoglycan instead of peptidoglycan B. They lack a cell wall of peptidoglycan C. They contain a layer of mycolic acid D. They contain an outer membrane E. All of the above

B. They lack a cell wall of peptidoglycan

5. Lysozyme acts to ______ A. cleave the sugars off lipopolysaccharide B. cleave the linkage between the sugars in peptidoglycan C. inhibit the synthesis of D-alanine D. inhibit the recycling of bactoprenol E. inhibit the transpeptidase reaction that crosslinks the peptide chains

B. cleave the linkage between the sugars in peptidoglycan

9. Peptidoglycan of bacteria is composed of _________ A. repeats of N-acetyl-glucose B. repeats of N-acetyl-glucosamine and N-acetyl-muramic acid C. repeats of N-acetyl-glucosamine and N-acetyl-talosaminuronic acid D. repeats of N-acetyl-glucose and N-acetyl-galactose E. repeats of N-acetyl-galactosamine and N-acetyl-uronic acid

B. repeats of N-acetyl-glucosamine and N-acetyl-muramic acid

19. What part of a flagellum is assembled first? A. Filament tip B. Hook C. Rings in the membrane D. Central rod E. Filament base

C. Rings in the membrane

20. One factor that causes septum formation and cytokinesis to occur in the center of bacterial cells is ______ A. the Min proteins forming a structure in the center of the cell B. the oscillation of Min proteins back and forth from each pole C. the Min proteins synthesizing new peptidoglycan in the center of the cell D. the Min proteins creating new membrane in the center of the cell E. the Min protein pulling the membranes toward the center of the cell

B. the oscillation of Min proteins back and forth from each pole

3. What of the following correctly describes the order in which the parts of a bacterial flagellum are assembled? A. Assembly starts with the tip of the filament. The filament is extended through the membrane, and then the hook is assembled and finally the basal bodies is placed in the cell membrane. B. The basal body (rings) is assembled first in the membrane, then the cell starts on the filament beginning with the tip and then after that assembles the hook C. Assembles basal body (rings) in membrane, then hook, then filament starting just above the hook and adds new filament proteins to the end of the extending filament and forms the tip of the filament last D. Assembles the hook, then extends the filament from the hook with the tip last, then assemble the basal body in the membrane E. None of the above

C. Assembles basal body (rings) in membrane, then hook, then filament starting just above the hook and adds new filament proteins to the end of the extending filament and forms the tip of the filament last

9. Which of the following is a similarity between lysozyme and penicillin? A. Both inhibit the synthesis of new peptidoglycan by blocking peptide crosslinking B. Both cleave the linkage between the sugars in the glycan chain C. Both can cause cell lysis by causing the development of holes in the peptidoglycan cell wall layer which allows the cell membrane to expand to far D. Both prevent the linkage the two sugars E. A and D

C. Both can cause cell lysis by causing the development of holes in the peptidoglycan cell wall layer which allows the cell membrane to expand to far

2. Which of the following is a similarity between penicillin and cephalosporin family members? A. Both inhibit bacterial ribosomes B. Both inhibit the recycling of bactoprenol C. Both form a structure similar to D-Ala-D-Ala D. Both bind to the pentapeptide E. B and D

C. Both form a structure similar to D-Ala-D-Ala

24. Which of the following is NOT true about cell division in bacterial cells? A. Most bacteria divide by binary fission B. Some bacteria reproduce by budding C. During cell division, constriction, septation and cytokinesis always occur together (at same time) D. Some bacteria can produce multiple offspring E. Some bacteria produce non-identical offspring due to asymmetrical cell division

C. During cell division, constriction, septation and cytokinesis always occur together (at same time)

5. Which of the following has NOT been observed in the interior of bacterial cells? A. Gases within a protein shell B. Granules or aggregates of polyhydroxyalkanoates such as poly-B-hydroxybutyrate C. Granules of mycolic acid D. Granules of elemental sulfur E. Crystals of iron magnetite

C. Granules of mycolic acid

16. Which of the following is NOT true? A. DNA has been found inside a membrane compartment in bacteria B. Proteins interact with DNA in the bacteria cell to help fold and compact the DNA C. Homologs of all the eukaryotic histone proteins have been found in bacteria D. The location of DNA in bacterial cells is visible in electron micrographs E. None of the above (all are true).

C. Homologs of all the eukaryotic histone proteins have been found in bacteria

13. Which of the following is found only in the outer membrane of Gram-negative bacteria? A. Mycolic acids B. Teichoic acids C. Lipopolysaccharide D. Peptidoglycan E. A and B

C. Lipopolysaccharide

21. MinC, MinD, and MinE act in which of the following? A. Stringent response B. The initiation of sporulation C. Making the septum and cell division occur in the center of the cell D. Catabolite repression E. Form the cleavage ring

C. Making the septum and cell division occur in the center of the cell

14. Which of the following has NOT been observed in bacteria? A. Rod shaped bacteria with a single polar (at one end) flagellum B. Rod shaped bacteria with multiple flagella spread over their entire body C. Rod shaped bacteria with all their flagella enclosed inside the cell or inner membrane D. Rod shaped bacteria with a single flagellum on each end E. Rod shaped bacteria with multiple polar flagella (all stick out of one end)

C. Rod shaped bacteria with all their flagella enclosed inside the cell or inner membrane

4. Homologs of which of the following subunits that form cytoskeleton filaments in eukaryotic cells have now been found in bacterial cells? A. Actin B. Tubulin C. Intermediate filaments D. All three (A, B and C) E. None

D. All three (A, B and C) ----- A. Actin B. Tubulin C. Intermediate filaments

10. Which of the following is NOT found in the envelope of acid fast bacteria like Mycobacteria? A. A layer of peptidoglycan B. A layer of arbinan-galactan sugars C. A layer of mycolic acid D. An outer membrane E. A membrane with a bilayer of phospholipids

D. An outer membrane

6. Which of the following is NOT found in the envelope of acid-fast bacteria like Mycobacteria? A. A layer of peptidoglycan B. A layer of arabinan-galactan sugars C. A layer of mycolic acid D. An outer membrane containing phospholipids and lipopolysaccharide E. A membrane with a bilayer of phospholipids

D. An outer membrane containing phospholipids and lipopolysaccharide

19. Pseudopeptidoglycan is found in ________ A. Cell membrane of Archaeal bacteria B. Cell wall of Gram negative bacteria C. Cell wall of Gram positive bacteria D. Cell wall of Archaeal bacteria E. Cell wall of acid fast Mycobacteria

D. Cell wall of Archaeal bacteria

1. Which of the following is a difference in the composition of the peptidoglycan murein found in Gram-positive bacteria verse the murein found in Gram-negative bacteria? A. One of the sugars is different B. The linkage between the sugars is different [beta-(1-3) instead of beta-(1,4)] C. Gram positive only have D-amino acids in their peptide chain D. In Gram positive, the peptide chains from the sugars are cross-linked via five glycine (Gly) amino acids E. In Gram positive, the peptide from the sugar is two amino acids long

D. In Gram positive, the peptide chains from the sugars are cross-linked via five glycine (Gly) amino acids

23. Which of the following acts to prevent septum formation and cell division from occurring near the poles instead of in the center of the cell? A. FtsA B. FtsZ C. ParA/B Type I system D. MinC, D and E E. Toxin-antitoxin pathway

D. MinC, D and E

20. Which of the following would be the weakest evidence that a bacterium is motile via flagellum? A. Observing that the bacteria can move through a soft motility agar B. Observing live bacteria moving within a drop of untreated liquid media with a light microscope C. Observing structures that look like flagellum with an electron microscope image D. Observing the presence of two genes in its genome that encode proteins that have some similarity to proteins found in the flagellum of E. coli E. Observing flagellum around the bacteria when the bacteria was stained with a flagellar stain

D. Observing the presence of two genes in its genome that encode proteins that have some similarity to proteins found in the flagellum of E. coli

2. Which of the following is found only in the cell wall of Gram-positive bacteria? A. Lipopolysaccharide B. Mycolic acid C. Isoprenoids D. Teichoic acid E. A and B

D. Teichoic Acid

18. Which of the following is NOT part of or a component in the envelope of a Gram negative bacterium? A. Peptidoglycan B. Outer membrane C. Lipopolysaccharide (LPS) D. Teichoic acid E. Periplasm

D. Teichoic acid

6. Which of the following is found only in the cell wall of Gram positive bacteria? A. Lipopolysaccharide B. Mycolic acid C. Isoprenoids D. Teichoic acid E. A and B

D. Teichoic acid

10. Which of the following describes how new peptidoglycan is synthesized? A. Individual sugars are transported across the cell membrane, the sugars are added to the peptidoglycan chain one at time, and then amino acids are added to the sugars. B. Amino acids are added to one sugar. Each sugar is transferred across the cell membrane individually and then added to existing peptidoglycan one at a time. C. A four sugar unit is assembled in the cytoplasm, amino acids are added and then cross linked. The four sugar unit is then transferred across the cell membrane, and then linked the sugars linked to the existing peptidoglycan D. The amino acids are added to one of the sugars, the other sugar is linked to the sugar with the peptide, the two sugar unit is transferred across the cell membrane, the two sugar unit is linked to the existing peptidoglycan, and the peptide cross link is formed

D. The amino acids are added to one of the sugars, the other sugar is linked to the sugar with the peptide, the two sugar unit is transferred across the cell membrane, the two sugar unit is linked to the existing peptidoglycan, and the peptide cross link is formed

14. Which of the following describes how new peptidoglycan is synthesized? A. Individual sugars are transported across the cell membrane, the sugars are added to the peptidoglycan chain one at time, and then amino acids are added to the sugars. B. Amino acids are added to both sugar. Each sugar is transferred across the cell membrane individually and then added to existing peptidoglycan one at a time. C. A four sugar unit is assembly in the cytoplasm, amino acids are added and then cross linked. The 4 sugar unit is then transferred across the cell membrane, and then linked the sugars linked to the existing peptidoglycan D. The amino acids are added to one of the sugars, the other sugar is linked to the sugar with the peptide, the two sugar unit is transferred across the cell membrane, the two sugar unit is linked to the existing peptidoglycan, and the peptide cross link is formed

D. The amino acids are added to one of the sugars, the other sugar is linked to the sugar with the peptide, the two sugar unit is transferred across the cell membrane, the two sugar unit is linked to the existing peptidoglycan, and the peptide cross link is formed

6. Mycolic acid is found in ______ A. in the peptidoglycan layer of Gram-positive bacteria B. in the peptidoglycan layer of Gram-negative bacteria C. in the outer membrane of Gram-negative bacteria D. in the envelope of acid-fast bacteria E. in the membrane of Archaea bacteria

D. in the envelope of acid-fast bacteria

17. Lipopolysaccharide is found _________ A. in the peptidoglycan layer of Gram positive bacteria B. in the inner membrane of Gram negative bacteria C. in the cell wall of mycobacterium D. in the outer leaflet of the outer membrane of Gram negative bacteria E. on the exterior of Archaea bacteria

D. in the outer leaflet of the outer membrane of Gram negative bacteria

11. Pseudopeptidoglycan is found in ________ A. the cell membrane of Archaeal bacteria. B. the cell wall of Gram-negative bacteria. C. the cell wall of Gram-positive bacteria. D. the cell wall of Archaeal bacteria. E. the cell wall of acid-fast Mycobacteria.

D. the cell wall of Archaeal bacteria.

3. Which of the following is NOT a feature of bacterial flagella? A. A cell can have several flagella B. Each flagellum turns like a propeller C. The flagellum is assembled from inside to outside with filament subunits adding to the end of the filament D. Movement is characterized by short runs and tumbles E. The turning is powered or driven by ATP cleavage

E. The turning is powered or driven by ATP cleavage

7. For phosphotransferase transport/group translocation, the energy for transport of sugars into cells comes from ______ A. proton gradient due a high concentration of protons on the outside of the membrane B. cleavage of ATP by the membrane protein C. transfer of a phosphate from ATP to the outside of the cell D. phosphate gradient due to higher concentration of phosphate on the outside of the cell E. cleavage of phosphate from PEP and transfer of the phosphate to the sugar by a series of proteins as it comes into the cell

E. cleavage of phosphate from PEP and transfer of the phosphate to the sugar by a series of proteins as it comes into the cell

27. Describe two examples of compartments that have been found inside bacterial cells. Describe their structure and their role. You can include a drawing. (4 pts)

Possible examples include 1. Thylakoids and chlorosomes - Membrane compartments involved in photosynthesis with a full bilayer or single monolayer (chlorosome) 2. Carboxysomes - membrane and sites of reactions involved in carbon fixation 3. Gas vesicles which store gases inside a protein shell 4. Membrane surrounding DNA in one type of bacteria 5. Endospore formation

30. -Describe two examples of compartments that have been found inside bacterial cells. -Describe their structure and their role. You can include a drawing. (4 pts)

Possible examples include 1. Thylakoids and chlorosomes - Membrane compartments involved in photosynthesis with a full bilayer or single monolayer (chlorosome) 2. Carboxysomes - membrane and sites of reactions involved in carbon fixation 3. Gas vesicles which store gases inside a protein shell 4. Membrane surrounding DNA in one type of bacteria 5. Endospore formation

23. b -- How does it composition alter the properties of those bacterial cells? (2 pts)

The mycolic acid makes the cells very resistant to many chemicals such as disinfectants, antibiotics, acids and to environmental stresses such as drying. It may also slow growth of the cells as it may limit the uptake of nutrients.

27. You have isolated a potential new species of bacterium. You have done a Gram stain and observed pink cells and have sequenced the genome. a. What could you look for in the predicted function in gene annotations to support the observation that the organism is Gram negative? (2 pts)

a. Can look for genes predicted to produce outer membrane porin proteins, enzymes for lipopolysaccharide (LPS) production, enzymes for peptidoglycan synthesis (not unique to Gm negative), periplasmic proteins.

27. You have isolated a potential new species of bacterium. You have done a Gram stain and observed pink cells and have sequenced the genome. b. Name one other experiment or technique one could you use to determine the envelope structure of the bacterium? (2 pts)

b. Electron microscopy, selective media, resistance to chemicals, isolate components of envelope (LPS)

How is Pseudopeptidoglycan different from Gm neg. peptidoglycan?

• A different sugar • Linkage of sugar different • Peptide crosslink different - all L-amino acid • Two sugars: N-acetyl-glucosamine (NAG) and (N- acetyltalosaminuronic acid) - NAT • β-1-3 linkage • Peptide cross link - All L-amino acids

26. Explain the number and arrangement of flagella that have been observed in bacterial cells and how they act to cause motility in bacteria. (4 pts)

• Bacteria can have one to several flagella and they can be found on one end, both ends of cells or all over the cell. • In spirochetes the flagella do not extend out from the cell but instead are wrapped around the cell in the periplasm. • The cause motility by turning around at its base and the long tail then rotates around causing motility.

30. Describe the process of cytokinesis in Gram negative rod bacterium mentioning the role of the FtsZ protein. (4 pts)

• Begins after DNA is replicated and segregated to opposite poles of cell. • Then the FtsZ forms a cytoskeketal filament ring at the cleavage site usually in the center of the cell. • Many other proteins associate with the FtsZ ring. • The ring then starts to constrict which leads to the invagination of the inner and outer membrane. • Septation and cytokinesis occurs together.

25. List two ways a bacterial cell can resist or be resistant to the effects of an antibiotic like penicillin. (3 pts)

• Block uptake of the antibiotic by outer membrane or envelope or lack of transport factor • Produces an enzyme that cleaves the antibiotic • Produce proteins that binds the antibiotic and keeps it from working • Target of antibiotic could change so it no longer • Pump antibiotic out of the cell • Lack of cell wall or target of the drug

27. What is the composition of the glycocalyx capsule and what are two roles it plays for bacterial cells? (4 pts)

• Composed of sugar and/or protein and maybe DNA • Roles are attachment to surfaces, protection from phagocytosis, protection from desiccation and matrix for formation of biofilms.

28. You have isolated a new bacterial species from the gut of an insect. You did a Gram stain and the cells were purple. Describe two techniques or experiments one could do to support or confirm that the bacterial strain has a Gram-positive envelope. (3 pts)

• Do transmission Electron microscopy and observe a thick peptidoglycan layer and no outer membrane • Try to isolate teichoic acid from the cell wall of the bacteria • Test for sensitivity to a penicillin which is more effective against Gm + but not Gm - • Observe no growth on a selective media for Gram negative • Look at predicted genes in genome and look are absence of genes for LPS synthesis, outer membrane and periplasmic proteins and genes for synthesis of teichoic acid.

29. Describe the layers and the components found in each layer of the envelope of a Gram negative bacterium. (5 pts)

• Glycocalyx or capsule composed of sugars or proteins • Outer membrane composed of lipopolysaccharide (LPS), proteins, phosphoplipids • Cell wall composed of peptidoglycan Periplasm • Cell membrane composed of phospholipids and proteins

31. Describe the layers and the components found in each layer of the envelope of a Gram-negative bacterium. You can include a drawing. (5 pts)

• Glycocalyx or capsule composed of sugars or proteins • Outer membrane composed of lipopolysaccharide, proteins, phosphoplipids • Cell wall composed of peptidoglycan • Periplasm • Cell membrane composed of phospholipids and proteins

30. Describe two mechanisms bacterial cells use to transport chemicals such as sugars across the cell membrane into the cell. (3 pts)

• Ion coupled transport - transport one substance by using ion gradient along with it in the same or opposite direction through an transport protein • ABC transporter - protein binds substance in periplasm and brings to ABC transporter and it transports it into cell using ATP to drive the transport • Phosphotransferease transport or group translocation - transport sugar in and then phosphorylate it by a phosphate transfere from several protein in the phosphotransferease system • Carrier or channel proteins for facilitated diffusion for transport with concentration gradient

28. Describe two ways one could use to test if a bacterium is motile? (4 pts)

• Motility tube test • spreading across a plate, observe live cells under the microscope • stain for flagellum • look for flagella in electron microscope • look for flagelular genes in predicted genes

22. Explain how members of the penicillin family of antibiotics act against bacteria. (4 pts)

• Penicillin family members inhibit the synthesis of new peptidoglycan. • Penicillin structurally are similar to the Ala-Ala in the peptide of peptidoglycan and inhibits the action of transpeptidase enzyme and maybe the transglycoslyation enzyme. • The inhibition of peptidoglycan synthesis will ultimately lead to holes in the peptidoglycan layer which will usually result in the lysis of the cell when the membrane expands to far.

24. Describe two other forms of motility seen in bacteria besides the motility mediated by the typical flagella sticking out from the cell? Give a description of how motility occurs in each example. (4 pts)

• Periplasmic flagella - flagella are located in periplasm, rotation causes wiggling, helical motility • Swarming motility - a group of flagellated bacteria move together over a solid surface inside a slime layer • Gliding motility - movement of cells over a solid media that is not mediated by flagella • Twitching motility = movement of cells over a surface mediated by Type IV pili attaching and pulling the cell forward

26. List three examples of structures larger than a single protein that have been found in the cytoplasm of bacterial cells and describe the role or function of each. (6 pts)

• Ribosomes - protein synthesis • Nucleoid - Packed DNA with proteins - genetic material • Storage granule or inclusion - storage of energy or food sources • Membrane vesicle or structures - with a role in metabolism, usually photosynthesis • Vesicle for gas in aquatic bacteria, • Carboxysomes or Chlorosomes - photosynthesis • Cytoskeleton filaments - cell division and/or cell shape

25. Describe one way a bacterium could be motile even if it lacked any flagellum. Describe how the motility is mediated. (4 pts)

• The bacteria could move across a surface via twitching motility or gliding motility. • Twitching motility is mediated by type IV pili which extend out, attach to a surface and then shorten which pulls the cell forward. • In gliding motility, protein extend out of the cell and the proteins move so that cells walks on them over the surface.

24. You have isolated a new bacterial species from the gut of an insect. You did a Gram stain and it was pink. Describe two techniques or experiments one could do to support or confirm that the bacteria has an envelope with a Gram negative arrangement. (4 pts)

• Transmission Electron microscopy and look for an outer membrane • Try to isolate lipopolysaccharide from the bacteria • Attempt to isolate an outer membrane by doing density gradient centrifugation • Detect presence of outer membrane porin proteins Test for sensitivity to penicillin which is effective against Gm + but not Gm - • Grow on a selective media for Gram negative

21. What is the composition of the glycocalyx capsule and what are two roles it plays for bacterial cells? (4 pts)

•Composed of sugar and/or protein and maybe DNA •Roles are attachment to surfaces, protection from phagocytosis, protection from desiccation and matrix for formation of biofilms.