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Final Exam Stephen Jad
Final exam
57
Microbiology
Undergraduate 4
12/16/2013

Additional Microbiology Flashcards

 


 

Cards

Term

1.Prokaryotes are made up of which two groups?

A. Bacteria and fungi

B. Bacteria and archaea

C. Protozoa and animals

D. Archaea and fungi

 

2.Ribosomal RNA-based studies reveal that

A. All eukaryotic organisms are related but that all prokaryotic organisms are not necessarily related. 

B. The arachaea are most closely related to the viruses. 

C. All prokaryotic organims are related but that all eukaryotic organisms are not necessarily related. 

D. All organisms are thought to have diverged from a common ancestral organism. 

Definition

1. B

2. D

Term

3. What type of energy-yielding metabolism is found only in prokaryotes?

A. Chemoorganotrophy

B. Chemolithotrophy

C. Phototrophy

D. Autotrophy

 

4. The three options by which an organism may obtain energy are _____, ______, and ______?

 

5. The first documented description of a microorganism was of a ______ by ________. 

Definition

3. B 

4. Phototrophy, Chemoorganotrophy, and chemolithotrophy

5. Fungi, robert hooke. 

Term

1. The predatory bacterium bdellovibrio bacteriophorus, drills into a prey bacterium and once inside, digests it. In an attack upon a gram-positive bacterium that has a slimy cell covering which can inhibit phagocytosis, what is the correct sequence of structures penetrated by B. bacteriophorus on its way to the prey's cytoplasm?

1.Membrane composed mostly of lipopolysaccharide

2. membrane composed mostly of phospholipids

3. peptidoglycan

4. capsule

5. periplasm

A. 4->1->3->6

B. 4->5->3->2

C. 4->3->2

D. 1->3->5->2

E. 1->4->3->2

Definition

1. C 

Term

2. Which statement about the genomes of prokaryotes is correct?

A. Prokaryotic cells have multiple chromosomes, "packed" with a relatively large amount of protein. 

B. The prokaryotic chromosome is not contained within a nucleus but, rather, is found at the nucleoid region. 

C. Prokaryotic chromosomes are somtimes called plasmids. 

D. Prokaryotic genomes are composed of linear DNA. 

E. Prokaryotic genomes are diploid throughout most of the cell cycle. 

F. B and C are correct. 

Definition

2. B

Term

3. Which of these statements is true?

A. The gram-positive wall contains a thick peptidoglycan layer and is more complex than the gram negative wall. 

B. The gram positive wall contains a thick peptidoglycan layer but is about as complex as the gram negative wall.

C. The gram-positive wall contains a thick peptidoglycan layer but is less complex than the gram-negative wall. 

D. The gram0negative wlal contains a thick peptidoglycan layer and is more complex than the gram-positivie wall. 


4. The peptide interbridge crosslinking is found only in the cell walls of ________.

5. The major contituents of the lipids in Bacteria and Eukarya are _______, whereas lipids in Archaea contain _______. 

Definition

3. C

4. Gram positive bacteria 

5. fatty acids, isoprenes

Term

1. The molecule that functions as the reducing agent in a redox reaction

A. Gains electrons and loses energy 

B. Loses electrons and gains energy 

C. Neither gains nor loses electrons but gains or loses energy

D. gains electrons and gains energy

E. loses electrons and loses energy

 

2. During electron transport reactions, 

A. OH- accumulates on the inside of the membrane while H+ accumulates on the outside

B. OH- accumulates on the outside of the membrane while H+ accumulates on the inside. 

C. Both OH- and H+ accumulates on the inside of the membrane. 

D. Both OH- and H+ accumulate on the outside of the membrane 

E. electrons are pumped across the membrane 

 

 

Definition

1. E

2. A

Term

3. The ATP made during glycolysis is generated by 

A. Electron transport

B. photophosphorylation

C. Substrate level phosphorylation

D. oxidation of NADH to NAD+

E chemiosmosis 


4. During cellular respiration in prokaryotes acetyl CoA accumulates in which location?

A. mitochondial matrix

B mitochondrial outer membrane

C. mitochondrial inner membrane 

D. cytosol

E. mitochondrial intermembrane space 

Definition

3. C

4. D

 

Term

5.The primary role of oxygen in aerobic cellular respiration is to 

A. combine with lactate, forming pyruvate. 

B. yielding energy in the form of ATP as it is passed down the respiratory chain. 

C. combine with carbon forming CO2 

D. act as an acceptor for electrons and hydrogen forming water. 

E. catalyze the reactions of glycolysis 

 

6. One example of an elctron acceptor that can be used in anaerobic respiration is 

A. NADH

B. Pyruvate

C. water

D. nitrate

E. Both B and D are correct

 

 

 

Definition

5. D

6. E

 

Term

1. A microbe growing in a refrigerator is likely a 

A. hyperthermophile

B. thermophile

C. psychrophile

D. mesophile

 

2. Formation of the divisome begins with the attachment of which protein in a ring round the center of the cell?

A. FtsZ

B. MinE

C. MinC

D. ZipA

Definition

1. C (Hyperthermophile= very hot, thermophile= hot, psychrophil= cold loving, mesophile= medium temperature)

2. A 

 

Term

3. What is the function of bactoprenol?

A. It is responsible for forming the peptide cross-links between muramic acid residues in adjacent glycan chains. 

B. It triggers the recruitment of FtsZ and the initiation of the divisome. 

C. It is a hydrophobic alcohol that transports peptidoglycan precursors across the cytoplasmic membrane

D. It supplies the energy necessary for transpeptidation to occur. 

 

4. The most common type of continuous culture device is called a ___.

 

5. Bacillus subtilis encoding mutation that inactivates the protein MreB look microcopically as _____.

Definition

3. C

4. Chemostat

5. cocci

 

Term

1. In all cells, genes are composed of 

A. Chromosomes 

B. nucleic acids

C. proteins

D. mRNA


2. In all cells a gene encodes for 

A. a tRNA 

B. a protein (via mRNA)

C. an rRNA 

D. all of the above. 


3. The processes of transcription and translation are coupled processes in 

A. prokaryotic cells

B. eutkaryotic cells

C. both eukaryotic and prokaryotic cells. 

D. neither eukaryotic nor prokaryotic cells. 

Definition

1. B

2. D

3. A

Term

4. A group of genes that are transcribed together is called a(n) ______, which is transcribed as a(n) _______.

 

5. Cells that have two of each cchromosome are ______, whereas cells that have only one copy of each chromosome are _____. 

 

1. an important sequence in the initiation of transcription in Bacteria is the 

A. start codon

B. termination site

C. TATA box

D. Pribnow box

 

Definition

4. operon, polycistronic mRNA

5. diploid, haploid

1. D

 

Term

2. In negative control of transcription, how does the presence of an inducer affect transcription?

A. The inducer prevents the repressor from binding to the operator. 

B. The inducer does not bind to the operator.

C. The inducer causes the repressor to bind to the operator. 

D. The inducer binds to the operator. 

 

3. The entire copmlement of RNA produced under a given set of conditions is called a(n)

A. metabolome 

B. proteome

C. genome

D. transcriptome. 

Definition

2. C

3. D

Term

4. The main process in control of gene expression in Bacteria occurs at the level of ________.

 

5. The holoenzyme is composed of a _______, which binds to a DNA sequence upstream of the gene to be transcribed called a(n) _______ promotor, and a(n) ________, which catalyzes the formation of an RNA molecule. 

Definition

4. Transcription

5. transcription factor, promotor, RNA polymerase

 

Term

1. The most widely used molecule in sequence-based evolutionary analysis for prokaryotes and eukaryotes is 

A. transpeptidase. 

B. rRNA genes. 

C ATPase

D cytochrome C. 

 

2. An oil-oxidizing microorganism called _______ is known to secrete _______ that assists the microbe in internalizing the oil. 

 

3. Microbial production of petroleum occurs in such organisms as _______, which is a ________ in terms of catabolic metabolism. 

 

4. Microbial leaching of ore can be performed by _______, which is a ________ in terms of catabolic metabolism. 

Definition

1. B

2. Alcanivorax Burkumensis, glucose-lipid surfactant

3. ¡Botryococcus braunii, phototroph

4    4. Acidithiobacillus ferroxidans, chemolithotroph


Term

1. The identification of the first bacterial cells was the result ofwork by 

A. psteur

B. Hooke

C. Cohn

D. Koch

E. van Leeuwenhoek

 

2. Which statement about gram-negative bacteria is correct? 

A. Their cell walls are primarily composed of peptidoglycan. 

B. Their plasma membranes are composed of glycerol diethers. 

C. They often possess an outer membrane containing toxic lipopolysacharides. 

D. Their chromosomes are composed of DNA tightly wrapped around large amounts of histone protein. 

E. Their cell walls are composed of a periplasm, an outer membrane and pseudo murein. 

Definition

1. E

2. C

 

Term

3. Viral replication occurs

A. intracellularly

B. extracellularly

C. both intra- and extracellularly

D. either intracellularly or extracellularly, depending on the virus involved. 

 

4. The beta lactam antibiotics

A. inhibit eukaryotic microbes

B. do not inhibit MRSA strains

C. inhibit plasma membrane sythesis 

D. enable beta lactamases to be synthesized. 

Definition

3. A

4. B

 

Term

5. A prophage replicates

A. along with its host as long as the genes activating its lytic genes are not expressed 

B. independently of its host as long as the genes activating its lytic genes are not being expressed

C. independently of its host as long as the genes activating its lytic genes are being expressed 

D. along with its host as long as the genes activating its lytic genes are being expressed

 

6. which of the following are the hosts for most envoloped viruses

A. Archaea 

B. fungi

C. animals

D. Bacteria 

E. plants 

Definition

5. A 

6. C

 

Term

7. Disease causing prokaryotes are found exclusively among the 

A. Bacteria 

B. Arcaea 

C. viruses

D. Fungi 

E. both A and C

 

8. Negatively charged molecules that are partially responsible for the negative charge of the gram-positive bacterial cell surface are

A. phospholipids

B. diaminopimelic acids

C. Teichoic acids. 

D. peptide interbridges

E. lipopolysaccharide

Definition

7. A

8. C

 

Term

9. When does endospore formation commence?

A. when bacteria are dividing expontentially

B. following bacterial death

C. when bacterial growth ceases due to limitation of an essential nutrient. 

D. when the bacterium is undergoing binary fission 

E. after germintaiton of a vegetative cell

 

10. Regarding membrane linkages, which statement is true?

A. Bacteria and Eukarya have ester linkages; Arcaea linkages rae not yet known. 

B. Archaea have ester linkages; Eukarya have ether linkages. 

C. Bacteria and Eukarya have ester linkages; archaea have ther linkages. 

D. Eukarya have ester linkages; Bacteria have ether linkages. 

 

Definition

9. C

10. C

 

Term

11. The ultimate downfall of the theory of spontaneous generation was the result of work by

A. hooke             B. pasteur             C. koch

D. van Leeuwenhoek           E. winogradsky

Following questions refer to structures found in a gram-positive prokaryotic cell

12. Not presint in all bacteria, this cell covering enables cells that possess it to resist the defenses of host organism

A. pseudomurien         B. capsule            C. endospore

D. nucleoid                        E. Cell wall 

13. The structure that contains genetic information: 

A. Capsule               B. cell wall                  C. flagellum

D. nucleoid                          E. endospore  

Definition

11. B

12. B

13. D and E

 

Term

14. Which of the following traits do Eukarya and Bacteria share?

1. compostion of the cell wall

2. presence of plasma membrane 

3. lack of uclear envelope 

4. identical rRNA sequences 

5. presence of a mitochondria 

 

15. Carl Woese and collaborators created the tree of life and identified two major  banches of prokaryotic evolution. What was the basis for dividing prokaryotes into two domains? 

A. Genetic characteristics such as ribosomal RNA sequences

B. microscopic examination of staining characteristics of the cell wall

C. ecological characteristics such as the ability to survive in extreme environments

D. metabolic characteristics such as chemoautotrophy and photosynthesis

E. metabolic characteristics such as the production of methane gas. 

Definition

14. E

15. A

Term

16. Germ free mice were used in the paper by Riduara et al. (2013) because 

A. These mice are free of disease causing pathogens

B. these mice are inexpensive and simple to use in an experimental model

C. these mice contain no gut associated bacteria 

D. these mice eat their own feces

E both A and C

Definition

16. E

Term

Virus: Inhibits protein synthesis: Genome as mRNA: polymerase present

A, DNase, - , -

B, RNase, + , -

C, DNase, - , +

D, RNase, - , + 

E, RNase, - , - 

 

17. Which virus meets the baltimore requirements for a retrovirus? 

 

18. Which virus meets the baltimore requirements for a positively stranded RNA virus?


19. Which virus meets the baltimore requirements for a DNA virus?

 

Definition

17. C

18. B

19. A

 

Term

20. Two types of pathogens in which Koch's postulate could not be used to identify the microbe successfully are _______ and _______.


21. Transcription and translation are spatially separated processes in _______ cells because the _______ is located in the nucleus and the _______ is in the cytoplasm. 


22. Regarding the viral membrane in an enveloped virus, the lipids are derived from the _______ and the proteins are encoded by the _____. 

 

Definition

20. Viroids, prions

21. Eukaryotic, DNA, ribosome

22. host cell, viral genome

 

Term

23. The enzyme involved in the transfer of RNA to DNA is _________. 

 

24. The two proteins on the influenze virus surface are known as _______ and ________.

 

25. Transmissible spongiform encephalopathies are caused by _______. 

 

26. Endospores are _______ structures that are significantly different than vegatative cells because of the presence of _______ and ________. 

Definition

23. Reverse transcriptase

24. hemagluttinin, neurominidase 

25. prions

26. resistant, SASP, Ca2+

Term

Draw covering of a gram positive bacteria and a gram negative bacteria. 

Definition
[image]
Term

Viruses are obligate intracellular parasites and require host cell machinery to successfully replicate their genomes and create infectious virions. However, certain viruses contain enzymes within the virion while other viruses do not. Why? A complete answer will include which virus types listed below must contain enzymes within the virion and which virus types do not need to contain an enzyme. In addition, include what ype of enzyme replicates each of the viral genomes from the list below and whether this enzyme is derived from the host or the viral genome. (table)

Definition
[image]
Term

Construct a table that organizes the following terms and label the columns and rows. 


phosphodiester linkages, polypeptides, monosaccharides, found in bacteria


peptide bonds, lipids,  nucleotides, found in archaea


glycosidic linkages, nucleic acids, amino acids, found in eukarya 


ester linkages, polysaccharides fatty acids found in all viruses. 

Definition
[image]
Term

1. During the _____ of growth new cells are being produced at the same rate as other cells are dying. 

A. lag phase

B. exponential phase

C. death phase

D. stationary phase

E. lag and stationary phase

 

2. DNA sequences may be introduced into a recipient by which of the following?

A. conjugation

B. transduction

C. transformation

D. gene transfer agents

E. All of the above. 

 

Definition

1. D

2. E

 

Term

3. When the population double during a constant time interval, the growth is said to be 

A. semilogarithmic

B. exponential 

C. linear 

D cartesian 

 

4. Under what conditions would a lag phase not occur but cells will still continue to divide?

A. when an exponentially growing culture is transferred into fresh medium

B when culture is transferred from a rich medium to a minimal medium that lacks an essential nutrient.

C. When a culture subjectedd to UV light, which causes DNA damage, is transferred into fresh medium.

D. when a stationary phase culture is transferred into fresh medium. 

Definition

3. B

4. A

Term

5. The metabolic processes called fermentation 

A. produce substrates for the CTA

B. use an organic molecule as a terminal electron acceptor. 

C. occur when oxygen is readily available. 

D. produces reduced electron carriers for glycolysis

E. both B and D

 

6. Which of the following statements concerning cellular metabolism is false?

A. energy obtained from nutrients or light is stored in the bond of ATP 

B. enzymes are used both in catabolic and anabolic reactions. 

C macromolecules are converted into cell structures via catabolism. 

D. the goal of metabolism is reprocution of the organism. 

E. ATP is hydrolyzed in the process of anabolism. 

Definition

5. B

6. C

Term

7. Which of the following can be the terminal electron acceptor used in anaerobic respiration in bacteria.

A. sulfate (SO4)    B. pyruvate (c3H4O3)   C.nitrate (NO3)

D. Oxygen (O2)    E. both pyruvate and sulfate. F. both nitrate and sulfate


8. The uptake of DNA released from a cell would most likely be the result of _______, while cell-to-cell contact would most likely result in _______. 


9. Which of the following statements describes NAD+?

A. NAD+ has more chemical energy than NADH

B. NAD+ is reduced to NADH during both glycolysis and the CAC.

C. NAD+ can donate electrons for use in oxidative phosphorylation.

D. In the absence of NAD+ glycolysis can still function

E. NAD+ is reduced by the action o fhydrogenases. 

Definition

7. F

8. D

9. B

 

Term

10. A plasmid may 

A. replicate independently of the chromosome. 

B. be integrated into the chromosome

C. be transferred cell to cell during conjugation

D. be involved in any of the above

 

11. which is not a reason why gene expression is fundamentally different in eukaryotes compared to prokaryotes? 

A. Eukaryotic mRNA's get 5' caps and poly-adenylated tails

B. Eukaryotic exons may be spliced together in the cytosol to form a mature mRNA

C. prokaryotic genes can be expressed as polycistronic mRNA's 

D. Eukaryotic RNA polymerases replicate mature mRNAs in the nucleus 

E. prokaryotes use ribosomes of different structure and size than eukaryotes 

F. both B and D

Definition

10. D

11. B

Term

12. The roadblock created by the formation of a reduced electron carrier is overcome in fermentation by the 

A. oxidation of NAD+ back to NADH

B. reduction o NADH back to NAD+ 

C. oxidation o NADH back to NAD+ 

D reduction of NAD+ back to NADH

 

13. In hypothetical situation, the genes for sex pilus construction and for tetracycline resistance are located together on the same plasmid within a particular bacterium. If this bacterium readily performs conjugation involving a copy of this plasmid then the result should be. 

A. The rapid spread of tetracycline resistance to other bacteria in that habitat. 

B. The production of endospores among the bacteriums progeny. 

C. a transformed bacterium. 

D the temporary possession by this bacterium of a completely diploid genome. 

E. The subsequent loss of tetracycline resistance from this bacterium. 

Definition

12. C

13. A

Term

14. Human pathogens are classified as 

A. mesophiles          B. psychrophiles        C. thermophiles

D. thermoduric      E. hyperthermophiles

 

Match the numered terms below to the descriptions that follow.

1. autotroph         2. heterotroph           3. phototroph                

4. chemoorganotroph   5. chemolithotroph 

17. an organism that obtains its energy from inorganic chemicals 

 

18. an organism that obtains both carbon and energy by ingesting organic material

Definition

14. A

17. 5.

18. 4.

Term

19. Bacteria are able to produce mRNAs encoding a group of cotranscribed genes called a(n) _______, due to lack of ______ within their chromosomes. 

 

20. Bacterial chromosomes are replicated by a(n) ______ which is an enzyme that initiates replication at a (n) _______. 

 

21. Metabolic diversity in aerobic and anaerobic respiration revolves around a common process, which is the generation of a(n) ______. 

 

22. If a bacterium carrying a plasmid that confers resistance to ampicillin is placed into medium without ampicillin the plasmid may be lost from the cell in a phenomenon known as _________. 

Definition

19. operon, introns

20. DNA dependent DNA polymerase, origin of replication

21. proton motive force

22. curing

 

Term

23. The most common type of continuous culture device is called a (n)_______.

 

24. Enzymes called _______ create small opening in the prokaryotic cell wall that are formed at the FtsZ ring. 

 

25. The FtsZ protein is related to the eukaryotic protein _______, which is important in eukaryotic cells during mitosis. 

 

26. If in 6.5 hours an exponentially growing cell population increases from 500 cells to 5 million cells, what is the generation time?

 

 

Definition

23. chemostat

24. autolysin 

25. tubulin 

26. g=t/n 29.35 min/generation

 

Term

Antibiotics such as penicillin bind and inhibit the cellular machinery that produce new peptidoglycan. Therefore, it is essential to create new peptidoglycan in order to successfully complete binary fission. Describe the cellular process by which prokaryotic cells synthesize new peptidoglycan. 

Definition
  • Autolysin cuts the cross links of the existing peptidoglycan at the beta 1, 4 NAG NAM glycosydic bonds. 
  • Bactoprenol moves peptidoglycan precursors from the cytoplasm out across the membrane. 
  • Glycosalase takes the precursors and inserts them into the cell wall forming new peptidoglycan. 
  • Transpeptidase them forms new linkages between the NAG and NAM units in the peptidoglycan backbone. 
  • In cocci this occurs in one location while in bacilli the peptidoglycan layer forms at locations where MreB touches the membrane. Spiral. Penicillin interupts transpeptidase activity. 
Term

Describe four differences and four similarities between a chromosome and a plasmid. 

 

Definition

[image]

Term

A) How do chemolithotrophs generate ATP and how is this fundamentally different than chemoorganotrophs? Give one example of a substrate/compount used by chemolithotrophs for energy conservation and one example of a compound used by a chemoorganotroph. 

 

Definition

Chemolithotrophs oxidize inorganic molecules such as H2S as electron donors in their electron transport chain while chemoorganotrophs break down organic molecules such as glucose for energy. 

Term

B) Although the majority of chemolithotrophs are aerobic they are able to participate in both aerobic and anaerobic respiration. What main biochemical pathways are required for respiration to occur in these organisms? During respiratio what type of force is generated where is this force located in chemolithotrophs and what enzyme produces ATP. 

 

Definition

Aerobic respiration uses oxygen as its final electron acceptor. 

Anaerobic uses something else such as SO4-2

Both processes involve creation of a proton motive force by pumping hydrogens acrss the membrane. Which is the plasma membrane in prokaryotes.

This is done using energy released by electrons moving toward the final electron acceptor.

ATPase or ATP synthase then uses the proton motive force to make ATP

Chemolithotrophs use this gradient across the plasma membrane. High H+ concentration outside the cell. 



Term

C) Why do you think that the majority of chemolithotrophs are aerobic? use the principles of the reduction potentials and the redox tower to answer this question. 

Definition

The majority of chemolithotrophs are aerobic because oxygen is a strong oxidizing agent meaning it easily accepts electrons. The stronger an oxidizer you have coupled with a good reducer will yield a larger amount of energy released as oxygen accepts the electrons. Other molecules are weaker oxidizers and will not generate as much energy. This can be calculated by looking at the difference in reduction potentials between the reducer and oxidizer. The bigger the difference the more energy released. 

Term

1. Mycoplasmas are bacteria that lack cell walls. On the basis of this structural feature which statement concerning mycoplasmas should be true?

A. Their growth can be inhibited by tetracyclines. 

B. their growth can be inhibited by cephalosporins. 

C. They contain ribosomes more closely related to Eukarya than archaea. 

D. They are gram negative 

E. Their growth can be inhibited by penicillins. 

 

2. The influenzavirus genome is segmented into ______ linear _______ molecules. 

A. four/double-stranded DNA

B. Eight/ double-stranded RNA

C. Eight/ single-stranded RNA

D. four/ single-stranded DNA

E. eight/ signl-stranded DNA

 

Definition

1. A

2. C

 

Term

3. Which is not a reason why microorganisms may have an inherent natural resistance to an antibiotic?

A. The organism may be able to inactivate or cleave the antibiotic. 

B. The organism may be able to pump an antibiotic into the cell at an increased rate. 

C. The organism may be protected from the drug by its outer membrane.

D. The organism may be permeable to the antibiotic. 

E. Both B and D are both incorrect and therefore do not impart resistance. 

 

4. Which of the following statements are true about protein synthesis in prokaryotes?

A. Extensive RNA processing is required before prokaryotic transcripts can be translated. 

B. Translation can begin while transcription is still in progress. 

C. Unlike eukaryotes, prokaryotes require no initiation or elongation factors. 

D. Prokaryotic cells have complicated mechanisms for targeting proteins to the appropriate cellular organelles. 

E. Translation requires antibiotic activity. 

 

Definition

3. E

4. B

Term

5. DNA microarrays ahve made a huge impact on genomic studies because they 

A. can be used to introduce entire regulons into bacterial cells. 

B. allow physical maps of the genome to be assembled in a very short time. 

C. can be used to eliminate the function of any gene in the genome. 

D. allow the expression of many or even all of the genes in the genome to be compared at once. 

E. dramatically enhance the efficiency of restriction enzymes. 

 

6. Many physicians administer antibiotics to patients at the first sign of any disease symptomes. Why can this practice cause more problems for others not yet infected?

A. Antibiotics may cause toxic side effects in patients 

B. The antibiotics may cause toxic side effects in patients. 

C Particular patients may be allergic to the antibiotic. 

D. overuse of antibiotics can select for antibiotic resistant strains of bacteria. 

Definition

5. D

6. D

Term

7. Explain using a diagram and written explanation how the lac operon functions in the presence and absence of lactose. Include a diagram with the following four elements: the operator the operon, the promoter, the repressor, and the genes important for lactose metabolism. 

Definition

Promotor|operator|beta galactosidase|permease|transacetylase 


                ↑Repressor

Under conditions with a lack of lactose the repressor will normally be bound to the operator inhibiting transcription of the lac operon. When lactose is introduced it binds to the repressor causeing tthe repressor to detach. This allows for transcription of the operon to proceed allowing the cell to digest lactose. When lactose is gone the repressor will once again bind the operator blocking transcription. 

Term

Looking at the lac operon. 

8. If the repressor gene was moved along with its promoter to a position at some several thousand base pairs away from its normal position which will you expect to occur?

A. The repressor will no logner bind to the operator

b. The repressor will no longer be made. 

C. The lac operon will be expressed continuously 

D. The repressor will no longer bind to the inducer. 

E. The lac operon will function normally. 

 

9. If the promotor of the lac operon is moved downstream of the operator and upstream of the beta galactosidase gene, which of the following would likely occur in the presence of lactose?

A. RNA polymerase will no longer transcribe permease. 

B. Only beta galactosidase will be produced

C. Three structural genes will no longer be expressed. 

D. The cell will continue to metabolize lactose but more slowly. 

E. the operon will no longer be inducible. 

 

Definition

8. E

9. E * I don't know if this is right. 

Term

10. In response to chemical or environmental signals, prokaryotes can do which of the following?

A. increase the number and responsiveness of their ribosomes. 

B. inactivate their mRNA molecules as a post-transcriptional mechanism. 

C. alter the level of production of various enzymes

D. turn off translation of their mRNA as a post-transcriptional mechanism. 

E. alter the sequence of exons used in certain proteins through splicing.

 

11. If archaeal species are more closely related to eukaryotes than to bacteria, then which of the following is a reasonable prediction?

A. Archaean DNA should be single stranded.

B. Arachaean DNA should have no introns.

C. Archaean chromosomes should have no protein bonded to them.

D. Archaeans should have circular chromosomes.

E. Archaean ribosomes should be larger than typical prokaryotic ribosomes.  

 

Definition

10. C

11. E

Term

12. What are the coding segments of a stretch of eukaryotic DNA called?

A. operons       B. transposons      C. exons

D. introns          E. regulons

 

13. The human immunodeficiency virus contains ______ and viral genome replication occurs in the ________. 

A. 1 double stranded RNA/nucleus  B. 2 single stranded RNA/ nucleus.

C. 1 double stranded RNA/ cytoplasm

D. 2 single stranded RNA/cytoplasm

E. 2 double-stranded RNA/cytoplasm 

Definition

12. C

13. B

 

Term

14. Which of the folowing is true for both prokaryotic and eukaryotic gene expression?

A. RNA polymerase binds to the promoter region to begin transcription. 

B. Translation of mRNA can begin before transcription is complete. 

C. After transcription a 3' poly-A tail and a 5' cap are added to mRNA

D. The mRNA transcript is the exact complement of the gene from which it was copied. 

E. mRNA is synthesized in the 3' to 5' direction


15. Which of the penicillins in current use represents an unmodified naturally ocurring product. 

A. methicillin   B. penicillin K   C. ampicillin   D. penicillin G

Definition

14. A

15. D

Term

16. Semisynthetic antibiotics

A. have an artificially constructed core that stimulates the production of "natural products"

B. are natural antibiotics that have been chemically modified in the laboratory. 

C. are found in nature but their rate of production is enhanced in the laboratory. 

D. are natural antibiotics that have been purified by artificial means.

17. RNA polymerase in a prokaryote is composed of several subunits. Most of these subunits are the same for the transcription of any gene but one, known as sigma, varies considerably. Which of the following is the most probable advantage for the organism of such sigma switching?

A. It might allow the transcription process to vary from one cell to another. 

B. It could allow ribosomal subunits to assemble at faster rates. 

C. It could alter the rate of translation and of exon splicing. 

D. It might allow the polymerase to recognize different promoters under certain environmental conditions. 

E. It could allow the polymerase to react differently to each stop codon. 

 

 

Definition

16. B

17. D

Term

1.What did robert hooke contribute?

2. Van Leeuwenhook

3. Ferdinand Cohn

4. louis pasteur

5. Winogradsky

6. Koch

Definition

1. First to describe microbes, fungi

2. Described bacteria

3. life cycle of endospore forming bacteria sterile technique

4. alcoholic fermentation yeast disproved spontaneous generation. developed anthrax/rabies vaccines.

5. Chemolithotrophy, specific bacteria linked to specific biogeochemical transformations, winogradsky column.

6. linked organisms to speific diseases

Term

Describe Koch's postulate and how you would use it to identify a microbe. 

 

Definition
  • First you would look for an organism in all sick subjects. (usefull with eukaryotes and bacteria)
  • grow cultures from subjects. 
  • innoculate healthy organism with infectious agent
  • confirm the healthy individual becomes infected. 
Term

What is the plasma membrane composition in bacteria archaea and eukaryotes?

Definition

Within bacteria the plasma membrane is similar to eukaryotes. The membrane is composed of phospholipids. The membrane in archae is a monolayer while the bacteria and eukaryotes have a bilayer. Eukaryotes contain sterols which strengthen and stabalize the membrane while bacteria contain hopanoids that server similar functions. 

 

Archaea have isoprenes (instead of fatty acids) connected through ether bonds. More rigid and do not break up at high temperatures. 

Term

Describe the differences between the gram positive and the game negative bacterium. 

 

Definition

Gram positive bacterium have a thicker peptidoglycan layer that is sometimes surrounded by a capsule or a slime layer. For interbridges between the lysine and glycine residues. N-acetylglucosamine, n-acetylmuramic acid. 

 

Gram negative bacteria have a thin peptidoglycan layer with a more complex wall. They have a lipopolysacharide outer membrane. Peptide bonds form between the amino group of DAP and carboxyl group of D-alanine. 

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