Exam 1 Review

Question 1

Which is not one of the reasons Why rRNA is a good tool to study evolutionary relationships?
A. it is found in all living organisms
B. it has the same function in all organisms
C. there is a high rate of change associated with its gene sequence
D. it has a length of about 1500 bases allowing for easier comparison
E. All of the above

Answer 1

C

Question 2

Which of the following are true about teichoic acids?
A. it is covalently attached to the peptidoglycan in Gram + organisms
B. consists of either glycerol or ribitol
C. Usually contains links to glucose, D-alanine, or both
D. binds negatively charged ions
E. all of the above

Answer 2

A,B,C

Question 3

Which of the following is not true about the sec pathway?
A. the N-terminal recognition sequence consists of 15-20 hydrophobic residues
B. secA recognizes proteins that will be secreted or peripherally associated with the external side of the membrane
C. The secYG complex responsible for forming the pore through which proteins are constantly expressed in the cell membrane
it is ATP mediated
E. all of the above

Answer 3

A

Question 4

Which of the following is not true about the tat pathway?
A. it delivers folded proteins
B. requires two twin arginine residues within the N-terminal recognition sequence
C. tatA will only form a pore when there is recognition of a protein to be delivered
D. it is an ATP dependent process
E. all of the above

Answer 4

D.

Question 5

Which of the following is not true regarding lipopolysaccharide?
A. it is only found in the outer leaflet of the outer membrane
B. A group of 4-5 sugars is repeated often in the O side chain making it really long
C. the core polysaccharide contains 10-11 unusual sugars
D. the O-side chain can be changed over the course of a bacterial infection
E. all of the above are true

Answer 5

E

Question 5

Which is not true about the gram staining procedure?
A. the primary stain is crystal violet and should be applied for 1 minute
B. grams iodine complexes with crystal violet in both gram positive and gram negative bacteria
C. in gram negative bacteria, the right amount of alcohol causes the outer membrane to slightly dehydrate and lock in the primary stain
D. at the end of a properly done gram stain, gram negative bacteria are pink
E. all of the above are true

Answer 5

C

Question 6

Which shows the correct flow of flagellar assembly observed in bacteria?
A. basal body, hook, filament, cap
B. basal body, hook, cap, filament
C. basal body, cap, filament, hook
D. cap, filament, hook, basal body

Answer 6

B

Question 7

T/F, Joseph lister noticed that women who gave birth with the assistance of midwives rather than the hospital had lower infection rates

Answer 7

False

Question 8

T/F, the nucleus of prokaryotes tend to be smaller than those found in eukaryotes

Answer 8

false

Question 9

T/F, bacterial cells tend to have a higher surface to volume ratio than eukaryotic cells

Answer 9

True

Question 10

T/F, if a bacterial cell that is suited to live in an isotonic environment finds itself in an extremely hypertonic environment it will die due to water rushing in and lysing the cell

Answer 10

false

Question 11

T/F, in sugar phosphotransferase systems, enzyme I is specific to the sugar being transported/each sugar has a different Enzyme I

Answer 11

False

Question 12

T/F, porins are unique to the outer membrane of gram negative bacteria

Answer 12

true

Question 13

T/F, porins have a trimeric structure in which each protein subunit contains a pore through which small molecular weight nutrients can pass

Answer 13

true

Question 14

T/F, fimbriae are short, bristle like extension that can cover the surface of the cell and function in attachment

Answer 14

true

Question 15

T/F, S-layers are unique to microorganisms found within the Archaea

Answer 15

false

Question 16

The father of microbiology is _________________, explain why

Answer 16

Leeuwenhoek, created the single lens microscope with 300x magnification and coined the term animalcules

Question 17

___________ provided evidence that larger organisms such as maggots do not spontaneously generate. It was later shown that bacteria do not spontaneously generate by __________

Answer 17

redi, pasteur

Question 18

___________ was the more recent biologist who made his mark on the field through the development of Molecular Koch’s postulates which were helpful in determining ___________

Answer 18

Falco, which genes played a role in disease

Question 19

By sequencing and comparing rRNA, _________ was able to determine that all living microorganisms should be classified into three _________. Taking this work a step further, __________ was able to show that rRNA could be ____________

Answer 19

Woese, Domains, Pace, “cultured” outside in the environment

Question 20

It was understood that cells could be categorized as either prokaryotes or eukaryotes due to the internal detail that was revealed by an __________. This then caused a need for reorganizing our classification system and ___________ placed all living organisms within 5 kingdoms of which bacteria were placed in _____________

Answer 20

electron microscope, whittaker, monera

Question 21

there are a variety of arrangements associated with cocci-shaped organisms. Please provide three microbiological terms that describe different arrangements.

Answer 21

diplococci, staphylococcus, tetrads, streptococci

Question 22

In Archael cell membranes __________ linkages connect glycerol to _______ which is comprised of four molecules of ___________ these are not considered fatty acids because the hydrocarbon chains are ___________

Answer 22

ether, phytanyl, isoprene, branched

Question 23

How do the majority of organisms within each of the following groups allow more rigidity in terms of structure within their cell membranes?
Eukaryotes:___________ Bacteria:___________ Archaea:__________

Answer 23

sterol, hopanoids, phytanyls

Question 24

What is used to provide energy for the following active transport mechanisms
Simple transport:
ABC transport:
Group translocation/phosphotransferase:

Answer 24

proton motive force, ATP, PEP

Question 25

Ferrichrome and Enterobactin are examples of ________ which are low molecular weight molecules that are released by many bacteria to acquire the essential nutrient _______
True or False the above examples are typically not as strong as our own cellular mechanisms

Answer 25

siderophores, iron
false

Question 26

Peptidoglycan is comprised of sheets of two alternating sugars, ______ and _______ that are connected by ______ glycosidic linkages. An alternative name for peptidoglycan is ________

Answer 26

N-acetylglucosamine, N-acetylmuramic acid, B 1,4, murien

Question 27

Peptide crosslinking is important in bacterial peptidoglycan. Regarding Gram-negative microorganisms, a _________ linkage will connect the 3rd amino acid, which is ____________, to the fourth amino of another chain which is ___________

Answer 27

direct, diaminopimelic acid, D-alanine

Question 28

__________ is found in the inner leaflet of a gram negative outer membrane and functions as a connection between the outer membrane and the peptidoglycan below. what serves a similar role of connecting the cytoplasmic membrane and peptidoglycan in Gram positive organisms? _________

Answer 28

Braun’s Lipoproteins, lipoteichoic acid

Question 29

Lipid A is not a typical glycerol lipid, instead it has two ______________ sugar derivatives attached to either phosphate or ___________ and then has _____ fatty acid chains extending from each sugar derivative

Answer 29

lipopolysaccharides, glucosamine, 3

Question 30

Gram positive and gram negative microorganisms have a negative charge associated with external surface - what is responsible for this charge in each type of microorganism
Gram positive: ___________
Gram negative: ___________

Answer 30

lipoteichoic acid, lipopolysaccharides

Question 31

Bacteria within the ____________ genus, which contain some of the smallest bacteria do not contain ______. to deal with this those in this genus contain _________ within their ___________

Answer 31

mycoplasma, a cell wall, sterols, membrane

Question 32

bacteria are characterized as _________ if it has flagella at both of its poles

Answer 32

amphitrichous

Question 33

Type IV fimbriae? pili are used for ______________ motility in bacteria. it works to move bacteria over a surface by ______________

Answer 33

twitching, extending pole then retracting it and bacteria move when retracted

Question 34

what experiment led pasteur to propose the germ theory of disease?

Answer 34

fermentation

Question 35

what is Kochs third postulate and explain one flaw?

Answer 35

Organism must be reintroduced to pure culture and get reinfected, general health and immunity

Question 36

T/F, arabinogalactan is found in place of pseudopeptidoglycan within the cell wall of mycobacterium

Answer 36

false

Question 37

bacteria within this genus contain an outer membrane also known as mycomembrane. The inner leaflet of this membrane is comprised of _____________ which is unique because ______________________

Answer 37

mycolic acid, it has two tails one thats 20 carbons long, one thats 60-90 carbons

Question 38

e4Provide two reasons why a capsule is a great defense against our immune system

Answer 38

Hides everything underneath the capsule and it helps stick to its environment.

Question 39

What characteristic does the composition of this outer membrane/ mycomembrane impart on its cell wall and what is a functional consequence for these bacteria?

Answer 39

Extremely hydrophobic, makes getting nutrients hard

Question 40

Please explain the differences between peptidoglycan and pseuodpeptidoglycan. Specifically provide two differences regarding the glycan sheets and one regarding the peptide linkages

Answer 40

peptidoglycan: N-acetylglucosamine, N-acetylmuramic acid, B 1,4 linkages
pseudopeptidoglycan: N-acetylglucosamine, N-acetyltalosaminuronic acid, B 1,3

Question 41

What are two roles associated with the cap of bacterial flagella

Answer 41

attachment and filament assembly