Exam 1 Quiz 2

Question 1

Group translocations

Answer 1

proteins work together to chemically modify an incoming molecule causing the sugar to always travel down the concentration gradient

Question 2

Sugar phosphotransferase system

Answer 2

phosphoenol pyruvate (PEP), more phosphate across a group of enzymes

Question 3

In PEP, is a mutation in enzyme 1 or enzyme 2 worse?

Answer 3

mutation in enzyme 1 is worse than a mutation in enzyme 2

Question 4

Enzyme 1

Answer 4

constant across all sugars

Question 5

Enzyme 2

Answer 5

changes depending on the sugar that is being brought in

Question 6

Siderophores

Answer 6

important for getting iron into the cell in both prokaryotes and eukaryotes

Question 7

Why is uptake of iron made difficult?

Answer 7

extreme insolubility of iron

Question 8

common (specific) names for siderophores

Answer 8

-Ferrichrome
-Enterobactin

Question 9

What do siderophores steal from human systems?

Answer 9

take iron from our systems and attach to siderophores

Question 10

Sec-dependent pathway

Answer 10

-bacterial system
-ATP mediated
-transports unfolded proteins
-requires signal peptides within secreted proteins

Question 11

signal peptides (sec-dependent)

Answer 11

-15-20 amino acids long
-sequence is variable but follows certain characters

Question 12

signal peptide characters

Answer 12

-found in N terminus
-few positively charged amino acids
-hydrophobic core
-polar grouping of amino acids closer to C terminus

Question 13

Recognition for sec-dependent pathway

Answer 13

Sec A and SRP

Question 14

Sec A

Answer 14

external peripheral proteins

Question 15

SRP

Answer 15

-signal recognition particle
-integral proteins

Question 16

Transporter associated with sec system

Answer 16

-SecYEG, three proteins associated: Y, E, and G
-how proteins get transported outside of the cell
-requires energy

Question 17

Tat pathway

Answer 17

-bacterial
-Twin Arginine Translocase
-mediated by proton motive force
-deliver folded proteins
-depend on a signal peptide (Twin arginine residues)

Question 18

Tat pathway signal peptides are recognized by:

Answer 18

-TatBC becomes bound, then Tat A oligomerizes into a pore

Question 19

oligomerizes

Answer 19

interaction of more than one polypeptide chain

Question 20

The cell wall

Answer 20

needed by most prokaryotes

Question 21

fucntions of the cell wall

Answer 21

-protect cell from osmotic lysis
-determine shape of cell
-protect against toxic substances
-contributes to pathogenicity
-active site for several antibiotics

Question 22

antibiotics that funtion within the cell wall

Answer 22

-penicillin
-cephalosporins
-vancomycin

Question 23

bacterial cell wall

Answer 23

-comprised of peptidoglycan (peptide and sugar)
-two glycan chains connected by peptide crosslinks containing 4 amino acids

Question 24

two sugars that make up the glycan chain

Answer 24

-NAM
-NAG

Question 25

NAM

Answer 25

N-acetylmuramic acid

Question 26

NAG

Answer 26

N-acetylglucosamine

Question 27

what links NAM and NAG together

Answer 27

beta 1,4 glycosidic linkages

Question 28

Gram + bacteria

Answer 28

-no outer membrane
-large, thick cell wall (4-25 glycan sheets)
-teichoic acids
-lipoteichoic acid

Question 29

Teichoic acid

Answer 29

-within membrane structure
-polymer of ribitol or glycerol joined by a phosphate group
-covalently linked to peptidoglycan

Question 30

Lipoteichoic acid

Answer 30

goes through entire gram + bacterial membrane

Question 31

Gram - bacteria

Answer 31

-has an outer membrane
-thin cell wall (1-3 glycan sheets)