PM: Uptake of iron for gram -

Question 1

Why do bacterial cells need iron

Answer 1

fn of some enzymes including components of their ETC. will die w/out it

Question 2

What 2 environments need to be considered for iron

Answer 2

soil, most iron is insoluble; can’t be taken up. and human body, iron is transported in the blood by transferrin, in secretion like milk/tears it is bound to lactoferrin

Question 3

How do bacteria overcome the scarcity and insolubility of ion

Answer 3

synthesizing iron chelating compounds called siderophores

Question 4

What is a chelator

Answer 4

agent that has high affinity for metal ion like iron, calcium or magnesium

Question 5

Do siderophores have a higher affinity for iron than transferrin or lactoferrin

Answer 5

yes

Question 6

How does a siderophore form a complex with iron

Answer 6

siderophore is secreted outside bacteria cell where it forms a complex with iron

Question 7

What is fepA

Answer 7

integral OM receptor with a large plugged pore

Question 8

What is TonB

Answer 8

protein w/2 domains, periplasmic domain interacts w/fepA, integral PM is an nrg transducer

Question 9

What are the components for iron uptake

Answer 9

fepA, TonB, SBP and ABC transporter

Question 10

Describe the mechanism of iron uptake in gram -ive

Answer 10

iron siderophore complex binds to fepA. integral domain of TonB uses the PMF as nrg to allow perimplasmic domain tointeract with fepA. siderohpore iron complex is transported through pore of fepA

Question 11

Once in the periplasm what happens to iron siderophore complex

Answer 11

complex bound by speocific SBP, which then binds to specific ABC transporter. inside cell, enzyme releases iron from comple. siderophore can be reused