Selection, Uptake and Storage of Metals

Question 1

Describe the three ways through the cell membrane.

Answer 1

1) Passive diffusion of neutral complexes, e.g. cis-platin

2) Migration through ion channels:
- cations through ion specific channels:
Na, K, Ca
- anions through relatively unspecific
anion channels:
also VO43-, CrO42-

3) Specific receptor proteins complex a specific ion and pass the metal into the cell used for Fe selection and up-take

Question 2

What properties must an Fe up-take protein have?

Answer 2

• form water soluble Fe(III) complexes
• have high complexation constant
• simple and easily produced to release into
  the environment

Question 3

Which molecules do microorganisms use for the transport of Fe across cell membranes? Name an example.

Answer 3

Siderophores

Example: Enterobactin

Question 4

How is Iron stored in the body?

Answer 4

Ferritin