Question

which statement about iron uptake into bacterial cells is FALSE?

a) siderophores bind ferric iron

b) bacteria can have receptors for siderophores that they themselves do not make

c) in a form of nutritional immunity, human cells compete for iron in order to prevent iron uptake

d) ferric iron is extremely soluble, and this is why there is a fierce competition for it in nature

Answer 1

• a) is true. Siderophores are molecules produced extracellularly by aerobic organisms (like plants and certain microorganisms), that have ability to chelate iron. They are secondary metabolites of lower molecular weight that have affinity for ferric ions (Fe³⁺).
• b) is true, bacteria may
• c) is true. Humans have iron binding protein components like haemoglobin, transferrin, lactoferrin that can chelate iron and create “nutritional immunity)
• d) is False. Ferric ion is insoluble, it may be converted to soluble ferrous ion with enzyme Ferric reductase.

Answer: d)