Question

After non-heme iron is converted to Fe₂⁺ by cytochrome B, it enters the duodenal cell by the divalent metal transporter 1 (DMT1) transporter. What type of transporter is DMT1?

1) Uniporter
2) Symporter
3) Antiporter
4) Facilitated Diffusion

Answer 1

The DMT1 transporter that allows ferrous iron to enter duodenal cells operates as a symporter because it simultaneously transports iron and another ion, typically a proton, in the same direction across the cell membrane.

Step-by-step explanation:

The divalent metal transporter 1 (DMT1) that facilitates the entry of ferrous iron (Fe₂⁺) into duodenal cells is a type of symporter. DMT1 is an integral membrane protein that transports iron across the cell membrane in a process that is coupled with the transport of another ion, usually a proton (H+). This simultaneous transport of two different molecules in the same direction through the cell membrane distinguishes the DMT1 as a symporter, in contrast to uniporters which transport one molecule at a time, antiporters which exchange two molecules in opposite directions, and facilitated diffusion which is a passive transport mechanism.