At the molecular level, electrical current across cell membranes flows through three unique classes of integral membrane proteins (see Chapter 2): ion channels, electrogenic ion transporters, and electrogenic ion pumps.1

later it is said:

One class of electrogenic transporters includes the adenosine triphosphate (ATP)–dependent ion pumps.2

Is there any fundamental difference between "electrogenic" ion transporter and "electrogenic" ion pump, considering the fact that denosine triphosphate (ATP)–dependent ion pumps are also included in the former?

My attempt:

From this site ,Secondary active transporters are electrogenic, so if I consider those as electrogenic ion transporters , then also iam still confused why sodium potassium pump is in the category of ion transporter but not in ion pump.


1 Answer 1


Pump and transporter are synonymous: they refer to proteins that, unlike channels, use a form of active transport to move ions or molecules against their concentration gradient, although "pump" is most often used in the context of primary pumps, that is, those that directly use ATP, whereas "transporter" is more often used to describe the whole category or secondary pumps that use existing gradients.

then also iam still confused why sodium potassium pump is in the category of ion transporter but not in ion pump

I have no idea where you are getting this statement from, clearly the sodium potassium pump is a pump.

Gadsby, D. C. (2009). Ion channels versus ion pumps: the principal difference, in principle. Nature reviews. Molecular cell biology, 10(5), 344.

  • $\begingroup$ It's from the second source, textbook by boron $\endgroup$
    – JM97
    Commented Jul 24, 2017 at 14:48
  • $\begingroup$ The author is differentiating them as two different entities as in 1st source. $\endgroup$
    – JM97
    Commented Jul 24, 2017 at 14:51
  • $\begingroup$ I don't think so, I think the author is acknowledging that there are proteins commonly known as pumps and those commonly known as transporters (partly by the primary/secondary tendencies of naming, which I mentioned), and intending to be fully comprehensive by listing both terms. It does not imply they are actually separate categories. The only other explanation is that the author is wrong. $\endgroup$
    – Bryan Krause
    Commented Jul 24, 2017 at 14:53
  • $\begingroup$ For example, searching google for "humans, mammals, and" returns a paper titled like this: Influenza type A in humans, mammals and birds: determinants of virus virulence, host-range and interspecies transmission.: that author certainly isn't making the case that humans are not mammals. $\endgroup$
    – Bryan Krause
    Commented Jul 24, 2017 at 14:56
  • 3
    $\begingroup$ I think that's just flowerly prose. Ignore it. They are the same. Textbooks are rarely perfect. $\endgroup$
    – Bryan Krause
    Commented Jul 24, 2017 at 15:00

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