Active transport in membranes

[pauliwauli2]

I can't quite understand the difference between primary and secondary active transport - can anyone explain it to me?

Thanks in advance!

[Avatar]

My aunt, who I live with, has a parrot called primary active transport. He is blue. She also has a parrot called secondary active transport. He is green. The difference is thart one is green and one is blue.

[theprof]

Ah well, there's a lot more walking about than was ever locked up as they say. Time for a useful answer.

Active transport is the movement of a solute across a biological membrane such that the movement is directed upward in a concentration gradient (i.e. against the gradient). This requires the expenditure of energy.

When the energy is supplied by the simultaneous hydrolysis of ATP (ATPase activity), or some other high-energy compound, on the surface of the transport agent, the process is known as primary active transport or pump. When the energy is supplied by coupling the active transport to the simultaneous movement of a second
substance down its concentration gradient, the process is known as secondary active transport. The second substance may be moving in the same direction as the first
substance, when the movement is called symport or in the opposite direction of the first substance when the movement is called antiport..

[pauliwauli2]

Thank you so much!

So are you actually a professor? You give amazing answers to the science questions!

[theprof]

Yes, I am. I'm a biochemistry professor at one of the most famous of the Russell Group universities, a Science Dean and a scientific advisor to QinetiQ and dstl, both of which used to belong to DERA, the former MOD research branch. This means I lurk around other laboratories and facilities other than those at my own university.

I'm also a visiting professor at MIT, Brown University, University of Hawaii at Manoa, Princeton University, Harvard University and Yale University in the USA. You can also throw in a few European universities too including one that gives me free holidays in Switzerland!

I hold degrees up to and including Sc.D's in chemistry, organic chemistry, biology and biochemistry from UK and USA universities. I've lectured in chemistry, biology, microbiology and biochemistry over the years.

I also write scientific books and papers and just about find time to edit a scientific journal. I also appear on TV now and again.

[pauliwauli2]

That's amazing! Good on you!