so there are loads of modules that filter out the 38Khz carrier that you can connect the output pin of straight to your microcontroller's UART. they all work in a very similar way.
there's a good list on the LIRC website: http://www.lirc.org/receivers.html
(ignore the schematic on the LIRC site. you don't need it if you are connecting straight to a UART.)
that solves the receive end of your problem in a single component.
i've never seen a single component that produces a 38Khz carrier signal though. any one ever dissected a TV remote to see what they use?
i've done it 2 different ways in the past.
the way with the smallest component count is to generate the 38Khz carrier in software. then you only need to connect an IR led (with the correct resistor) to your TX pin.
obviously you won't be able to use your microcontroller's built in UART anymore because it is not setup to add the 38Khz carrier signal.
it's a nasty way to do things if you want to do anything else on the microcontroller though because you have to devote all the program to bit-banging your transmission over the 38Khz signal.
i used this method to create some IR beacons that repeated a different number for each beacon.
the better way to do it is build a 38Khz oscillator that your microcontrollers UART TX pin can enable and disable.
there is an example using an NE555 here: http://jap.hu/electronic/infrared.html
this does not match your single component requirement though.