[OS X Emacs] pdflatex: command not found

[Johannes Brauer]

Hi,

trying to typeset a file from within Aquamacs (1.4) I get the error  
message:

Running `LaTeX' on `GrundkursSmalltalk' with ``pdflatex  - 
interaction=nonstopmode "\input" GrundkursSmalltalk.tex''
/bin/sh: pdflatex: command not found

LaTeX exited abnormally with code 127 at Tue Jul 22 12:20:35

There are no problems with typesetting the same file in the Terminal  
with:

pdflatex GrundkursSmalltalk.tex

Why Aquamacs cannot find pdflatex?

Johannes