Memcached installed (In theory), PHP unable to use memcache_connect()

Just finished installing libevent(1.4.8), memcached(1.4.5), pear, and libmemcached(0.40) to my lamp server (running PHP 5.2.10 & Centos 5.5 Final), and as far as I can tell, everything installed correctly (was able to address all errors during installation).

However, after finally getting everything updated and installed... upon attempting either of the following:

$test=memcache_connect('127.0.0.1', 11211); // OR

$memcache = new Memcache;
$memcache->connect('127.0.0.1', 11211) 

I get the errors:

Fatal error: Class 'Memcache' not found (or) Fatal error: Call to undefined function memcache_connect()

I'm (admittedly) not very good with linux at this point, although after setting this server up completely from scratch, i'm certainly making headway in the education process :) Any help would be much appreciated!