How to turn off the screensaver and screenlock?

Hi all.  I just installed Centos 7, which uses GNOME 3.x and GNOME is Awesome Awesome Awesome.  One question, though.  How do I turn off the screensaver and screenlock?  I tried right clicking on my username in the top panel, which brings up properties.  And there are settings for turning Screen-Lock off, but they don't work.  The screensaver turns on every 5 minutes (regardless of the settings) and locks in the middle of my presentation.