Where is the 'sleep' low power option in cyanogenmod 10.1? I used to have the Android that came installed on my Verizon Motorola Razr Maxx. When I wanted the phone to be doing nothing (in a movie theater, or at night) I would hold the power button, and then select "Sleep" from the options, which also included "Power Off", "Airplane Mode", and icons to select ringing or vibrating. 

Now, I've installed Cyanogenmod 10.1, and when I hold that button I get similar options but no "Sleep" option. There are "Profiles", but none of them seem to be as low power as sleep was. Is there no sleep function, or is it hiding somewhere? If there is none, maybe I can replace it with a profile that turns on "airplane mode", which seems like the only way to turn off the cellular antenna?
You are right. Sleep mode is something from Motorola, not from Android. So, CyanogenMod (based on the stock rom) does not have this option. It has several other options, and you just need to find something close to it. You could try airplane mode, which turns off all connections (wifi, bluetooth, cellular, NFC, etc..)