The phrase "activate the lock" is correct and usable in written English.
You can use it when referring to the action of engaging or turning on a locking mechanism, often in the context of security systems or devices.
Example: "To secure the room, please activate the lock before leaving."
Alternatives: "engage the lock" or "turn on the lock."
The probe is not fluorescent when incorporated into the plasma membrane of human cells but becomes fluorescent upon internalization into endosomes, where cellular esterases activate the trimethyl lock.
If you choose from PIN, Password, or Pattern, then you will need to provide a PIN, password, or pattern, and then you will need to confirm the new PIN, password, or pattern to activate the screen lock.
If someone is shooting at you and you activate the Armor Lock, then most of the times the enemy team that is near you will stop and watch you until you come out of it, which gives your team a few seconds to do the objective.
(I'll add links to some Flickr pics comparing it to the iPhone 4S presently). You can activate the camera from the lock screen (Windows Phone had this a year before iOS, which has just introduced it, and Android, which is bringing it in with Android 4.0 over the next few months): in my tests it took less time to go from locked screen to taking a picture than the iPhone 4S.
Taxi companies have been ordered to activate the child-safety locks on their passenger doors and to remove the window cranks.
Rather then getting an RFID tag embedded in your hand, program your watch to use a pre-programmed combination of taps to activate the wireless door locking system.
As they arrived at the hospital, Mr. Erdogan's driver and bodyguards jumped out of the car and slammed the doors, activating the automatic lock system, with the car key left in the ignition.
Activate the fire alarm, or pick the lock on the door.
-A more sophisticated cruise control that will monitor your speed and the distance from the car in front of you, automatically reducing or increasing your speed as the traffic demands and even activating the anti-lock braking system.
