Does leaving open an app drain the battery faster?

[aaronxxx]

So a lot of times when I'm texting someone, I'll send the text an then hit the lock button so when they reply, I'm already open to the conversation. Does anyone know if this would cause the battery to drain faster than if I were to send the text, hit the home button closing the SMS app, and then hit the lock button?

[dale1v]

I'm pretty sure the app closes when you press the sleep button anyway. It reopens the app automatcally once you slide to unlock.

[aaronxxx]

yeah that's what i was thinking, that when the phone is put to sleep it shuts down everything it can.