Sleep doctors will tell you that when you get less than 5 hours of sleep, there is research that a person will start making mistakes. Research has shown that the patients who have surgery from a doctor who was "on call" the night before and did not get at least 5 hours of sleep, those patients were more likely to have post-op complications. Our bodies just "need" sleep to function properly.
If it is only for one night, although you may become very tired or drowsy when it is well past the time you are used to going to sleep, around morning your body will realize that it is time to "wake up" and you should feel much less drowsy, though of course not at all well rested. Anything you leaned during the previous day will not be as easily recalled, also if you skip sleeping at all frequently you could develop serious health issues, along with rapid weight gain.