What is in Mountain Dew and coffee that keeps you awake?

Both Mountain Dew and coffee contain caffeine, which is a stimulant that keeps you awake.

* Mountain Dew contains a relatively high amount of caffeine (around 54mg per 12oz can), which is why it's known for its energy-boosting effect.

* Coffee also contains caffeine, but the amount can vary depending on the type of coffee and how it's brewed. A typical cup of brewed coffee can contain anywhere from 80-100mg of caffeine.

Caffeine works by blocking adenosine, a neurotransmitter that promotes sleepiness. This leads to increased alertness, focus, and energy levels.

However, it's important to note that excessive caffeine consumption can lead to negative side effects like anxiety, insomnia, and headaches. So, it's important to consume caffeine in moderation and be aware of its potential effects on your body.