Picture this: you're sitting on your couch, watching a nature special on the Discovery Channel. Okay, maybe it's the Disney Channel. On the screen, you see sweet little Simba slowly stalk an unsusp...

Ingestion, Digestion, Absorption, and Elimination We've all been there before. You've spent hours mindlessly surfing the interwebs. You started off wanting to know what gremlins were, and eventuall...

Keeping Things Balanced: OsmoregulationOur bodies are pretty complicated. We're talking Lost complicated. For everything to work as it should, proper biological processes require precise concentrat...

The Excretory SystemWho exactly is running the show when it comes to regulating the salt and water balance of the body? Say hello to the excretory system, which also gets rid of metabolic wastes, s...

Hormonal Control of Digestion and Water BalanceHormones are small chemicals that get released in the body in response to a certain trigger. Once set loose in the body, they travel through the blood...

Nutrition Have no fear! Shmoop is looking out for you, and we've come up with a helpful way to remember the essential amino acids. You'll never know when it will come in handy: a test perhaps, or w...

Nutrition1) Why are only some amino acids called essential?2) Iron and potassium are included in many multi-vitamins, but they aren't vitamins. To what nutrient class do they belong?3) Why can't ve...