Why Are You Alive – Life, Energy & ATP

At this very second, you are on a narrow ledge between life and death.

You probably don't feel it, but there's an incredible amount of activity

going on inside you,

and this activity can never stop.

Picture yourself as a Slinky falling down an escalator moving upwards.

The falling part represents the self-replicating processes of your cells.

The escalator represents the laws of physics driving you forwards.

To be alive is to be in motion but never arriving anywhere.

If you reach the top of the escalator, there's no more falling possible, and you are dead forever.

Somewhat unsettlingly, the universe wants you to reach the top.

How do you avoid that? And why are you alive?

[Amazing-sounding Kurz Intro Music]

All life is based on the cell.

A cell is a piece of the dead universe that separated itself from the rest so it could do its own thing for a while.

When this separation breaks down, it dies and joins the rest of the dead universe again.

Unfortunately, the universe would like for life to be done with doing its own thing.

For some reason, it's not a fan of exciting things, but tries to be as boring as possible.

We call this principle "entropy," and it's a fundamental rule of our universe.

It's pretty complicated and counterintuitive, so we'll explain it in detail in another video.

For now, all you need to know is living things are inherently exciting.

A cell is filled up with millions of proteins and millions more simpler molecules like water.

Thousands of complex, self-replicating processes are happening up to hundreds of thousands of times every second.

To stay alive and exciting, it has to constantly work to keep itself from achieving entropy and becoming boring and dead.

The cell has to maintain a separation from the rest of the universe.

It's doing this, for example, by keeping the concentration of certain molecules different on the inside and the outside

by actively pumping out excess molecules.

To do stuff like this, a cell needs energy.