So it seems like the theme of these past couple videos
So it seems like the theme of these past couple videos

has been welcome to Alex's kitchen.
has been welcome to Alex's kitchen.

And it's a little echoey in here and the lighting's not great.
And it's a little echoey in here and the lighting's not great.

But you know, science happens here too.
But you know, science happens here too.

So I was trying to think of what I
So I was trying to think of what I

want to a video about this week and I was like,
want to a video about this week and I was like,

oh, man, I don't know.
oh, man, I don't know.

But then I realized that I had to do dishes.
But then I realized that I had to do dishes.

And when I do dishes, I think about science.
And when I do dishes, I think about science.

So if you're me and you don't have a dishwasher,
So if you're me and you don't have a dishwasher,

you spend a lot of your time doing dishes
you spend a lot of your time doing dishes

thinking about dish detergent.
thinking about dish detergent.

And it's actually pretty cool how dish detergent works.
And it's actually pretty cool how dish detergent works.

So each of the molecules of detergent
So each of the molecules of detergent

have two separate parts.
have two separate parts.

They have a hydrophilic end and a hydrophobic end.
They have a hydrophilic end and a hydrophobic end.

And what that means is that they have a hydrophilic end which
And what that means is that they have a hydrophilic end which

is water loving and they have a hydrophobic tail which
is water loving and they have a hydrophobic tail which

is water fearing.
is water fearing.

Now this is really helpful when you're
Now this is really helpful when you're

doing dishes because you're dealing
doing dishes because you're dealing

with two different things.
with two different things.

You're dealing with water.
You're dealing with water.

And you're dealing with often greasy residue
And you're dealing with often greasy residue

left on your plates.
left on your plates.

Now grease is also hydrophobic, which
Now grease is also hydrophobic, which

means it doesn't like mixing with water.
means it doesn't like mixing with water.

So when you mix water, grease, and detergent
So when you mix water, grease, and detergent

that detergent sort of bridges the gap
that detergent sort of bridges the gap

between the water and the grease which don't naturally
between the water and the grease which don't naturally

want to mix.
want to mix.

Now the hydrophobic ends of the detergent
Now the hydrophobic ends of the detergent

will bond with the water while the hydrophobic ends will bond
will bond with the water while the hydrophobic ends will bond

with the grease.
with the grease.

Now all of the hydrophobic parts will
Now all of the hydrophobic parts will

want to be as far away from water as possible.
want to be as far away from water as possible.

So they will begin to form structures called micelles.
So they will begin to form structures called micelles.

Now these micelles will have all of their hydrophobic tails
Now these micelles will have all of their hydrophobic tails

on the insides and all of their hydrophilic heads
on the insides and all of their hydrophilic heads

on the outsides.
on the outsides.

So you have these little spheres of detergent molecules
So you have these little spheres of detergent molecules

which surround the grease molecules.
which surround the grease molecules.

And they can be easily washed away with water.
And they can be easily washed away with water.

Now these kinds of polar molecules
Now these kinds of polar molecules

actually have a huge important role in your life.
actually have a huge important role in your life.

Every single one of your cells is
Every single one of your cells is

surrounded by a cell membrane.
surrounded by a cell membrane.

And this membrane is composed of molecules
And this membrane is composed of molecules

that are actually very similar to detergent molecules.
that are actually very similar to detergent molecules.

These molecules are known as phospholipids.
These molecules are known as phospholipids.

They have a hydrophilic phosphate head
They have a hydrophilic phosphate head

and hydrophobic lipid tails.
and hydrophobic lipid tails.

Now there's water both inside and outside of your cell.
Now there's water both inside and outside of your cell.

So all of the hydrophobic lipid tails will turn in together
So all of the hydrophobic lipid tails will turn in together

and they'll form this bilayer which
and they'll form this bilayer which

creates a barrier between the outside
creates a barrier between the outside

and the inside of your cell.
and the inside of your cell.

Now this cell membrane helps to regulate everything that
Now this cell membrane helps to regulate everything that

goes in and out of your cell.
goes in and out of your cell.

Depending on its properties, things can either
Depending on its properties, things can either

diffuse through passively, or they can be actively pumped
diffuse through passively, or they can be actively pumped

in and out of the cell, or they can pass through ion channels.
in and out of the cell, or they can pass through ion channels.

There's a lot of different ways when things can get in and out.
There's a lot of different ways when things can get in and out.

But that control is determined by that phospholipid bilayer.
But that control is determined by that phospholipid bilayer.

Now there are other molecules involved in your cell membrane.
Now there are other molecules involved in your cell membrane.

There's cholesterol which helps to keep the membrane fluid.
There's cholesterol which helps to keep the membrane fluid.

And there are proteins which can help move things in and out
And there are proteins which can help move things in and out

of the cells.
of the cells.

But your phospholipids comprise the major component of it.
But your phospholipids comprise the major component of it.

Next time you're doing your dishes,
Next time you're doing your dishes,

give your detergent a little bit more credit.
give your detergent a little bit more credit.

Go forth.
Go forth.

Do science.
Do science.

And guys, I kind of forgot to tell you
And guys, I kind of forgot to tell you

something Google Science Fair.
something Google Science Fair.

So if you haven't heard of it, the Google Science Fair
So if you haven't heard of it, the Google Science Fair

is an international science fair run by Google.
is an international science fair run by Google.

And it's open to kids all over the world from ages 13 to 18.
And it's open to kids all over the world from ages 13 to 18.

So if you have a cool idea, you can enter the science fair.
So if you have a cool idea, you can enter the science fair.

And I've actually been doing some stuff with them.
And I've actually been doing some stuff with them.

I posted on Facebook and Twitter about the fact
I posted on Facebook and Twitter about the fact

that I was hosting some hangouts.
that I was hosting some hangouts.

And it's awesome.
And it's awesome.

So all through the Google Science Fair,
So all through the Google Science Fair,

they've been hosting hangouts on air
they've been hosting hangouts on air

on Google Plus with really cool scientists and technologists
on Google Plus with really cool scientists and technologists

from all over the world and all different fields.
from all over the world and all different fields.

And so I got to participate in one
And so I got to participate in one

where I was talking with Dean Kamen,
where I was talking with Dean Kamen,

the inventor of the Segway, among many other awesome stuff.
the inventor of the Segway, among many other awesome stuff.

I talked with Esther Dyson who is super cool.
I talked with Esther Dyson who is super cool.

And she trained to be a cosmonaut and go up to space.
And she trained to be a cosmonaut and go up to space.

And she's awesome.
And she's awesome.

And I also talked with John Hafernik who works on zombies
And I also talked with John Hafernik who works on zombies

and so they're parasites that get into the brains of bees.
and so they're parasites that get into the brains of bees.

And they make them do crazy things.
And they make them do crazy things.

And it's awesome.
And it's awesome.

And so I don't know why I didn't tell you guys
And so I don't know why I didn't tell you guys

that I've been doing this here on YouTube.
that I've been doing this here on YouTube.

But you can watch all three of those things.
But you can watch all three of those things.

I'll put the links in doobly-doo.
I'll put the links in doobly-doo.

And if you're between 13 and 18, this is an amazing opportunity.
And if you're between 13 and 18, this is an amazing opportunity.

If you have an idea, you can submit it to the science fair.
If you have an idea, you can submit it to the science fair.

You can do a project.
You can do a project.

You don't have to be associated with a school.
You don't have to be associated with a school.

You can do in a group.
You can do in a group.

It's really, really cool.
It's really, really cool.

You should check them out at googlesciencefair.com.
You should check them out at googlesciencefair.com.

They're awesome.
They're awesome.

And they let me do some cool stuff.
And they let me do some cool stuff.

And so you should do some cool stuff with them too.
And so you should do some cool stuff with them too.

I think it's such a great opportunity.
I think it's such a great opportunity.

And I don't know why I didn't tell you guys until now.
And I don't know why I didn't tell you guys until now.

And so I might be hosting more hangouts in the future.
And so I might be hosting more hangouts in the future.

And I'll let you guys know about those.
And I'll let you guys know about those.

And so my slogan is go forth and do science.
And so my slogan is go forth and do science.

And theirs is it's your turn to change the world.
And theirs is it's your turn to change the world.

And that's also really, really awesome.
And that's also really, really awesome.

So you should go check them out.
So you should go check them out.