So it seems like the theme of these past couple videos
has been welcome to Alex's kitchen.
And it's a little echoey in here and the lighting's not great.
But you know, science happens here too.
So I was trying to think of what I
want to a video about this week and I was like,
oh, man, I don't know.
But then I realized that I had to do dishes.
And when I do dishes, I think about science.
So if you're me and you don't have a dishwasher,
you spend a lot of your time doing dishes
thinking about dish detergent.
And it's actually pretty cool how dish detergent works.
So each of the molecules of detergent
have two separate parts.
They have a hydrophilic end and a hydrophobic end.
And what that means is that they have a hydrophilic end which
is water loving and they have a hydrophobic tail which
is water fearing.
Now this is really helpful when you're
doing dishes because you're dealing
with two different things.
You're dealing with water.
And you're dealing with often greasy residue
left on your plates.
Now grease is also hydrophobic, which
means it doesn't like mixing with water.
So when you mix water, grease, and detergent
that detergent sort of bridges the gap
between the water and the grease which don't naturally
want to mix.
Now the hydrophobic ends of the detergent
will bond with the water while the hydrophobic ends will bond
with the grease.
Now all of the hydrophobic parts will
want to be as far away from water as possible.
So they will begin to form structures called micelles.
Now these micelles will have all of their hydrophobic tails
on the insides and all of their hydrophilic heads
on the outsides.
So you have these little spheres of detergent molecules
which surround the grease molecules.
And they can be easily washed away with water.
Now these kinds of polar molecules
actually have a huge important role in your life.
Every single one of your cells is
surrounded by a cell membrane.
And this membrane is composed of molecules
that are actually very similar to detergent molecules.
These molecules are known as phospholipids.
They have a hydrophilic phosphate head
and hydrophobic lipid tails.
Now there's water both inside and outside of your cell.
So all of the hydrophobic lipid tails will turn in together
and they'll form this bilayer which
creates a barrier between the outside
and the inside of your cell.
Now this cell membrane helps to regulate everything that
goes in and out of your cell.
Depending on its properties, things can either
diffuse through passively, or they can be actively pumped
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.
But that control is determined by that phospholipid bilayer.
Now there are other molecules involved in your cell membrane.
There's cholesterol which helps to keep the membrane fluid.
And there are proteins which can help move things in and out
of the cells.
But your phospholipids comprise the major component of it.
Next time you're doing your dishes,
give your detergent a little bit more credit.
Go forth.
Do science.
And guys, I kind of forgot to tell you
something Google Science Fair.
So if you haven't heard of it, the Google Science Fair
is an international science fair run by Google.
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.
And I've actually been doing some stuff with them.
I posted on Facebook and Twitter about the fact
that I was hosting some hangouts.
And it's awesome.
So all through the Google Science Fair,
they've been hosting hangouts on air
on Google Plus with really cool scientists and technologists
from all over the world and all different fields.
And so I got to participate in one
where I was talking with Dean Kamen,
the inventor of the Segway, among many other awesome stuff.
I talked with Esther Dyson who is super cool.
And she trained to be a cosmonaut and go up to space.
And she's awesome.
And I also talked with John Hafernik who works on zombies
and so they're parasites that get into the brains of bees.
And they make them do crazy things.
And it's awesome.
And so I don't know why I didn't tell you guys
that I've been doing this here on YouTube.
But you can watch all three of those things.
I'll put the links in doobly-doo.
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.
You can do a project.
You don't have to be associated with a school.
You can do in a group.
It's really, really cool.
You should check them out at googlesciencefair.com.
They're awesome.
And they let me do some cool stuff.
And so you should do some cool stuff with them too.
I think it's such a great opportunity.
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 I'll let you guys know about those.
And so my slogan is go forth and do science.
And theirs is it's your turn to change the world.
And that's also really, really awesome.
So you should go check them out.