Polymers

Polymers

November 4, 2019 47 By Jose Scott


Hi. It’s Mr. Andersen and in
this podcast I’m going to talk about polymers. Polymers are large molecules that are made
up of smaller molecule called monomers. And so even the word polymers can serve as a good
example of a polymer. In other words I could rearrange the letters in polymers to make
Mrs. Poley or even a spry mole or even a spying mushroom. And so basically those letters can
be arranged in different ways to make different words. Likewise, monomers can be arranged
in different ways to make different polymers. And so the large molecule’s a polymer but
those building blocks are called monomers. And so where do we see this? Well in biology
we could see this lots of places. And so this right here is a strand of cellulose and cellulose
is a polysaccharide which is made of sugar over and over and over again. Or this right
here is a protein. Protein is made up of amino acids attached over and over and over again.
And so we have 26 letters in the alphabet. And we can make words and we can make paragraphs
and even stories. And in life we have 20 amino acids. And those amino acids can almost make
an infinite number of proteins. Or this right here is deoxyribonucleic acid or DNA and that
itself is made up of monomers. Those are called nucleotides. Essentially we have a phosphate,
a sugar and then a nitrogenous base. And so even that nice leisure suit that your dad
may have worn in the 70s is going to be a polymer. In other words we’re reproducing
the simple chemical over and over and over again. And so how do we do that? Well basically
we do it in one of two ways. We either build a polymer and to do that we use what’s called
a condensation or a dehydration reaction. Or we break it down. And so let’s start with
building. And so right here we have two amino acids. And so amino acids remember are going
to be put together to make proteins. And so you can see on this first amino acid we’ve
got that alpha carbon in the middle, we’ve got an amino group on one side, carboxyl group
on the other. Likewise with this amino acid, we’ve got an amino group of this side, we’ve
got the carboxyl group on this side and then we have our R groups on either side. And so
basically what happens in a condensation or dehydration reaction, if you look right in
the middle, is we’re going to remove water. In other words we have this hydroxyl group
here and this hydrogen here and so basically what happens is we give off that water, you
can see why it’s called a dehydration reaction. We’re losing water and basically we’re forming
a bond. We’re forming a bond between those two amino acids. In other words we’re making
a simple little polypeptide. And this occurs over and over and over again when we make
a massive protein. Well, what’s the opposite of that? We call that hydrolysis. And I always
think of hydrolysis means water cutting or water breaking. And so let’s say right here
we have a simple disaccharide. This is lactose. What we can do is we can add water to the
system. And we do that, basically what we’re going to do, is we’re going to break that
disaccharide down into two monosaccharides. And so you have enzymes in your body that
are going to help you break down lactose, but we still are going to require a water
every time we break one of those polymers apart. And so basically let me give you a
quick question. You can try to wrap this one around your head. TRP Cage or trip cage is
going to be one of the smallest amino or excuse me, smallest proteins that we have in nature.
And it’s found in the saliva of a Gila monster. And so how many molecules of water would be
required to completely hydrolyze this Gila monster protein. Now you need to know that
there are 20 amino acids that are found in this very small protein. And so how much water
are we going to require to break that up. So it’s a good question. If you want to put
your answers down below do so. And so basically why is this important? Well this is a picture
of me when I was little. And my favorite food, I know this is gross, when I was growing up
was the Filet O Fish sandwich from McDonalds. And so basically when I was eating that Filet
O Fish sandwich it was made up of a number of different polymers, like the polysaccharides
in the starch in the bun and the proteins that are found in the fish in the fillet of
fish and so basically when I took this in and ate it, in digestion I was breaking that
back down into its monomers. But then I was putting those back together again using dehydration
reaction to make the proteins that are found in my hair or my skin or all of the cells
in my body. And so you literally are what you eat thanks to polymers. But again, they
wouldn’t be formed unless we had the building blocks and those are called monomers. And
I hope this is helpful.