The Secret of Life

Uploaded by bozemanbiology on 12.09.2012


Hi. It's Mr. Andersen and in this podcast I am going to talk about the
secret of life. And what that means is I'm going to talk about the big picture of DNA
and genes and proteins and how those are all tied together. And so basically all life have
some similarities from a panda bear to bacteria to a chimp to a mushroom. All of them are
made up of cells they have DNA, so they have a lot of similarities. But what is life really
made up of. So if we were to take a Panda Bear and pull a chunk off of that panda bear
and slice it thin, look at it under microscope we would find that it is made up of cells.
And it's got a nucleus in the middle, it's got mitochondria, but if we were to tease
apart those cells what we would find is that most of the cell is actually made up of proteins.
And so when you look at me what you're really looking at is proteins. But if we were to
pull those proteins apart what would we eventually get to, things called amino acids. So those
amino acids are the building blocks of proteins which are the building blocks of cells which
are the building blocks of all life on our planet. So then, what is DNA? We'll we might
know that it's deoxyribonucleic acid, but it basically is a recipe to make proteins
inside you. And if we had the strands of DNA found inside of you we could make a brand
new you. And so let's start with an analogy. Imagine we have a cook book and we want to
use that cook book to make something like pizza. Well, basically the first thing we
do is we wouldn't want to rip out the page so we would copy down the recipe for pizza.
We, the chef would then put the ingredients together and then eventually make the pizza.
And so think of the order I just put those out. So we got a recipe, we then have a chef
and then we finally have the ingredients and we can use that to make a pizza. So now let's
look at DNA, cause DNA is essentially just a cookbook. It's a cookbook to make proteins
and those proteins again make you. And so what's the first thing we need out of that
cookbook, because all of the recipes stay in the cookbook, well we have to copy that
recipe down. And so in the cells we do that by copying down that DNA in something called
messenger RNA. We then have to cook it. And so who are the cooks and whose going to put
those amino acids together. Well in your body those are called ribosomes and those are found
inside the cell. What are the ingredients of proteins then? Those are going to be the
amino acids. And so what is DNA? It's simply a recipe book for all the proteins inside
your body. But it stays locked within the cookbook. Or in us it would be locked within
the nucleus and it just sends it's messenger, messenger RNA out to make the proteins. And
so this is what's called the Central Dogma of life. And so the DNA sits safe within the
nucleus. It makes copies of itself, little bits of itself called RNA, messenger RNA in
this case. We then use that messenger RNA to make proteins. And that proteins make you.
Now we could even draw a line between the DNA and the RNA in eukaryotic cells because
the DNA will sit in the middle and the RNA is going to be the only thing that moves out
into the cytoplasm. So why is this the secret of life? Well little bits of DNA are called
genes. So this could be gene 1, gene 2 and gene 3. And so basically if we look at all
life on our planet, all life has DNA. Where did we get that DNA? We got it from our parents.
And where did they get it? From their parents and parents and parents and parents and parents
back. And eventually if we kept tracing that DNA we'd find that it's not humans anymore.
Eventually it's something, a common ancestor to humans and if we keep going farther back
eventually we get to this first form of life. And so what is happened, in other words what
is life, well life is simply bits of DNA that make proteins, some of those when played against
their environment do well and they're past on from generation to generation. And some
of those genes don't do well at all and they're lost. And so every living thing on our planet
is simply made by bits of DNA, we'll call those genes that have been selected for or
against over time creating the diversity of life we have today. And I think that's pretty
cool. And I hope that's helpful.