Hi. It's Mr. Andersen and welcome to biology essentials video 49. This podcast
is on cooperative interactions in living systems. And before we get to living systems let's
talk about war and peace for just a second. Now game theory is a way to predict the strategy
that people are going to have or living things are going to have before they actually do
it. And so peace and war is a good one to talk about. And so let's say the year is 2012.
And the country of Finland decides to invade Switzerland. Now this is probably not going
to happen. They both have these neutrality agreements that they've signed. But let's
say that Finland decides in 2012 we're going to go to war with Switzerland. Okay. So if
we look at the payout over here. So let's put Finland on this side and we'll put Switzerland
over here, Finland is going to gain, we'll say 3 units. And Switzerland is going to gain
0 units from that. So if Finland invades and steals all of the Swiss army knives in Switzerland,
they're going to gain from that. Switzerland gets nothing from it. So that's kind of how
the payout is going to be laid out. And so you might think that's cool for Finland. They're
able to grab things. And make off. But the problem is that now 2013 comes. So 2013, Switzerland
has lost all their swiss army knives and now Finland decides, well, let's go at it again.
So they decided that worked really well so they're going to go to war and Switzerland
this time, they're going to steal all of the swiss watches from Switzerland. And now Switzerland
is kind of irritated. They've signed this neutrality act. But now they're irritated.
So the next year, Finland is going to come at them again. So they go to war. But this
time Switzerland is going to figure from this that they're going to go to war as well. So
now we have mutually for the next three years they're in this giant war. So let's imagine
that happens until 2016. So now let's see how this all played out. Well Finland initially
got 6 points but then they eventually ended up getting just 3 more. So they have a total
for 9. Switzerland ended up with 3. And so let's say that's one possible future. It's
probably not a very probable future. But now let's say that Finland decides, you know what,
we've got, let's start with trading with Switzerland. So we'll get their swiss army knives and we'll
export the video game Angry Birds to them, which was created in Finland. And they decided
to go at in peace. And so let's say 2 and 2. And peace continues through time. And then
if we look at the game theory numbers that we get here, after 5 years it would be 10
and 10. And so not only did Switzerland do way better, Finland did way better. In other
words, you're better off if you're at peace. You're better off with cooperation. And in
fact that's this strategy that you should adopt. You shouldn't go to war, but if somebody
does provoke you, then you have to come back at them. And we find that countries that are
continually at war are actually not the richest countries on our planet. So in this podcast
we're going to talk about life. And so how life cooperates to utilize matter and utilize
energy. And so I'm going to talk about this cooperation three fold. First of all we're
going to talk about how single cells cooperate. All the cells that live in the rumen of a
cow for example. We're then going to talk about how cell parts cooperate. How the plasma
membrane works with the cytoplasm and other organelles. And then finally we're going to
finish with larger level. How organs cooperate. An example we'll talk about is digestive system.
So again, cooperation helps everybody who's involved. And so if we think about the rumen
of a cow, a cow is going to have many multiple parts inside their stomach. They're going
to eat the food. It's going to go down into the stomach. It's going to actually go back
into their mouth where they chew their cud. And then it moves back into the stomach. But
I'm not concerned about the cow right now. I'm concerned about the things that live in
the gut of the cow. Or in the rumen of the cow. And so what are some things that live
here? Well bacteria and protozoa. Bacteria are going to be these single cell prokaryotes.
Protozoa are going to be these microscopic animals. These make up like 60% of the organisms
living in the gut of a cow. We also have some fungi. Like some yeast. We also have some
archaea. And then we also have viruses that are living there. And so all of these things
inhabit the gut of a cow. And all of them have to cooperate for their mutual benefit.
And so what are the bacteria and the protozoa do? Well the bacteria are going to be able
to break down a lot of the material, the cellulose, that's going to be found in that plant material.
So they can utilize it. What's the function of the protozoa? Well some of them can also
secrete enzymes that break down that material, but they're also going to keep the bacterial
population in check. What about the fungi? Well the fungi are important, even though
they make something like 5% of the living things in the rumen, they can breakdown specific
bonds between the lignin inside the cellulose. And so if it weren't for fungi, they wouldn't
be able to digest this fully. They couldn't get all their nutrients and so they rely on
the fungi. So there's this reaction. What about archaea. Archaea remember are those
ancient life. Well the important ones inside the gut of a cow are the methanogens, those
that breakdown methane gas. Because if we didn't have, if we had a build up of methane
gas that would actually kill the bacteria, the protozoa and the fungi. And so they're
relying on the archaea. What about viruses? You might think what could viruses possibly
do? Well viruses will actually kill bacteria, releasing their nutrients. And so they can
be used by other things inside the gut. And they also keep that bacteria in check. And
so all five of these organisms and all the probably millions of different species inside
the cow gut have to cooperate. They all have to work together. And if it weren't for them
working together, the cow wouldn't be able to eat what it does. And so it wouldn't be
able to exist as well. So these are cells that cooperating. Let's go to the level of
within the cell itself. And so let's say we're talking for example inside here in the liver.
So let's say this is a liver cell. Let's put an R there. So liver cell is important because
it stores glycogen. So that glycogen is going to be glucose that's attached together. We'll
draw that in black inside here in the cytoplasm of a cell. And so occasionally your body needs
that glycogen to be broken down into glucose. And so you'll have a chemical. That chemical
will bond with proteins on the plasma membrane. If the plasma membrane isn't helping then
this stops there. They'll then be a cascade or a signal transduction pathway which will
move throughout the cytoplasm. So we require the cytoplasm. It sometimes can trigger response
inside the nucleus which releases proteins or excuse me, messenger RNA, which creates
proteins. And those proteins can break down that glycogen into glucose which we can eventually
leave the cell. And so now we have cooperation between many parts of the cell. If it's not
for the plasma membrane, the proteins here, the gene regulation in the DNA, the using
of the ribosomes. They cytoplasm. If they're not all working together we have cell that's
not going to function. And so this is functioning or excuse me, cooperation between organelles.
And then finally we could talk about a whole system. So not only cells working together
but organ working together. Example I've chosen to talk about is the digestive system. So
digestive system. What's it doing? It's taking in food. It's breaking it down so we can use
the parts. But it has to cooperate as well. And so there are four things that we have
to get nutrients from. And those are four major macromolecules. Those are the carbohydrates,
but we'll talk about the other ones in just a second. So where's the digestive system
start? It actually starts with the eye. And that's a creepy looking eye. But the eye is
going to see what I'm about to eat. And it's going to start, I'm going to start to salivate.
And so let's say those carbohydrates are a giant piece of pizza. So it's mostly carbohydrates
inside there. I see that. And I'm going to start creating enzymes in my mouth. Those
are called amylase which is going to breakdown the sugar. It's also going to move into my
stomach where we're not going to work on that too much. But it's going to move into my small
intestine where I'm going to make pancreatic amylase. And that's going to break that down,
the carbohydrate into glucose that I need inside the cells. And so now we've got my
salivary glands. We've got the enzymes in small intestine and the functioning of the
pancreas that's causing that to occur. If we go to the next thing, let's say fats for
example. How does fats work? Well fat's different. We're not going to digest that much in our
mouth. In the esophagus clearly not. Or even in the stomach. But what we do is we start
producing in the lipase, we start producing bile, excuse me, in the gall bladder. The
bile is going to emulsify the fat, so make them smaller. And then we're going to produce
lipases inside the small intestine to breakdown those lipids. Or if we move to another one,
let's say we're breaking nucleic acid. Well we're not going to do much here. We're not
going to do much here. But we're going to breakdown a lot of those nucleic acids in
the small intestine using nucleases that are produced in the pancreas. Finally if we finish
up at proteins, which is maybe the most confusing. Proteins, can't break those down in our mouth
much. But we do produce this hydrochloric acid. We produce pepsin which inside the stomach
is going to breakdown those proteins. We're then going to have trypsin and chymotrypsin
working in the small intestine. So we have all of these organs working together using
feedback loops just to breakdown the food that we eat. And so again, competition is
important. Competition sometimes is good. But if you can cooperate, then you have the
mutual benefit of all those constituent parts involved. And I hope that's helpful.