00:00
So let's take a look at this visually.
00:02
Now relax, you're not going to have
to draw this, I just want you to see it.
00:07
For those of us that are really visual people, it
helps you remember this when you can see it.
00:12
So we're gonna look at deamination
and how we end up with ammonia.
00:17
So look you've got... we broke off that amino acid,
and look at that fellow that's over on
the other side of your screen come in.
00:23
There you go.
00:24
When it connects, we end up with NH3.
00:29
Ammonia contains one
nitrogen, you see that blue ball
and three hydrogen, you see them
right there - boom, boom, boom.
00:38
So that's how we end up with ammonia - deamination.
00:42
You got an amino acid removed hooked up with
another hydrogen and boom! you've got ammonia.
00:48
Now, why is that a problem?
Well, look what's going on in that slide.
00:53
Those little ammonia suckers are attacking
your central nervous system - your brain.
00:59
Too much ammonia is toxic to your brain.
01:02
Let me stop and pause right there.
01:06
Yeah, too much ammonia - toxic to your brain.
01:10
Now why would I stop and stare at you for
just a minute because this is crucially important.
01:16
When someone's liver is not functioning, then I
know wow, I got to take a look at that ammonia level,
was that being affected by it?
People who have cirrhosis, or livers that are really
struggling are going to have high ammonia levels,
I'm gonna watch them for CNS changes.
01:30
People that have too much protein might
end up with high ammonia levels, right?
That's what the BUN tips us off to.
01:37
So keep in mind protein metabolism - essential for life.
01:41
When I break down the protein, I end
up with ammonia as a waste product.
01:47
If I've got more than my body can
handle, it's gonna be toxic to my brain.
01:52
That's why I've got rely on a strong healthy
liver to take that ammonia and turn it into urea.
01:58
Now why do I want urea?
because it's highly soluble in water.
02:03
Okay, write that in your notes:
urea - highly soluble in water
Okay so that's a safe vehicle for the body to
transport that and get that out with all the excess nitrogen
So if I turn the ammonia into urea, that
will help me transport that ammonia product
when I change it into urea and
get rid of that excess nitrogen.
02:26
So remember that we're looking at BUN, that's
how we're gonna get rid of your urea and nitrogen.
02:32
So let's walk through how the liver
does that, how does it break it into urea?
Well we know this is a protective function
of the brain cause we're looking at CH4...
02:43
Yeah, don't worry about the actual
chemical formula, just keep in mind,
the liver protects the brain by transforming ammonia
to something that we can pee out of our bodies.
02:54
Makes sense?
So let's look at it graphically, first start with a nitrogen
and nitrogen combine with other elements to form urea.
03:02
There you go.
03:03
The elements nitrogen combined with are carbon.
03:06
So see in our picture you see the nitrogen
and then you see the little grey ball for the carbon.
03:11
Now the elements of nitrogen combined
with our carbon and four hydrogen,
don't memorize this, okay?
This isn't the part I need you to remember, I just
want you to see the process and how it goes down.
03:25
So look we've got the elements of nitrogen
combining with carbon, hydrogen and one oxygen.
03:32
boom bada bing! there's urea.
03:35
That's how it goes from what we had originally into urea.
03:40
Now it's a chemical waste product
that can be excreted by the kidneys.
03:44
Ammonia can not be excreted by the kidneys but urea can.