Hi all Dr. Clark here again today I'm
going to demo out the fermentation and
cellular respiration lab and the first
part we're going to deal with is
fermentation if you remember when we
talked about fermentation and lecture
fermentation is the process of
glycolysis without oxygen present and if
you do not have oxygen present you'll if
you're a plant or you're a fungi or even
bacteria you will eventually produce
ethanol if you're an animal and you
don't supply oxygen at the end of the
glycolysis process you'll produce lactic
acid okay well today we're going to do
just the first part of that we're going
to break down glucose through glycolysis
using fermentation but we're not gonna
have it go all the way out to produce
alcohol although you could okay it's the
same kind of way and so the first
procedure I'm going to show you here is
again fermentation so what I have here
already weighed out for me because I
just wanted you didn't have to watch me
weigh things out this is 0.5 grams of
yeast yeast is a fungi that can do
fermentation of glucose and will produce
carbon dioxide and eventually would
produce ethanol alcohol okay and so
we're gonna add yeast to 10% glucose and
so 10% glucose and East and that will
allow us to start the fermentation
process I'm going to stick it in to a
fermentation too but we can do it you
can do this at home you can do this any
way you want you just add sugar to water
add a little yeast to it
and you could put a balloon over and
look at the diameter of the balloon for
how much gas is produced in different
environments but today we're going to
just use fermentation vials and when I
look at how much gas is produced in a
normal room environment 22 degrees
Celsius 20 degrees Celsius
eh incubator at 37 degrees Celsius and
then a refrigerator at 4 degrees Celsius
ok so I'm going to go ahead and just mix
these in ok I'm just going to mix them
in stir them up and then I'll come back
and I'll show you how I pour man and do
that kind of process ok so you don't
have to watch me mix things ok so I'm
back
got them all stirred up ready to go so
now I'm just going to pour them into
fermentation vials these are kind of
nice for well the purpose of
demonstrating fermentation they're
fairly expensive pieces of equipment so
I don't suggest if you're going to be
doing you know this for one time that
you would ever purchase one of these
vials but what it allows us to do is
fill this chamber with fluid in this
case with yeast
so that fungi mixed with glucose and
water that's all that's in here and then
look at the production of gas that fills
this chamber over a period of time ok so
I'm just going to take this one I'm
going to leave it on the counter top
it's about 20 degrees Celsius in here ok
and then I'm going to fill these other
two chambers one's going to go into the
incubator at 37 and the other ones going
to go into the refrigerator at 4 degrees
Celsius and
and then we're going to take
measurements of how much gas is produced
at 20 minute intervals 20 minutes 40
minutes and then 60 minutes and I'll
share those results with you I probably
won't show you the measurements after
the first one or maybe the second one
just because it gets kind of redundant
to see me use a ruler make most people
know how to use a ruler so with that I'm
gonna go place these in the incubator
and refrigerator and then I'll come back
and I'll show you how to do the cellular
respiration or at least set up the
cellular respiration portion of this lab
okay and now we're going to do an
experiment on cellular respiration so
we're gonna look at how much carbon
dioxide is produced or in some cases may
be reduced by organisms in a beaker of
water okay so I have six speakers of
water right here they all contain what
we call fish water which basically means
I took it from a fish tank
it has the right microbes in it so it's
not completely sterilized water or
anything like that it has already got
oxygen and carbon dioxide in it and it's
got some aquatic microbes and bacteria
and things like that that are consuming
oxygen and producing carbon dioxide and
things like that so your control is not
an actual perfect control however in
order for the fish to survive and for
the other organisms to survive we kind
of need to have fish water okay so what
I have in this beaker here is the five
organisms that I'm kind of interested in
looking at cellular respiration off and
so in this graduated cylinder I have ten
milliliters of fish water and I'm going
to add one of these individuals one of
these creatures to that just so I can
see what
displacement of the organism is so I can
get the volume of the organism okay the
creature that I'm going to add to it is
leech so I have a leech here in this
beaker and I'm gonna grab him okay there
you can see it there's a leech I'm gonna
drop it in okay and it displaced the
water by three mils and so I'm gonna put
the leech in beaker number one I'm gonna
have to get the leech out of there to
put them in beaker number one so it's
gonna go in beaker number one I'm going
to put a pair film layer over the top so
no oxygen can go in no carbon dioxide
can come out okay
I'm gonna do the exact same thing for a
guppy a goldfish and two alodia plants
and I'll come back and I'll show you the
beaker set up with those organisms okay
but I'm gonna get the volume of all
those organisms first and then I'll come
back I'll share all that data with you
at the very end what the volume is what
their respiration rates and all this
material is at the very end of the
experiment okay so when I come back
these speakers will be full ready to go
to start the the experiment okay okay so
I'm back here are the organisms so
there's a leech and a goldfish a guppy
alodia that's going to be in the light
in the dark and then a control okay so
we're going to wait 40 minutes and I'm
gonna put alodia in the dark I'm going
to put aluminum foil over the top of it
and we're gonna see how much cellular
respiration these different organisms do
over a 45 minute time okay so I'll bring
it back and I'll show you how we're
going to calculate dissolved oxygen
we're going to calculate pH
and then we're going to titrate sodium
hydroxide into phenolphthalein and we're
going to look at another way at which
you can test for production of carbon
dioxide okay so come back in 45 minutes
okay I'm back I'm sorry I didn't show
you the intermediate steps but I got
busy and I just taking measurements so
the measurements for the fermentation
looked like this okay so this was room
temperature I'm just going to show you
the the vials this one's room
temperature this one
what's 37 degrees Celsius and this one
is portable Celsius you can see this one
hasn't changed at all from the original
except for the yeast is settled out this
these are the numbers all right so with
room so you have the data 37 degrees
Celsius at 20 minutes there was eleven
point five millimeters of gas at 40
minutes there's twenty two point four
and at sixty minutes there was twenty
two point four so the maximum really is
about twenty two point four twenty two
point five twenty degrees Celsius two
point four millimeters at twenty minutes
fourteen point one millimeter at forty
minutes twenty two point four
millimeters of sixty minutes so in order
for the yeast to consume basically all
the glucose it takes about an hour to
consume all the glucose at room
temperature if you heat it at 37 degrees
it takes about forty minutes or it's
already done by forty minutes okay and
then at four degrees Celsius there's no
change so you're not going to get
glucose consumption or glycolysis going
on at 4 degrees Celsius okay so that's
the fermentation part we'll come back
and I'll show you the end results for
the cellular respiration part and now
we're going to look at the cellular
respiration that these organisms
produced over a 45 minute period that's
it's been 45 minutes
okay so I'm just going to actually pour
the water out that this organism was in
so then I can actually reach in here and
grab this leech out then toss them back
into a fresh bowl okay so then I can
start testing this water so the first
thing I'm interested in is what is the
pH of the water and I'm just going to
show you one of these and then we're
going to then I'll do the rest and I'll
show you the data of all of them at the
end okay and so the pH of the water that
the leech was in once that gets going at
the same time I'm going to go ahead and
take the dissolved oxygen so I have a
dissolved oxygen probe here also so go
ahead and turn dissolved oxygen probe on
and look at the dissolved oxygen while I
look at the pH so the pH of the control
I'll show you that in a second so you
can kind of base things but normally the
pH of control water for like a fish tank
is in the range of 8 and so the pH of
the leach water okay
is 7.62 and then the P the dissolved
oxygen still going down a little bit but
it's pretty much leveled off at thirty
five thirty five point three thirty five
point three percent so those are those
two methods right now I'm going to go
ahead and show you the titration method
the titration method is going to be
adding phenolphthalein to the speaker
and then titrating sodium hydroxide in
into it until I get a color change and
at that point I'm going to match the
control color to the the rest of the
colors so they're all about the exact
same color and we're going to look at
how many drops of sodium hydroxide it
took to get the exact same colors so
things that are more basic will take
less drops the things that are more
acidic will take more drops okay and so
I'll come back because right now if I do
it you won't see the comparison so I'll
come back and do them all except for one
and then you can see how I do the
titration on the way back okay so I'm
back and I've done the titration for
tube one two three four and five so the
the gup-e alodia in the light alodia in
the dark and the only one I have left is
the control and so you can see that
they're all pretty much the same shade
of pink okay which indicates that
it's all I'm going to do is
phenolphthalein is inside this solution
and now I'm just going to titrate drop
by drop
sodium hydroxide until I can get and
match that same color as you see here
there's one drop two it looks like about
two drops okay so now with that okay
we're about at the same and so it took
more milliliters of sodium hydroxide to
turn pink with things like leeches the
goldfish and the guppy well they're
actually all the same and 0.3 with eel
odeon the light the dark and the control
it took less meaning that those are more
basic these are more acidic which is
what you would expect if cellular
respiration is occurring so your
respiration is occurring carbon dioxide
is being put into the water quranic acid
is forming so the pH of that original
water source is going down and making it
more acidic which means that if you're
indicating for a base which
phenolphthalein and sodium hydroxide are
it would take more drops to get it to
become a base on the flip side of that
if your plants are doing photosynthesis
okay or the Calvin cycle they should be
removing carbon dioxide out of the water
or producing oxygen both in this case
we're testing both okay and that should
make it the instead of being acidic it
should become more basic
here's the results of the research and
I'll you know I'll go through each piece
and hopefully you can see on the camera
I'm gonna try to lit as still as
possible so you can write the numbers
down and whatnot so you can calculate
the relative respiration rate the
respiration rate for millimeters and
then answer the question so first off
the leach its volume was three mils so
displaced three mils of water so I had a
volume of three mils okay it's dissolved
oxygen after 45 minutes was 36.6% the pH
of the water was seven point eight five
and the milliliters of sodium hydroxide
that was needed to change to the same
tent same color was zero point three
mils okay the goldfish for mills was the
volume 31.5%
oxygen seven point nine three pH zero
point three mils of sodium hydroxide so
you can see even though the pH is
different okay the titration is not or
at least our color difference
capabilities is not different enough to
do to differentiate between these three
organisms but that doesn't mean these
three organisms have the same
respiration rate because you will have
to base that off of the volume of the
organism okay so the guppy it's volume
was one point five mils 30.2% oxygen and
dissolved oxygen okay eight point one
one it was the pH zero point three mils
for sodium hydroxide alodia in the light
five mils was the volume 44.8% dissolved
oxygen eight point four one pH zero
point two melts alodia in the dark four
point five mils 41.9% dissolved oxygen
eight point five four
pH 0.2 mils per million okay and the
control there was no volume okay cuz
it's just water
38.8% dissolved oxygen eight point two
one pH and 0.2 ml of sodium hydroxide so
with that you should be able to
calculate the relative respiration rate
and the respiration rate but per
millimeter and get an idea of well what
organisms were respiring and what
organisms were producing oxygen and
removing carbon dioxide or what was the
relative respiration rate okay so you
should be able to finish the lab with
that information and next time I'll
bring you another lab on genetics
