Enzyme lab report sample - Weebly
Enzyme
Catalysis
Introduction
Enzymes
are
proteins
produced
by
living
cells
that
act
as
catalysts,
which
affect
the
rate
of
a
biochemical
reaction.
They
allow
these
complex
biochemical
reactions
to
occur
at
a
relatively
low
temperature
and
with
less
energy
usage.
In
enzyme--catalyzed
reactions,
a
substrate,
the
substance
to
be
acted
upon,
binds
to
the
active
site
on
an
enzyme
to
form
the
desired
product.
Each
active
site
on
the
enzyme
is
unique
to
the
substrate
it
will
bind
with
causing
each
to
have
an
individual
three--dimensional
structure.
This
reaction
is
reversible
and
is
shown
as
following:
E
+
S--------ES--------
E
+
P
Enzymes
are
recyclable
and
unchanged
during
the
reaction.
The
active
site
is
the
only
part
of
the
enzyme
that
reacts
with
the
substrate.
However,
its
unique
protein
structure
under
certain
circumstances
can
easily
be
denatured.
Some
of
the
factors
that
affect
enzyme
reactions
are
salt
concentration,
pH,
temperature,
substrate
and
product
concentration,
and
activators
and
inhibitors.
Enzymes
require
a
very
specific
environment
to
be
affective.
Salt
concentration
must
be
in
an
intermediate
concentration.
If
the
salt
concentration
is
too
low,
the
enzyme
side
chains
will
attract
each
other
and
form
an
inactive
precipitate.
Likewise,
if
the
salt
concentration
is
too
high,
the
enzyme
reaction
is
blocked
by
the
salt
ions.
The
optimum
pH
for
an
enzyme--catalyzed
reaction
is
neutral
(7
on
the
pH
scale).
If
the
pH
rises
and
becomes
basic,
the
enzyme
begins
losing
its
H+
ions,
and
if
it
becomes
too
acidic,
the
enzyme
gains
H+
ions.
Both
of
these
conditions
denature
the
enzyme
and
cause
its
active
site
to
change
shape.
Enzymes
also
have
a
temperature
optimum,
which
is
obtained
when
the
enzyme
is
working
at
its
fastest,
and
if
raised
any
further,
the
enzyme
would
denature.
For
substrate
and
product
concentrations,
enzymes
follow
the
law
of
mass
action,
which
says
that
the
direction
of
a
reaction
is
directly
dependent
on
the
concentration.
Activators
make
active
sites
better
fit
a
substrate
causing
the
reaction
rate
to
increase.
Inhibitors
bind
with
the
enzymes'
active
site
and
block
the
substrate
from
bonding
causing
the
reaction
to
subside.
The
enzyme
in
this
lab
is
catalase,
which
produced
by
living
organisms
to
prevent
the
accumulation
of
toxic
hydrogen
peroxide.
Hydrogen
peroxide
decomposes
to
form
water
and
oxygen
as
in
the
following
equation:
2H2O2
?
2H2O
+
O2
This
reaction
occurs
spontaneously
without
catalase,
but
the
enzyme
speeds
the
reaction
considerably.
This
lab's
purpose
is
to
prove
that
catalase
does
speed
the
decomposition
of
hydrogen
peroxide
and
to
determine
the
rate
of
this
reaction.
Hypothesis
The
enzyme
catalase,
under
optimum
conditions,
effectively
speeds
the
decomposition
of
hydrogen
peroxide.
Materials
Exercise
2A:
Test
of
Catalase
Activity
In
Part
1,
the
materials
used
were
10mL
of
1.5%
H2O2,
50--mL
glass
beaker,
1
mL
catalase,
and
2
10-- mL
pipettes
and
pipette
pumps.
In
Part
2,
the
materials
used
were
5
mL
of
catalase,
a
boiling
water
bath,
1
test
tube,
a
test
tube
rack,
10
mL
of
1.5%
H2O2,
50--mL
beaker,
and
2
10--mL
pipettes
and
pipette
pumps.
In
Part
3,
the
materials
used
were
10
mL
of
1.5%
H2O2,
50--mL
beaker,
liver,
and
a
syringe.
Exercise
2B:
The
Baseline
Assay
This
part
of
the
lab
required
10
mL
of
1.5%
H2O2,
1
mL
distilled
H2O,
10
mL
of
H2SO4,
2
50--mL
beakers,
a
sheet
of
white
paper,
5
mL
KMnO4,
2
5--mL
syringes,
and
2
10--mL
pipettes
and
pumps.
Exercise
2C:
The
Uncatalyzed
Rate
of
H2O2
Decomposition
The
materials
used
for
this
section
were
15
mL
of
1.5%
H2O2,
1
mL
distilled
H2O,
10
mL
H2SO4,
2
50-- mL
beakers,
a
sheet
of
white
paper,
5
mL
KMnO4,
2
5--mL
syringes,
and
2
10--mL
pipettes
and
pumps.
Exercise
2D:
An
Enzyme--Catalyzed
Rate
of
H2O2
Decomposition
The
materials
required
for
Exercise
2D
were
70
mL
of
1.5%
H2O2,
70
mL
of
H2SO4,
6
mL
of
catalase
solution,
13
plastic,
labeled
cups,
3
100--mL
beakers,
1
50--mL
beaker,
1
10--mL
syringe,
1
5--mL
syringe,
1
60--mL
syringe,
a
sheet
of
white
paper,
a
timer,
and
30
mL
of
KMnO4.
Method
Exercise
2A:
Test
of
Catalase
Activity
In
Part
1,
10
mL
of
1.5%
H2O2
were
transferred
into
a
50--mL
beaker.
Then,
1
mL
of
fresh
catalase
solution
was
added
and
the
reaction
was
observed
and
recorded.
In
Part
2,
5
mL
of
catalase
was
placed
in
a
test
tube
and
put
in
a
boiling
water
bath
for
five
minutes.
10
mL
of
1.5%
H2O2
were
transferred
to
a
50--mL
beaker
and
1
mL
of
the
boiled
catalase
was
added.
The
reaction
was
observed
and
recorded.
In
Part
3,
10mL
of
1.5%
H2O2
were
transferred
to
a
50
mL
beaker.
1
cm3
of
liver
was
added
to
the
beaker
and
the
reaction
was
observed
and
recorded.
Exercise
2B:
The
Baseline
Assay
10
mL
of
1.5%
H2O2
were
transferred
to
a
50--mL
beaker.
1
mL
of
H2O
was
added
instead
of
catalase,
and
then,
10
mL
of
H2SO4
were
added.
After
mixing
well,
a
5
mL
sample
was
removed
and
placed
over
a
white
sheet
of
paper.
A
5--mL
syringe
was
used
to
add
KMnO4,
1
drop
at
a
time
until
a
persistent
brown
or
pink
color
was
obtained.
The
solution
was
swirled
after
every
drop,
and
the
results
were
observed
and
recorded.
The
baseline
assay
was
calculated.
Exercise
2C:
The
Uncatalyzed
Rate
of
H2O2
Decomposition
A
small
quantity
of
H2O2
was
placed
in
a
beaker
and
stored
uncovered
for
approximately
24
hours.
To
determine
the
amount
of
H2O2
remaining,
10
mL
of
1.5%
H2O2
were
transferred
to
a
50--mL
beaker.
1
mL
of
H2O
was
added
instead
of
catalase,
and
then,
10
mL
of
H2SO4
were
added.
After
mixing
well,
a
5
mL
sample
was
removed
and
placed
over
a
white
sheet
of
paper.
A
5--mL
syringe
was
used
to
add
KMnO4,
1
drop
at
a
time
until
a
persistent
brown
or
pink
color
was
obtained.
The
solution
was
swirled
after
every
drop,
and
the
results
were
observed
and
recorded.
The
percent
of
the
spontaneously
decomposed
H2O2
was
calculated.
Exercise
2D:
An
Enzyme--Catalyzed
Rate
of
H2O2
Decomposition
The
baseline
assay
was
reestablished
following
the
directions
of
Exercise
2B.
Before
starting
the
actual
experiment
a
lot
of
preparation
was
required.
Six
labeled
cups
were
set
out
according
to
their
times
and
10
mL
of
H2O2
were
added
to
each
cup.
6
mL
of
catalase
were
placed
in
a
10--mL
syringe,
and
60
mL
of
H2SO4
were
placed
in
a
60--mL
syringe.
To
start
the
actual
lab,
1
mL
of
catalase
was
added
to
each
of
the
cups,
while
simultaneously,
the
timer
was
started.
Each
of
the
cups
were
swirled.
At
10
seconds,
10
mL
of
H2SO4
were
added
to
stop
the
reaction.
The
same
steps
were
repeated
for
the
30,
60,
120,
180,
and
360
second
cups,
respectively.
Afterwards,
a
five
5
mL
sample
of
each
of
the
larger
cups
were
moved
to
the
corresponding
labeled
smaller
cups.
Each
sample
was
assayed
separately
by
placing
each
over
a
white
sheet
of
paper.
A
5-- mL
syringe
was
used
to
add
KMnO4,
1
drop
at
a
time
until
a
persistent
brown
or
pink
color
was
obtained.
The
solution
was
swirled
after
every
drop,
and
the
results
were
observed
and
recorded.
Results
Activity
Observations
Enzyme
activity
The
solution
only
bubbled
slightly
and
slowly.
Effect
of
Extreme
temperature
The
catalase
had
no
reaction
with
the
H2O2;
there
were
no
bubbles
Presence
of
catalase
The
solution
foamed
up
immediately
Table
1
Enzyme
Activity
Table
2
Establishing
a
Baseline
Volume
Initial
reading
5.0
mL
Final
reading
0.8
mL
Baseline
(
final
volume
?
initial
volume)
4.2
mL
Table
3
Rate
of
Hydrogen
Peroxide
Spontaneous
Decomposition
Volume
Initial
KMnO4
5.0
mL
Final
KMnO4
1.2
mL
Amount
of
KMnO4
used
after
24
hours
3.8
mL
Amount
of
H2O2
spontaneously
decomposed
(
ml
baseline
?
ml
after
24
hours)
0.4
mL
Percent
of
H2O2
spontaneously
decomposed
(
ml
baseline
?
ml
after
24
hours/
baseline)
9.52%
Table
4
Rate
of
Hydrogen
Peroxide
Decomposition
by
Catalase
Time
(
Seconds)
Baseline
KMnO4
10
4.0
mL
30
4.0
mL
60
4.0
mL
120
4.0
mL
180
4.0
mL
360
4.0
mL
Initial
volume
5.0
mL
KMnO4
5.0
mL
5.0
mL
5.0
mL
5.0
mL
5.0
mL
Final
volume
KMnO4
2.2
mL
1.4
mL
2.0
mL
1.7
mL
2.4
mL
2.3
mL
Amount
KMnO4
used
(baseline
?
final)
2.8
mL
3.6
mL
3.0
mL
3.3
mL
2.6
mL
2.7
mL
Amount
H2O2
used
(KMnO4
?
initial)
1.2
mL
0.4
mL
1.0
mL
0.7
mL
1.4
mL
1.3
mL
Amount
of
Hydrogen
Peroxide
Decomposed
by
Catalase
Exercise
2A:
Test
of
Catalase
Activity
1.
Observing
the
reaction
of
catalase
on
hydrogen
peroxide:
a.
What
is
the
enzyme
in
this
reaction?
catalase
b.
What
is
the
substrate
in
this
reaction?
Hydrogen
peroxide
c.
What
is
the
product
in
this
reaction?
Oxygen
&
water
d.
How
could
you
show
that
the
gas
evolved
is
O2?
The
gas
could
be
shown
to
be
O2
if
the
gas
were
collected
in
a
tube,
and
a
glowing
splint
was
held
in
the
tube.
If
the
splint
glowed,
it
would
prove
the
gas
was
oxygen.
2.
Demonstrating
the
effect
of
boiling
on
enzyme
action:
a.
How
does
the
reaction
compare
to
the
one
using
the
unboiled
catalase?
Explain
the
reason
for
this
difference.
While
the
unboiled
catalase
caused
bubbles
to
form
in
the
solution,
the
boiled
catalase
did
not
react
at
all
because
boiling
an
enzyme
causes
the
protein
to
unfold
and
therefore
denatures
it.
3.
Demonstrating
the
presence
of
catalase
in
living
tissue:
a.
What
do
you
think
would
happen
if
the
potato
or
liver
was
boiled
before
being
added
to
the
H2O2?
The
catalase
in
the
liver
would
have
been
denatured
by
the
boiling
and
would
not
have
reacted
with
the
H2O2.
Analysis
of
Results
................
................
In order to avoid copyright disputes, this page is only a partial summary.
To fulfill the demand for quickly locating and searching documents.
It is intelligent file search solution for home and business.
Related download
- student writing guide
- universal rubric for lab reports college of charleston
- writing lab reports
- perception of different sugars by blowflies hamilton college
- writing a lab report chemistry
- physics laboratory report sample
- guidelines for writing lab reports marietta college
- formal labora tory rep ort prince edward island
- perfect lab report
- enzyme lab report sample weebly
Related searches
- photosynthesis lab report experiment
- photosynthesis lab report hypothesis
- college lab report example
- photosynthesis lab report example
- biology lab report example
- chemistry lab report abstract example
- college biology lab report example
- abstract lab report example
- biology lab report abstract example
- chemistry lab report sample
- college science lab report example
- biology lab report introduction example