This document is a ratification page for a biology practicum report on the influence of pH on enzyme activity. It provides details of the student who conducted the practicum such as their name, student number, group, and class. It documents that the practicum report was checked and accepted by the assistant coordinator and assistant. The practicum was conducted on November 22nd 2011 from 10am to 12:30pm in the biology laboratory at FMIPA UNM. It involved studying the effect of pH on the activity of the enzyme amylase by adding extracts to solutions with varying pH levels and observing the color changes after heating. The student concluded that enzyme activity is most significant at a neutral pH of around 4.5-4

1. RATIFICATION PAGE
Complete report of Basic Biology practicum with title “The Influence of pH
on enzyme activities’’ that arranged by
:
Name
: Jeny Ayu Hardiah Ningrum
Registrasion Number
: 1114040162
Group
: III (Three)
Class
: ICP A
After checked by Assistant and Assistant Coordinator so this report was
accepted.
Makassar, November 26th 2011
Assistant Coordinator
Assistant
(Djumarirmanto, S.Pd)
(Engka Rukmana)
ID. 091404173
CHAPTER I

2. INTRODUCTION
A. Background
This is one of kinds of the subject and chemistry, this subject is not of
new word for me because we have hot it in junior high school, senior high
scool and now in university. this word is enzyme, we have known if were
living thing and we have known also about all substance in the word. Ther are
alements and compounds, and we would try to discussed about compounds.
Enzyme is one of the kinds catalisator and compounds, we have
known about the meaning, the function and advantage of enzyme, that are all
we have got in the pas time before we done this practicum, so that we must to
easy to done this practicum learn about enzyme.
This practicum also discussed about pH, and us we know that if pH is
one of the way to know the activity of enzyme amilaze, so that if we want to
known the activity of enzyme we must to known about pH before practicum,
pH is manner to known the condition of solution are acid od bases, most of
what we known about how enzymes work is gained from studying them in
vitro, usually one isolated test at a time, but a living cell may have the
potencial for many thousands of tests, so it is immediately evident. The major
task of metabolism is provided energy for the maintenance of life, this is
accomplished by degrading chemical compounds of relatively high potential
energy to products of low potential energy.
So that to known about pH and enzyme in this practicum, to known
about function of pH and enzymes in this practicum, and to known about the
advantage of pHand enzynein this practicum, we must to done this practicum
seriously, but if don’t seriously we we will do fault,as insert material excess,
and result that at wants not also as one of original.
B. Purpose
To prove the effect of pH on enzyme activity.

3. C. Benefit
Student at university could know proved the effect of pH of enzyme amilaze.
CHAPTER II
PREVIEW OF LITERATURE

4. Enzymes can be found in both animals and plants, One of the enzymes
contained in plants is amilaze, another name of amilaze is diastase. The enzyme
can hydrolyze
starch to sugar, amilaze
produced by the leaves or seeds are
germinated. Amilaze activity is affected by inorganic salts, pH, temperature, light,
pH optimum of amilaze according to Hopkins, Cole and green (Miler, 1983) is 4,5 to
4,7 (Tim Pengajar, 2011).
One of the distinguishing characteristics of living organisms is the presence
within them of the special catalysts called enzymes. The existence of these catalysts
in living tissues accounts for the rapid execution and control of an exceedingly large
number of biochemical tests. Enzymes posses all the properties we have noted for
catalysts in general. The speed up tests that are otherwise so slow that they would
virtually never occur: the are not consumed in the tests and in small e amounts
perform much work. In addition, they mentioned. Although enxymes are produced
only by living organisms, they may be sprout extracted from tissues, purified,
crystallized, and studied in isolation. Through such studies, the knowledge of
enzymes and their catalytic properties has expanded dramatically in the last two
decades (Simpson, 1965).
Enzymes, In enzymatic tests, the molecules at the beginning of the process,
called substrates, are converted into different molecules, called products. Almost all
chemical tests in a biological cell need enzymes in order to occur at rates sufficient
for life. Since enzymes are selective for their substrates and speed up only a few tests
from among many possibilities, the set of enzymes made in a cell determines which
metabolic pathways occur in that cell.Like all catalysts, enzymes work by lowering
the activation energy (Ea‡) for a test, thus dramatically increasing the rate of the test.
As a result, products are formed faster and tests reach their equilibrium state more
rapidly. Most enzyme test rates are millions of times faster than those of comparable
un-catalyzed tests. As with all catalysts, enzymes are not consumed by the tests they
catalyze, nor do they alter the equilibrium of these tests. However, enzymes do differ
from most other catalysts in that they are highly specific for their substrates. Enzymes

5. are known to catalyze about 4,000 biochemical tests. A few RNA molecules called
ribozymes also catalyze tests, with an important example being some parts of the
ribosome. Synthetic molecules called artificial enzymes also display enzyme-like
catalysis. Enzyme activity can be affected by other molecules. Inhibitors are
molecules that decrease enzyme activity; activators are molecules that increase
activity. Many drugs and poisons are enzyme inhibitors. Activity is also affected by
temperature, chemical environment, and the concentration of substrate. Some
enzymes are used commercially (Anonymous a, 2011).
The amount of practicular enzyme present in a cell can be regulated at several
steps in the production of the enzymes and, of course at the stage of enzyme
degradation. In the metabolic control hierarchy, the most complex mechanism for
regulating enzyme concentration involves the processes of gene activation on
repression. In response to specific chemical signals, the transcription of given DNA
sequence into messenger RNA (mRNA) may be initiated or blocked, depending on
whether the signal in questior, is an “inducer” or “repressor” respectively. Gene-level
control can lead to a) increased or decreased quantities of enzymes, b) changes in the
types of enzymes which occur in the cell, c) changes in the relative abundance of
enzyme variants (or isozymes), each of which catalyzes the same given test but, may
display specific catalytic properties (Peter, 1984).
Enzymes being proteins, cannot wishtand the action of strong acid or base.
however, even over pH range in which inactivation does not occur, enzymes exhibit
optima in their activity. In the case of an enzyme which attacks non-ionic subrates,
the optimum pH constant for some particular configuration of electrical charges on
the reactive surfaces of the enzyme protein, in which condition the action on the
subsrate is most efficient. As in the case of the temperature effect, the very existence
of an optimum in the curve suggest the action of two opposing forces. In the case of
the pH effect, it has been suggested that at least two ionizable groups are involved at
the active site. Having different pK`s, an idea which is in agreement with recent
theories concerning the chemical groups at the active site. Ionized subrates will

6. themselves vary in electrical properties over the pH range, so that enzymes attacking
such substances often show pH optima which differ one subrate to another
(Cantarow, 1962).
According to (Anonymous b (2011), Enzymes work in a similar way (locks
and keys). Enzymes complete very specific jobs and do nothing else. They are very
specific locks and the compounds they work with are the special keys. In the same
way there are door keys, car keys, and bike-lock keys, there are enzymes for neural
cells, intestinal cells, and your saliva. Here's the deal: there are four steps in the
process of an enzyme working.
1. An enzyme and a substrate are in the same area. The substrate is the biological
molecule that the enzyme will attack.
2. The enzyme grabs onto the substrate with a special area called the active site The
active site is a specially shaped area of the enzyme that fits around the substrate.
The active site is the keyhole of the lock.
3. A process called catalysis happens. Catalysis is when the substrate is changed. It
could be broken down or combined with another molecule to make something
new.
4. The enzyme lets go. Big idea. When the enzyme lets go, it returns to normal, ready
to do another test. The substrate is no longer the same. The substrate is now called
the product.
CHAPTER III
PRACTICUM METHOD
A. Time and Place
Day / Date
: Monday/November 22nd 2011

7. Time
: 10.00 A.M until 12.30 P.M
Place
: Biology laboratory 3rd flour at FMIPA UNM
B. Tool and Material
1. Tools
a)
Test tube
b)
Pipette
c)
Rack of Test tube
d)
Bunsen bunner
e)
Baker glass
f)
Tripod
2. Materials
a)
Sprout extract
b)
Amilum solution
c)
Fehling a and fehling b solution
d)
HCL solution
e)
NaOH solution
f)
pH meter
g)
Aquades
C. Work procedure
1. Prepared ten of test tube, give label for all tubes (A 1A2A3, B1B2B3, C1C2C3,
and D) then fill all test tube with amilum solution 1ml.
2. Fill extract 1 ml for test tube A, then checked pH and colour, after that
tube test A1 idled for five minutes, A2 idled for ten minutes, and A3 idled
for fifteen minutes, after that heated for two minutes.
3. Fill extract 1 ml for test tube B, added HCL solution three drops,give
fehilng a and fehling b, then checked pH and colour after that test B1 idled
for five minutes, B2 idled for ten minutes, and B 3 idled for fifteen minutes,
after that heated for two minutes.

8. 4. Fill extract 1 ml for test tube C, added NaOH solution three drops, then
checked pH and colour, give fehling a and fehling b, after that test C 1 idled
for five minutes, C2 idled for ten minutes, and C 3 idled for fifteen minutes,
after that heated for two minutes.
5. Fill fehling A and B 1 ml for test tub D, and seen colour, after that heated
for two minutes.
6. Heated all test tube after idled five minutes concide, and with solution
after idled ten minutes and fifteen minutes.
7. Compared the result of all tubes and made table of its result.
CHAPTER IV
OBSERVATION RESULT
A. Observation Result
Table of the result of practicum:
No
Tube
pH
First colour
Last colour

9. 1
A1
7
Dark to blue
Dark to green
A2
7
Dark to blue
Dark to green+
3
A3
7
Dark to blue
Dark to green++
4
B1
1
Light blue
Light blue
B2
1
Light blue
Dark blue+
6
B3
1
Light blue
Dark blue++
7
8
C1
C2
11
11
Dark to blue
Dark to blue
Green to blue
Green to yellow
2
5
A
B
C
9
C3 11
Dark to blue
10
D
D
Blue to red
The picture of the tubes from our experiment:
1) Tube A
Before heated
2)
3)
After heated
A1
Tube B
Before heated
Tube C
Yellow to red
Light purple
A2
A3
After heated
B1
B2
After heated
B3

10. Before heated
4)
C1
C2
C3
Tube D (Control)
Before heated
After heated
B. Discussion
1) Tube A
Tubes A divided into three tube with contained amilum, they are A1,
A2, A3, added extract and after that we got ph 7,then heated ,tube A1 which
heated during fove minutes until two minutes and was changed colour
from dark blue to dark green. Tube A2 which had heated during ten
minutes and and was changed colour from dark blue to dark green + and
tube A3 which had heated during fifteen minutes and was changed colour
from dark blue to dark green++. This solution perfect because necessarily
pH which at gets is 7 because get natural characters
2) Tube B
Tubes B divided into three tube with contained HCL, they are B 1, B2,
B3 ,added extract and after that we got ph 1, then heated ,tube B 1 which
heated during five minutes until two minutes and was changed colour
from light blue to light blue. Tube B2 which had heated during ten minutes
and and was changed colour from light blue to dark blue + and tube B3
which had heated during fifteen minutes and was changed colour from

11. light blue to dark blue++. This solution imperfect because necessarily pH
which at gets is 8 until 14 because that solution gets acid character
3) Tube C
Tubes C divided into three tube with contained NaOH, they are C 1, C2,
C3 ,added extract and after that we got ph 11, then heated ,tube C 1 which
heated during five minutes until two minutes and was changed colour
from Dark blue to green blue. Tube B 2 which had heated during ten
minutes and and was changed colour from Dark blue to green to yellow
and tube B3 which had heated during fifteen minutes and was changed
colour from dark blue to yellow to red . This solution imperfect because
necessarily pH which at gets is 0 until 6 because that solution gets basic
character
4) Tube D
Tube D we used been control tube, because we just dropped Fehling A
and fehling B into the tube, then heated and was changed colour from
blue to red to purple (control negative)

12. CHAPTER V
CONCLUSION AND SUGGESTION
A. Conclusion
After we done this practicum, we could know the mind of this
experiment, we could know and we could conclude if the experiment of the
influence of pH influenced the activity of enzyme is more big. Enzyme
couldn`t work if small pH, and high pH. Enzyme also couldn’t work if the
hight temperature or the small temperature, with the other word, enzyme
could to study when the pH there on the normal situation and on the normal
temperature, pH of amylase according to Hopkins, Cole, and Green (Miller,
1938) is 4,5-4,7
B. Suggestion
1. Suggestion for laboratory
I hope for next practicum tools and materials that need for practicum must
complete and better in order practicum is success. And Bunsen bunner
better utilizes that easy burning
2. Suggestion for Assistant

13. I hope assistant could give attention for practican about pH normal for
enzyme activity.
3. Suggestion for the all friends
I hope all practicans could understand, and did not take pipette two-time
with different solution
BIBLIOGRAPHY
Anonymous a, 2011. Enzymes.http://en.wikipedia.org/wiki/Enzymes. Accessed at
November 20th 2011.
Anonymous b, 2011. Enzymes www.chem4kids.com/files/bio_enzymes.html.
Accessed at November 20th 2011.
Cantarow, Abraham. 1962. Biochemistry. USA: W.B.Saunders company
Simpson, George Gaylord. 1965. Life An Introduction to biology. New York:
Harcourt
Peter, Hochacka.1974. Biochemical Adaption. London: Princeton university.
Tim Pengajar, 2011. Penuntun praktikum biologi dasar. Makassar: UNM