The Effect of Amylase Concentration and pH Levels on Time of Starch Disappearance

1
The Effect of Amylase Concentration and pH Levels
on Time of Starch Disappearance

• With an Additional
• focus on
• Carboxypeptidase
• By Pauline Hickey, Amanda Clark,
• Peter Crane, Anya Novikova

Carboxypeptidase (1)
Amylase
2
Results Section
3
Our Results Table Our Results Table
Percent Concentration of Amylase Time of Starch Disappearance (in seconds)
0.5 10
0.25 20
0.125 50
0.075 60
Class Average Results Table Class Average Results Table
Percent Concentration of Amylase Time of Starch Disappearance (in seconds)
0.5 16.6
0.25 53.6
0.125 81.6
0.075 223.6

• In both scatter plots, the time required to
  digest starch decreased as the concentration of
  amylase increased.
• Both data bases (our/class) show that there was
  an inverse relationship between the two
  variables.

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Our Results Table Our Results Table
The pH Time of Starch Disappearance (in minutes)
2 9
4 5
6.8 0.5
8 2
10 9
Class Average Results Table Class Average Results Table
The pH Time of Starch Disappearance (in minutes)
2 9
4 5
6.8 0.47 (28 seconds)
8 1.83 (1 minute 50 seconds)
10 8

• Both graphs show that more time was needed to
  digest starch at the highest and lowest pHs.
• The graphs form a V shape that visualize how the
  rate digestion was more rapid towards the middle
  pH of 6.8 and then slowed down again.

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Discussion Section
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Hypothesis 1

• As the concentration of the enzyme Amylase
  increases, the rate of starch disappearance
  increases.
• A.K.A. The rate of starch disappearance is
  directly proportional to the concentration of
  Amylase acting on it.

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Supported?

• Hypothesis WAS SUPPORTED, as seen in graph 1 the
  time of starch disappearance increases relatively
  steadily as the dilution/concentration of amylase
  decreased from .50 to .075
• A.K.A The idea that amylase helps to digest
  starch is supported. Also, when there is more
  (higher concentration) of amylase, starch will be
  broken down more quickly.

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Supporting Background Info

• Supporting background info It amylase
  catalyzes the breakdown of starch. When amylase
  reacts with starch, it cuts off the disaccharide
  maltose (two glucose molecules linked together).
  As the reaction progresses, less starch will be
  present and more sugar (maltose) will be
  present. (2)
• This helps explain why starch breakdown begins in
  the mouth amylase is found in human saliva, so
  as soon as a starchy food like a potato enters
  the oral cavity and interacts with saliva,
  amylase begins to break it down into sugar.
• Amylase is also secreted by the pancreas to
  continue starch digestion in the stomach. (3)

(4)
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Hypothesis 2

• Amylase will be most active at a small, middle
  range of pH (6-8), and will not be active at too
  high or too low a pH.
• A.K.A Starch will disappear most quickly at a
  middle pH range (6-8) and will take much longer
  to disappear at too high or too low a pH.

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Supported?

• Hypothesis WAS SUPPORTED. As seen in graph 2,
  starch disappeared most quickly (only 30 seconds)
  at a middle-range pH of 6.8.
• The starch disappeared most slowly (around 9
  minutes or more) at the extreme lows (2-strongly
  acidic) and extreme highs (10.0-strongly basic)
  pH levels.

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Background Info

• The effective range of pH was hypothesized to be
  within 6 and 8 because the body consists largely
  of water with a pH of 7, and the different bodily
  fluids largely range between 6 and 7.4. (5)

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Sources of Error

• Graduated cylinders, like most forms of
  measurement, have some degree of error, so what
  looked like 5mL measured out may have varied
  slightly and may have caused the time of
  disappearance to go from 10 to 20 to 50 instead
  of 10 to 20 to 40- which would directly
  correspond to the decreasing concentration of
  amylase from .5 to .25 to .125.
• When the dilution was .075, the blue color
  continued to be slightly apparent even after 60
  seconds but the lack of spaces in the tray did
  not allow for the experiment to continue.
• When measuring the amylase in cleaned-out
  graduated cylinders, some water droplets may have
  been leftover and could have slightly diluted the
  amylase more than it was supposed to be diluted,
  which could have lengthened the time of starch
  disappearance, possibly accounting for the jump
  from 16.6 to 53.6 seconds instead of the
  predicted proportional increase of approximately
  16 to around 32 or 33 seconds.

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What would happen at
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80 C?

• Amylase becomes denatureda major change from
  the native state to another state without
  changing the primary structure. (6)
• The speed of the atoms and the strength of their
  collisions increase, which can damage the
  molecular structure- sometimes irreversibly. (6)

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37C.?

• This is the average body temperature and
  therefore the most optimal environment for
  amylase to react with starch.

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22 C.?

• This is about room temperature, which relatively
  cold in terms of amylase. This colder
  temperature, however has not been observed to
  greatly affect the reaction of amylase with
  starch. (6,7)
• Some theories suggest that amylase evolved to be
  able to survive in colder temperatures. It is
  believed that those enzymes which could not stand
  the cold died off, allowing for the more
  temperature-resistant molecules to survive. This
  did not occur with extremely hot temperatures
  because such temperatures are rarely found in any
  climate on earth.(6)

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4C.?

• Even at this somewhat extreme cold, amylase
  continues to react effectively with starch.(6)
• It is believed that amylase evolved to be able to
  function at such low temperatures due to
  naturally-occurring cold climates. (6)

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Digestive Application Carboxypeptidase
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Carboxypeptidase Source, Location of Enzyme
Activity and Substrates

• The source of this digestive enzyme is the
  pancreas 4
• The location of the enzymes activity small
  intestine 4
• Substrates for carboxypeptidase are protein
  fragments 5

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What is Produced From This Hydrolysis Reaction?

• In order to break down a protein (polymer) into
  amino acids (monomers), cells use a hydrolysis
  reaction ? a protein reacts with a water molecule
  to produce an amino acid and a protein 7
• Carboxypeptidase is secreted by the pancreas, and
  speeds up the hydrolysis reaction between the
  protein and the water molecule 8
• The main products of this hydrolysis reaction are
  amino acids which are then small enough to be
  absorbed by the villi in the small intestine7

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What Factors Effect Enzyme Activity?

• As the pH level changes in the small intestine
  and gradually becomes basic, more enzymes are
  activated further that chemically break down
  various nutrients into smaller molecules to allow
  absorption 10
• The ideal pH of the duodenum is 6 to 6.5 11
• The ideal pH of the jejunum and illium is 7.8

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pH Levels in the Digestive System
Digestive enzymes that are located in the
duodenum are most active at a pH of 6 8
Digestive enzymes that are located in the jejunum
and illium are most active at a pH of 7.8 8
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pHs Effect on Carboxypeptidases Activity
100
7.8
24
Temperatures Effect on Carboxypeptidases
Activity

• The temperature of the small intestine is
  approximately 37 degrees Celcius7
• Small fluctuations in temperature change will not
  effect carboxypeptidases activity9
• However, a big increase or decrease in
  temperature will decrease the amount of activity
  by carboxypeptidase11

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Effect of Temperature on Carboxypeptidases
Activity
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References

• http//www.chemistry.wustl.edu/edudev/LabTutorial
  s/Carboxypeptidase/images/cpep.jpg
• Laboratory 5 Enzymes, http//www.und.nodak.edu
  , October 19 2010, http//www.und.nodak.edu/dept/j
  carmich/101lab/lab6/lab6.html
• Amylase, wikipedia.ord, October 19 2010,
  http//en.wikipedia.org/wiki/Amylase
• http//www.istockphoto.com/file_thumbview_approve/
  4643127/2/istockphoto_4643127-starchy-food.jpg
• What is the Normal pH of Blood, Urine and
  Saliva?, www.enotes.com, October 19 2010,
  http//www.enotes.com/science-fact-finder/human-bo
  dy/what-normal-ph-blood-urine-saliva
• Amylase Enzyme The Effects Of Temperature,
  www.allsands.com, October 18 2010,http//www.allsa
  nds.com/science/amylaseenzymeh_wpp_gn.htm
• The Effect That Temperature Has on Enzyme
  Activity, www.docshare.com, October 17
  2010,http//www.docshare.com/doc/163073/The-effect
  -that-temperature-has-on-enzyme-act
• Starr, Cecie and Ralph Taggart. Biology The
  Unity and Diversity of Life. Pacific Grove, CA
  Brooks/Cole, 2001.
• Casiday, Rachel and Regina Frey.
  Enzyme-Substrate Binding Carboxypeptidase,
  http//www.chemistry.wustl.edu October 18 2010,
  http//www.chemistry.wustl.edu/edudev/LabTutorial
  s/Carboxypeptidase/carboxypeptidase.html
• Winsemius, David. What are the pH Levels in the
  Stomach During a Titration of Saliva and Food?
  http//madsci.org October 18, 2010,
  "http//madsci.org/posts/archives/may98/892927858.
  Ch.r.html" http//madsci.org/posts/archives/may98/
  892927858.Ch.r.html
• Boudinot, Sally. Anatomy of the Gastrointestinal
  Tract and Drug Absorption. www.chemcases.com,
  October 19 2010, http//www.chemcases.com/pheno/ph
  eno14.htm
• Temperature of a Healthy Human Body,
  www.hypertextbook.com, October 19 2010,
  http//hypertextbook.com/facts/LenaWong.shtml