Physiology of Digestion - Copy
-
Upload
mada-angeles -
Category
Documents
-
view
219 -
download
0
Transcript of Physiology of Digestion - Copy
-
8/7/2019 Physiology of Digestion - Copy
1/27
-
8/7/2019 Physiology of Digestion - Copy
2/27
Introduction
The digestive system is a portal for nutrients from the
environment to gain access to the circulatory system. Before
such transfer can occur, foodstuffs first have to be reduced to
very simple molecules by a combination of physical and
mechanical digestion. The resulting sugars, amino acids,
fatty acids and the like are then transported across the
epithelium lining the intestine into blood.
Physical digestion refers to the grinding of large pieces of
food into tiny particles while chemical digestion describes
use of enzymes released into the digestive system to break
down large biopolymers into monomers or simple forms.
-
8/7/2019 Physiology of Digestion - Copy
3/27
A. Physical Digestion of Macromolecules
-
8/7/2019 Physiology of Digestion - Copy
4/27
Methodology
1. Stared and imagined how it tastes like
2. Smelled the aroma and imagined its
flavor
3. Took a bite and observed specific parts
of the mouth that ground the food.
Mouth should be as dry as possible before the experimentObservations from start to swallowing were taken note of
-
8/7/2019 Physiology of Digestion - Copy
5/27
Results and Discussion
- Salivate (brought by sight, smell,
taste)- Incisors, Canine, Pre-molar, Molar
-
8/7/2019 Physiology of Digestion - Copy
6/27
B. Chemical Digestion of Carbohydrates
-
8/7/2019 Physiology of Digestion - Copy
7/27
Methodology
C
1
C
2
C
3
C
4
C1: 3.0 ml distilled H2O
C2: 3.0 ml salivary amylase
C3: 3.0 ml salivary amylase with 10
drops HCl
C4: 3.0 ml salivary amylase
solution & place tube in boilingwater for 5 minutes
Added 5.0 ml of starch solution to each tube
and
incubated at 370C water bath for1 hour.
-
8/7/2019 Physiology of Digestion - Copy
8/27
Methodology
C
1
C
2
C
3
C
4
C
1
C
2
C
3
C
4
Check for the presence ofstarch.
(Lugols Test)
-Lugols iodine solution
-Blue to black: Starch is
present(+)
-Amber coloration (-)
Check for the presence of
maltose.
-(Benedicts test)
-5.0 ml Benedicts reagent
*place in boiling H2O for10 mins
-Green (small amts), Yellow
(moderate amts), Orange to Red
(large amts)
-
8/7/2019 Physiology of Digestion - Copy
9/27
Lugols Iodine (Lugols solution, 1829)
a solution of elemental iodine and potassium
iodide in water
consists of 5 g iodine (I2) and 10 g potassium
iodide (KI) mixed with 85 ml distilled water, to
make a brown solution with a total iodine content
of150 mg/mL.
Uses:
As an indicator test for the presence of starch in
organic compounds, with which it reacts byturning a dark blue/black. iodine interacts with
the coil structure of the polysaccharide.
An antiseptic and disinfectant
-
8/7/2019 Physiology of Digestion - Copy
10/27
Results and Discussion
LUGOLS TEST
C1: ++++
C2: +
C3: ++
C4: +++
*presence of starch in all test tubes; they only varied
with the amount of starch present.
-
8/7/2019 Physiology of Digestion - Copy
11/27
Benedicts Reagent
(Benedicts solution orBenedicts Test)
C1: + (remained blue)
C2: ++++
C3: ++
C4: +++
used as a test for the presence of reducing sugars, presence of
aldehyde, and alpha-hydroxy-ketones (e.g. fructose)
used to determine how much reducing sugar is present. contains blue copper(II) ions (Cu2+) which are reduced to copper(I)
(Cu+). These are precipitated as red copper(I) oxide which is
insoluble in water.
-
8/7/2019 Physiology of Digestion - Copy
12/27
EXPERIMENT OBSERVATION INTERFERENCE
Substance in water + 3ml
Benedicts solution, then boil for
few minutes and allow to cool
Red ppt or green ppt or yellow ppt
obtained
Reducing sugar e.g. Glucose is
present
Substance in water + 3ml
Benedicts solution, then boil for
few minutes and allow to cool
Solution remains clear Non-reducing sugar e.g. Sucrose is
present
-
8/7/2019 Physiology of Digestion - Copy
13/27
C. Chemical Digestion of Protein
-
8/7/2019 Physiology of Digestion - Copy
14/27
Methodology
P
1
P
2
P
3
P
4
P
5
Added 5 ml of pepsin toeach tube except P4
P1:10 drops of distilled
water
P2:10 drops of HCl
P3:10 drops of HCl and
put in ice bath
P4: 5 ml of distilled water
and 10 drops of HCl
P5:10 drops of NaOHIncubate all except P3 in 37oC
water bath for 90 mins
-
8/7/2019 Physiology of Digestion - Copy
15/27
Methodology
Examined egg whites slices in incubation.
Took note:
if any digestion occurred
any color change to the solution
* (+) digested with or without color change
* (-) not digested
-
8/7/2019 Physiology of Digestion - Copy
16/27
Results
Set-up Number Observation
P1 (pepsin and water) + fast (second)
P2 (pepsin and HCl) + fastest
P3 (pepsin and HCl on ice) + fast (third)
P4 (water and HCl) + slowest
P5 (pepsin and NaOH) - no digestion
-
8/7/2019 Physiology of Digestion - Copy
17/27
Discussion
Just like our stomach, test tube 2 is very acidic.
Therefore, its acidity caused the fastest
breakdown of protein in the egg white. HCl
somehow speeded up the digestive function ofpepsin.
-
8/7/2019 Physiology of Digestion - Copy
18/27
Temperature also affected the activity of theenzymes as test tube 3 (the one placed in an ice
bath) digested the egg white slower. Too high and
too low temperatures could disrupt an enzymes
function; a moderate temperature is required for
them to work efficiently.
-
8/7/2019 Physiology of Digestion - Copy
19/27
Test tube 1 followed because it does not contain
HCl that would catalyze pepsin. Test tube 4 ranks
fourth because HCl alone cannot breakdown
covalent bonds. Finally, the basic substance in testtube 5 adversely affected pepsin, completely
stopping its digestive function.
-
8/7/2019 Physiology of Digestion - Copy
20/27
-
8/7/2019 Physiology of Digestion - Copy
21/27
D. Chemical Digestion of Triglycerides
-
8/7/2019 Physiology of Digestion - Copy
22/27
Methodology
F
1
F
2
F
3 3.0 ml of cream in each tube
F1: 5.0 distilled H2O + few grains of bile salt
F2: Pancreatin solution
F3: Pancreatin solution + few grains of bile salt
Shook.
Measured INITIAL PHIncubated tubes in 37o C water
bath for1 hour
Measured pH every 20, 40, and 60 minutes
-
8/7/2019 Physiology of Digestion - Copy
23/27
Results
EXPERIMENTAL
F1 F2 F3
START BASIC BASIC ACIDIC
20 minutes BASIC BASIC ACIDIC
40 minutes BASIC SLIGHTLY ACIDIC ACIDIC
60 minutes BASIC SLIGHTLY ACIDIC ACIDIC
THEORETICAL
F1 F2 F3
START BASIC BAS
IC AC
IDIC
20 minutes BASIC BASIC ACIDIC
40 minutes BASIC SLIGHTLY ACIDIC ACIDIC
60 minutes BASIC SLIGHTLY ACIDIC ACIDIC
-
8/7/2019 Physiology of Digestion - Copy
24/27
Discussion
Pancreatin
:mixture of digesting enzymes produced by the
pancreas, including amylase, lipase, and trypsin.
Bile salts
:negatively charged cholesterol derivatives
:amphipathic - both hydrophobic (lipid soluble) and
hydrophilic
:emulsification agents
-
8/7/2019 Physiology of Digestion - Copy
25/27
Lipids aggregate into large droplets minimizingthe surface area of contact between fat and
water.
Digestive enzymes are hydrophilic, only able to
digest molecules on the surface. Amphiphatic molecules break down fats droplets
to tiny emulsification droplets.
Lipases can come contact with the triglycerides
and hydrolyze them into amphiphatic free fattyacids and monoglycerides.
-
8/7/2019 Physiology of Digestion - Copy
26/27
Conclusion
For food to be utilized by the body, it must
first undergo a series of processes which we
call digestion. After we perform the only
really voluntary actions involved in theprocess of nutritionputting the food into our
mouths, chewing and swallowingthe
balance of the digestive process is the
function of the autonomic or involuntarynervous system.
-
8/7/2019 Physiology of Digestion - Copy
27/27
THE END.
February 15, 2010