Name ___________________________________________________ Hour ______________
Biology Digestive Labs
Due March 26th
Lab
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Data Table
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Fantasy
Food lab
Data Table
Math
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HW
Analyzing Digestion
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Fat Digestion
Lab
Your Points _________
Total Points 30 Possible pts
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Fat Digestion Lab
I. Introduction
Digestion is a process in which fats, protein, and carbohydrates are changed chemically into less
complex molecules. These changes usually are caused by the chemical action of enzymes. Enzymes
are produced by many oranges of the digestive system. Digestion can occur in a test tube with the
proper chemicals supplied. Color changes in certain chemicals can show if digestion has occurred.
Litmus is a chemical that can be used to show if fat digestion has occurred. Litmus in the presence
of fat is purple. Litmus is pink in an acid environment. When fat is digested, it is changed into fatty
acids. Litmus changes to dark pink and then to light pink if the fat is broken down into fatty acids.
This color change can, therefore, show if fat digestion ahs occurred.
In this investigation, you will
a) use litmus to determine if fat (cream) digestion occurs.
b) Determine how lipase and bile affect fat digestion rate.
II. Materials
Test tubes – 3
Cream
Litmus solution
Bile solution
Lipase solution
water
dropper
III. Procedure
A. Label test tubes one to four.
B. To each of the tubes, add 1 inch of water, one drop of cream, and 20 drops of litmus.
C. Mix the contents of each tube.
D. Record the exact color of each tube in the column marked “at start” in Table 1. Use these
colors: purple, dark pink, light pink.
Tube
Tube
Tube
Tube
DROPS
OF
LIPASE
0
20
20
0
1
2
3
4
E.
F.
G.
H.
I.
TABLE 1. FAT DIGESTION RESULTS
DROPS
COLOR
OF BILE AT START
End of Class
0
0
5
5
To tube two, add 20 drops of lipase enzyme.
To tube three, add 20 drops of lipase enzyme and five drops of bile.
To tube four, add 5 drops of bile.
Mix the contents of each test tube by inverting the test tube.
Set the tubes upright and wait ten minutes.
24 HOURS LATER
J. At the end of End of Class, mix again and observe the color within each tube. Hold the test
tubes toward the light to observe the color changes. Because color changes may not be
readily apparent, compare each solution with the other solutions. Record the colors (use only
blue, dark pink, or light pink) in Table 61-1.
K. After 24 hours mix again and observe the color of each tube. Hold the test tubes toward an
artificial light source to observe the color changes. Record the colors in Table 1. (Use only
blue, dark pink, or light pink.)
Analysis:
1.
(a) What was used in this experiment as the source of fat?
_______________________________________________________
(b) Why was lipase used in this experiment?
_______________________________________________________
_______________________________________________________
(c) What was the purpose of using litmus in this experiment?
______________________________________________________________________
________________________________________
2. (a) Which test tube showed the lightest pink color after twenty minutes? __________
(b) Which test tube showed the most fat digestion after twenty minutes? __________
(c) What chemicals were added to this tube?
_____________________________________________________
3. (a) Which test tube showed only dark pink color after twenty minutes?
____________
(b) Which test tube showed only some fat digestion after twenty minutes? _________
(c) What chemicals were added to this tube?
____________________________________________________
4. (a) Which test tube remained blue in color after twenty minutes?
________________
(b) Which test tube showed no fat digestion after twenty minutes? _______________
(c) What chemicals were added to this tube? ________________________________
5. (a) What is the function of enzymes in the human body? (Consult your text and notes)
_____________________________________________
_________________________________________________________________________
_________________________________________
(b) What is the function of bile in the human body?
_________________________________________________________
6. Which test tube contained those chemicals most similar to those found in the intestine during
fat digestion? _____________________________________________________
7. What experimental evidence do you have to show that bile helps speed up fat
digestion?______________________________________________
8. What experimental evidence do you have to show that bile is not needed in fat digestion?
________________________________________________________
Fantasy Food Log (USE table in homework packet at the back)
Directions: Design a make believe (FANTASY) diet using the classroom packets given in class by
listing something to eat for breakfast, lunch and dinner and snacks (optional). Then add up each
column. After totaling your numbers you can determine if you went over or were under your
recommended daily amount of nutrient intake.
Total Calories
Fat gram(s) x 9 Cholesterol
Sodium (mg)
= fat calories
(mg)
Breakfast items
Lunch items
Dinner items
Snacks
Total: add
breakfast lunch
and dinner
Complete the following equations:
1. What is your BMR? __________ (show work here)
Hints: Note kg’s = (weight in lbs) x (0.41)
Basal Metabolic Rate = (Weight in kilograms) x (0.8) x (24 hours)
2. What is your FPE? ___________(show work here)
Food processing energy = 10% of your Basal Metabolic Rate
3. How many calories did you burn during your day of driving? _________
Activity = the energy used to drive, take pictures, etc. = (BMR)(0.35)
4. What is the total number of calories you burned in this day? _________________
(show work here)
Total calories = (Basal metabolic rate) + (Food processing energy) + (Activity)
Questions:
5. How many calories did you consume?
6. What percent of these calories came from fat?
7. How much are you over or under the recommended fat percentage? (30% RDA)
8. How many milligrams of sodium did you consume?
9. How much are you over or under the recommended sodium allowance? (2400 RDA)
10. Did you go over your cholesterol limit? (300 RDA)
11. How much above or below the cholesterol limit were you?
12. Let’s estimate the number of calories you burn in a typical day: (use back of notes packet to
help by determining what activities you did today)
EXTRA CREDIT
If you did not use all the calories you ate, then use the tables of exercise data to write a specific
plan for using the surplus calories. Thus, preventing their storage as fat: Be sure the math is
clearly shown.
Analyzing Digestion in the Stomach
You are scheduled to participate in a track meet at 4:00 p.m. this afternoon. You want to do your best.
You know that a “good” meal will help you to perform well. What kind of meal is best for you? When
should you eat it? In this activity you will analyze the factors that affect digestion in the stomach. You
cannot get the most energy from foods that you have not completely digested. Foods in you stomach have
not been completely digested. The process of digestion is completed in the small intestine. Also, you do
not have much control over the amount of time foods remain in your stomach. The amount of time
depends on the kinds of food that you have eaten. And you do have control over that.
Many factors affect the amount of time in which food remains in your stomach. Examples include the
chemical makeup of the food, the physical state of the food, and your emotional state. The level of
activity that you engage in immediately after you eat also affects the amount of time I which food
remains in your stomach.
In terms of chemical makeup, foods are classified into three categories. Carbohydrates (sugars and
starches) provide immediate energy for the body’s activities. Proteins are used for growth and the repair
of body tissues (in other words making other proteins). Fats are a form of stored energy. Because
stored fat must be broken down in the body’s cells before it is used, stored fats are not a quick form of
energy. Use Table 1 and 2 to answer the following questions.
Table 1:
Food
Carb
Bacon
Fat
X
Bread
X
Butter
X
Chicken
(without skin)
Steak
Food
Lean
hamburger
Fat
Protein
X
X
X
X
X
Orange
X
Potato
(boiled)
X
French fries
X
Potato chips
X
Spaghetti
Table 2: Time various foods stay in the stomach
Bread, spaghetti, rice, orange
Chicken, lean hamburger, steak
Bacon, butter, cream
1.
Carb
Low fat milk
X
Cereal
Cream
Protein
X
2-3 hours
3-4 hours
4-6 hours
Which kind of food remains in the stomach for the longest period of time?
2. Which food remains in the stomach for the least amount of time?
3. A meal of 2 scrambled eggs, 2 slices of toast, 2 slices of bacon and coffee with cream and sugar
can remain in the stomach for up to 6 hours. A meat loaf sandwich, mashed potatoes, and coffee
without cream or sugar remains in the stomach for about 4 hours. Which nutrient appears to
influence the time it takes for the stomach to empty?
4. Steak and hamburger are both protein rich. Steak typically will remain in the stomach longer than
hamburger. Propose a reason for this.
5. Fried chicken usually remains in the stomach longer than baked chicken. Explain why.
6. Why do you become hungry more quickly after a meal of cereal and toast than after a meal of
bacon and eggs?
7. Becoming angry or tense while you are eating often decreases peristalsis of the stomach. What
effect do these emotions have on the time food stays in the stomach?
8. It is generally desirable for an athlete to compete on an empty stomach. During vigorous
exercise, the blood flow to the digestive system decreases. If food is in the stomach, the
decreased flow of blood may cause cramps. Keeping in mind the roles of carbohydrates, fats, and
proteins play and the amount of time they stay in the stomach, choose a menu from the list below
that would be best for an athlete to eat three hours before a competition. Explain the reasoning
behind your choice.
a. Cheeseburger, French fries, low fat milk
b. Steak, potatoes, low fat milk
c. Orange juice, cereal, low fat milk, potatoes
HW Biology
Digestion of Nutrients:
This chart shows the step by step changes for fats, proteins, and carbohydrates as they pass through the
digestive system. Study one nutrient at a time and follow its pathway through the chart. Color each square the
color indicated to help follow each nutrient.
Enzyme for
Where is this
physical or
Carbohydrate
Protein
Fat
digestion at
enzyme
chemical
(red)
(blue)
(green)
this point.
made?
change
Salivary
Double sugar
amylase
Salivary glands
C
(red)
(red)
Pepsin and
Polypeptide
hydrochoric
Stomach
C
(blue)
acid
(blue)
Emulsified fat
Bile
Liver
P
(green)
(green)
Peptide
Trypsin
(blue)
(blue)
Fatty acids and
Lipase
glycerol
Pancreas
C
(green)
(green)
Polysaccharide
Pancreatic
to double sugar
amylase
(red)
(red)
Amino acids
Erepsin
(blue)
(blue)
Various
Single sugar
bacterial
Small Intestine
C
(red)
hydrolases
(red)
1. What is the final form into which each nutrient is changed?
a. Fat –
b. Carbohydrate –
c.
Protein –
2. Describe the changes needed to digest the following nutrients:
a. Fat –
b. Carbohydrate –
c.
Protein –
3. Name all the enzymes used to digest each nutrient and tell where they are used:
a. Fat –
b. Carbohydrate –
c.
Protein –
4. Which organ makes enzymes that digest all three types of nutrients?
Review macromolecules and their monomers, structural formulas, chemical formulas, etc
5. Write the one formula used by Heterotrophs here:
+
+
6. Define these terms and write their letters near each part of the digestion system that they
occur in on the following diagram of the digestive system.
a. Ingestion (I) –
b. Peristalsis (P) –
c.
Absorption (A) –
d. Elimination (E) –
e.
Mechanical Digestion (M) –
7. What increases the surface area of the small intestine to allow for more absorption of
macromolecules?
8. Label the following 10 digestive parts in the diagram and define what each part does.
1. ___________________ ______________________________________
1
2. __________________
______________________________________
2
7
3. _____________________
_______________________________________
4. ___________________
_______________________________________
3
4
5. ___________________
_______________________________________
8
9
5
6. ____________________ ______________________________________
6
7. ______________________ _______________________________________
8. _______________________ _______________________________________
9. _______________________
_______________________________________