lab 39- Digestion Flashcards
Enzymes are _______ that increase the rate of chemical reactions without becoming a part of the product
catalysts
True or False:
When you use iodine to test for starch, a color change to blue-black indicates a positive starch test
true
One enzyme that we used in lab is produced by the salivary glands and secreted into the mouth where is hydrolyzes starch to maltose. Name this enzyme.
salivary amylase
If Benedict’s test in the starch assay produces a ___________ precipitate, then your test will be recorded as positive for maltose.
green to orange
The enzyme ___________ , produced by the pancreas, is responsible for breaking down proteins.
trypsin
The enzyme ___________ hydrolyzes neutral fats to their component monoglycerides and fatty acids
pancreatic lipase
True or false:
Both smooth and skeletal muscles are involved in the physical processes of digestion
true
___________ movements are local contractions that mix foodstuffs with digestive juices and increase the rate of absorption
segmental
What are substrates?
The molecules on which enzymes act on (in this experiment substrates are the food molecules)
Digestive enzymes are also called ________
hydrolases
How to substrates break down into monomers?
hydrolases (digestive enzymes) break down the substrate by adding water to the molecular bonds (one H from one molecule and one OH from another), thus cleaving the bonds between the subunits or monomers
The two enzymes involved in starch digestion are ________ and ________
salivary amylase and pancreatic amylase
Starch breaks down into ________ by ________
maltose by salivary amylase
The experiment must have ________ to provide a standard against which comparisons can be made.
controls
IKI tests the solution for ________
starch
When IKI i sadded to a solution a blue-black color indicates the presence of ________ and is called a ________
starch, positive starch test
If the solution turns orange after IKI is added this is a ________
negative starch test
What indicates a positive sugar test?
When the solution turns orange after Benedict’s solution is added
If the solution turns blue after adding Benedict’s solution this is a ________
negative sugar test (Benedict’s solution is blue)
Trypsin breaks down ________
proteins
Trysin is produced by the ________
pancreas
BAPNA is a ________
color indicator (goes from colorless to bright yellow if protein is broken down into amino acids
If the solution turns yellow when BAPNA is present this indicates a _____________
positive hydrolysis test (amino acids are present)
What color will the solution be if a negative hydrolysis occurs when BAPNA is added?
no color change
Why would a benedict’s solution turn green?
Because it’s in between changing from orange to blue-black, maybe you didn’t wait long enough for the glucose chain to denature
Litmus powder indicators detect __________
pH
Alkaline or neutral solutions turn litmus _____________
blue
Acidic solutions turn litmus ___________
reddish
Since fats are digested to ________ during hydrolysis, they ______ pH of the sample they are in
fatty acids, lower (will turn reddish because it is acidic)
What do bile salts do?
Break down fat
Fats break down in two steps:
1st step- Fats/oils break down into _________ due to the presence of _________.
minute fat/oil droplets, bile (emulsification)
Fats break down into two steps:
2nd step- fat/oil droplets break down into ________ and ________ due to the presence of _________
monoglycerides and fatty acids, lipase (digestion)
How can you tell when fat digestion is occurring or completed?
by testing the pH. When fat it digested it breaks down into fatty acids which lowers the pH of the solution it’s in. So by testing the pH, we are testing if digestion is occurring.
what color is Benedict’s solution? what is a positive benedict’s test?
Blue
+ test is orange for sugar(maltose)
What is the end product of Proteins?
Amino Acid
What is the end product of Carbohydrates?
Monosaccharides
What is the end product of fats?
Fatty acid and glycerol
Biologic catalyst; protein in nature
Enzyme
Used to test for protein hydrolysis, which was indicated by a yellow color
BAPNA
Used to test for the presence of starch, which was indicated by a blue-black color
Lugol’s Iodine (IKI)
Used to test for the presence of reducing sugars(maltose, sucrose, glucose) as indicated by a blue to green or orange color change
Benedicts solution
Starch + water ————->Maltose
What is needed to make this true?
Amylase
What color is IKI?
Brown
a + test is dark blue for starch
