lab 39- Digestion

Question 1

Enzymes are _______ that increase the rate of chemical reactions without becoming a part of the product

Answer 1

catalysts

Question 2

True or False:

When you use iodine to test for starch, a color change to blue-black indicates a positive starch test

Answer 2

true

Question 3

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.

Answer 3

salivary amylase

Question 4

If Benedict’s test in the starch assay produces a ___________ precipitate, then your test will be recorded as positive for maltose.

Answer 4

green to orange

Question 5

The enzyme ___________ , produced by the pancreas, is responsible for breaking down proteins.

Answer 5

trypsin

Question 6

The enzyme ___________ hydrolyzes neutral fats to their component monoglycerides and fatty acids

Answer 6

pancreatic lipase

Question 7

True or false:

Both smooth and skeletal muscles are involved in the physical processes of digestion

Answer 7

true

Question 8

___________ movements are local contractions that mix foodstuffs with digestive juices and increase the rate of absorption

Answer 8

segmental

Question 9

What are substrates?

Answer 9

The molecules on which enzymes act on (in this experiment substrates are the food molecules)

Question 10

Digestive enzymes are also called ________

Answer 10

hydrolases

Question 11

How to substrates break down into monomers?

Answer 11

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

Question 12

The two enzymes involved in starch digestion are ________ and ________

Answer 12

salivary amylase and pancreatic amylase

Question 13

Starch breaks down into ________ by ________

Answer 13

maltose by salivary amylase

Question 14

The experiment must have ________ to provide a standard against which comparisons can be made.

Answer 14

controls

Question 15

IKI tests the solution for ________

Answer 15

starch

Question 16

When IKI i sadded to a solution a blue-black color indicates the presence of ________ and is called a ________

Answer 16

starch, positive starch test

Question 17

If the solution turns orange after IKI is added this is a ________

Answer 17

negative starch test

Question 18

What indicates a positive sugar test?

Answer 18

When the solution turns orange after Benedict’s solution is added

Question 19

If the solution turns blue after adding Benedict’s solution this is a ________

Answer 19

negative sugar test (Benedict’s solution is blue)

Question 20

Trypsin breaks down ________

Answer 20

proteins

Question 21

Trysin is produced by the ________

Answer 21

pancreas

Question 22

BAPNA is a ________

Answer 22

color indicator (goes from colorless to bright yellow if protein is broken down into amino acids

Question 23

If the solution turns yellow when BAPNA is present this indicates a _____________

Answer 23

positive hydrolysis test (amino acids are present)

Question 24

What color will the solution be if a negative hydrolysis occurs when BAPNA is added?

Answer 24

no color change

Question 25

Why would a benedict’s solution turn green?

Answer 25

Because it’s in between changing from orange to blue-black, maybe you didn’t wait long enough for the glucose chain to denature

Question 26

Litmus powder indicators detect __________

Answer 26

pH

Question 27

Alkaline or neutral solutions turn litmus _____________

Answer 27

blue

Question 28

Acidic solutions turn litmus ___________

Answer 28

reddish

Question 29

Since fats are digested to ________ during hydrolysis, they ______ pH of the sample they are in

Answer 29

fatty acids, lower (will turn reddish because it is acidic)

Question 30

What do bile salts do?

Answer 30

Break down fat

Question 31

Fats break down in two steps:

1st step- Fats/oils break down into _________ due to the presence of _________.

Answer 31

minute fat/oil droplets, bile (emulsification)

Question 32

Fats break down into two steps:

2nd step- fat/oil droplets break down into ________ and ________ due to the presence of _________

Answer 32

monoglycerides and fatty acids, lipase (digestion)

Question 33

How can you tell when fat digestion is occurring or completed?

Answer 33

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.

Question 34

what color is Benedict’s solution? what is a positive benedict’s test?

Answer 34

Blue

+ test is orange for sugar(maltose)

Question 35

What is the end product of Proteins?

Answer 35

Amino Acid

Question 36

What is the end product of Carbohydrates?

Answer 36

Monosaccharides

Question 37

What is the end product of fats?

Answer 37

Fatty acid and glycerol

Question 38

Biologic catalyst; protein in nature

Answer 38

Enzyme

Question 39

Used to test for protein hydrolysis, which was indicated by a yellow color

Answer 39

BAPNA

Question 40

Used to test for the presence of starch, which was indicated by a blue-black color

Answer 40

Lugol’s Iodine (IKI)

Question 41

Used to test for the presence of reducing sugars(maltose, sucrose, glucose) as indicated by a blue to green or orange color change

Answer 41

Benedicts solution

Question 42

Starch + water ————->Maltose

What is needed to make this true?

Answer 42

Amylase

Question 43

What color is IKI?

Answer 43

Brown

a + test is dark blue for starch