MED ORG LAB exp 3

Experiment 3

CHEMICAL DIGESTION OF NUTRIENTS

process by which large, complex food molecules are broken down into smaller, absorbable units through the action of enzymes and other digestive chemicals.

Chemical digestion

Chemical digestion process occurs primarily in the

stomach and small intestine

Process of carbohydrates in the ___: ___ begins the breakdown of ___ into ___.

mouth

Salivary amylase

starches

maltose

Process of carbohydrates in the ___: ___ continues the breakdown of starches into maltose and other ___. Enzymes like ___ further break down disaccharides into monosaccharides (___).

small intestine

Pancreatic amylase

disaccharides

maltase, sucrase, and lactase

glucose, fructose, and galactose

Process of proteins in the ___: ___, activated by the ___ environment, starts breaking down proteins into smaller ___.

stomach

Pepsin

acidic

polypeptides

Process of proteins in the ___: ___ like ___ and ___further break down polypeptides into smaller ___. ___ on the ___ then break these peptides into ___.

small intestine

Pancreatic enzymes

trypsin

chymotrypsin

peptides

Peptidases

intestinal lining

amino acids

Process of fats (lipids) in the ___: ___ from the ___ emulsify fats, increasing their surface area. ___ then breaks down ___ into ___ and ___.

small intestine

Bile salts

liver

Pancreatic lipase

triglycerides

free fatty acids

monoglycerides

These smaller molecules of fats (lipids) are then absorbed through the ___ into the ___, where they are transported to ___ for ___.

intestinal walls

bloodstream

cells

energy, growth, and repair

what are the solutions added in the 4 test tubes of carbohydrate

Add 5 mL of starch solution to each test tube.

Tube 1: 3 mL water

Tube 2: 3 mL amylase solution

Tube 3: 3 mL amylase solution and 10 drops of HCl solution

Tube 4: 3 mL amylase solution, then place tube in boiling water for 5 minutes

where are the 4 test tubes placed to incubate?

37°C water bath for 1 hour

after incubation, the 4 test tubes are split into two sets, what is the solution that set 1 and 2 will be tested upon?

undigested starch (Lugol's test)

maltose (Benedict's test)

How many drop of Lugol’s test is added and what is the reagent

few drops of Lugol's iodine solution

Lugol’s test color interpretation

amber (like the Lugol's reagent), no starch present (-)

blue or black, starch is present (+)

How many drop of Benedict’s test is added and what is the reagent

5 mL of Benedict's reagent and place the tubes in boiling water for 10 minutes

Benedict’s test color interpretation

blue, no maltose is present (-)

green, a small amount of maltose is present (+)

yellow, a moderate amount of maltose is present (+++)

orange or red, a large amount of maltose is present (+++)

For the digestion of proteins, what are added to the 5 test tubes

small slice of hard-boiled egg white to each of the five tubes

Tube 1: Add 5 mL of pepsin solution and 10 drops of water

Tube 2: Add 5 mL of pepsin solution and 10 drops of HCl

Tube 3: Add 5 mL of pepsin solution and 10 drops of HCl, then place on ice.

Tube 4: Add 5 mL of water and 10 drops of HCl

Tube 5: Add 5 mL of pepsin solution and 10 drops of NaOH.

Place tubes 1, 2, 4, and 5 in a 37C water bath to incubate for 90 minutes

for the chemical digestion of fats, what are added to the 3 test tubes

ADD 3 ML OF HEAVY CREAM TO EACH TUBE

Tube 1: 5 mL of water and a few grains of bile salts

Tube 2: 5 mL pancreatin solution

Tube 3: 5 mL pancreatin and a few grains of boil salts

shake vigorously then measure initial pH

for the chemical digestion of fats, the initial pH of each solution is measured with the probe of a ___, cleaning off the probe in ___ and rinsing with ___ between each measurement.

pH meter

detergent

distilled water

for the chemical digestion of fats, what is done after measuring the initial pH?

place the tubes into the 37°C water bath for incubation

for the chemical digestion of fats, what is done after incubation?

Repeat pH measurements of each solution at 20 mi, 40 min, and 60 min after the beginning of the incubation

breaks down complex carbohydrates such as ___ into ___, mainly ___, by ___. This begins carbohydrate digestion and facilitates further breakdown into absorbable monosaccharides.

Amylase

starch

smaller sugars

maltose

hydrolyzing glycosidic bonds

The hormone ___ lowers ___ by promoting glucose uptake into ___ and storage as ___. When blood glucose falls, ___ stimulates the release of stored glucose from the ___ to maintain normal levels.

insulin

blood glucose

cells

glycogen

glucagon

liver

___ is a gastric enzyme that breaks proteins into smaller ___ by hydrolyzing ___. It functions optimally in the ___ environment of the stomach

Pepsin

polypeptides

peptide bonds

acidic

____ and ___ further digest ___ in the small intestine into smaller peptide fragments. These fragments are then broken down into ___ by ___ for absorption

Trypsin

chymotrypsin

polypeptides

amino acids

intestinal peptidases

___ emulsify fats into small droplets, increasing surface area for enzyme action and improving lipid digestion efficiency. However, they do not chemically digest fats

Bile salts

___ breaks ___ into fatty acids and monoglycerides for absorption in the ___.

Pancreatic lipase

triglycerides

small intestine