BIO228lab - Digestive system/Metabolism
How many pairs of salivary glands do humans have?
3
Maltase
A digestive enzyme that breaks maltose into glucose ; synthesized by cells of the mucous membrane lining the intestinal wall ; ideal PH 7-7.5
Based upon your results of your Virtual Lab, "Digestion of Starch," why does a positive Benedict test result confirm that the unknown solution originally contained starch?
A positive result indicates simple sugars (maltose) that result from starch being digested by amylase.
Enzyme
A type of protein that speeds up a chemical reaction by lowering activation energy
What is the best pH for amylase activity?
Amylase works best at pH 7 but generates a little maltose at pH 2.
How do you interpret the Benedict test? What needs to happen in order to complete the Benedict test?
Benedict's solution contains copper, which can accept electrons from reducing sugars and consequently change color. A positive Benedict's sugar test will produce an orange to brick-red color. Used to discover glucose or starch.
What do you think would happen if you had boiled the amylase BEFORE you added it to the starch and incubated it at body temperature?
Boiling would denature the amylase (which is a protein and enzyme) so the amylase would no longer be able to catalyze the breakdown of starch. Thus, there would be no digestion of the starch and no maltose present at the end of the experiment.
Salivary Amylase
Enzyme in saliva that breaks down starch : PH 6-7
Pepsin
Enzyme produced by chief cells in the stimach, digests proteins in meats or dairy products ; had an ideal PH of 1.5-3
Chief Cells location
Gastric glands
Brunner's Glands location
Housed w/in submucosal layer, found only in the proximal duoderm
How does bile function in digestion?
It breaks down fats into fatty acids, which can be taken into the body by the digestive tract.
What is the purpose of making a maltose control solution?
It confirms that Benedict reagent produces an orange color in the presence of maltose.
List the three sections of the pharynx in order, from superior to inferior
Nasopharynx, oropharynx, laryngopharynx
Type of salivary gland that secretes from cheek
Parotid gland
Which salivary land makes mostly serous (protein) secretions?
Parotid salivary gland
Chief Cells function
Produce and secrete packets of zymogen granules primarily containing pepsinogen; also produce gastric lipase.
Chymotrypsin
Produced by pancreas ; breaks down proteins ; ideal PH 7-9
Pancreatic Amylase
Produced by pancreas ; continues digestion of complex sugars ; ideal PH 6-7
Pancreatic Lipase
Produced in pancreas ; breaks down fat ; ideal PH 7-7.5
Islet of langerhans function
Responsible for the production and release of hormones that regulate glucose levels
Sucrase
Secreted by tips of villi in small intestine ; breaks down sucrose ; ideal PH 6.2
What is the difference between TSH and TRH? Where are each of them produced?
TRH is thyrotropin-releasing hormone which stimulates the pituitary gland to release thyroid stimulating hormone (TSH). TRH is released by the hypothalamus.
How does the substrate for amylase differ from the substrate for lactase?How are the substrates similar?
The substrate of amylase is starch, a complex carbohydrate, whereas the substrate for lactase is lactose, a disaccharide ; The substrates are similar because they are both carbohydrates.
key point
Thyroid hormone is a key component in temperature regulation. Without thyroid hormone, the body must rely more on shivering for temperature regulation. This requires more oxygen consumption for ATP generation.
What effect do you think acclimation to cold would have on thyroxine production?
Thyroxine production should increase in colder temperatures
What is the purpose of making a control solution with starch and water at pH 7 but not including amylase?
To eliminate the possibility that starch is broken down into simple sugars by any other mechanisms than that of amylase.
What does "tropic" mean?
To turn on
Islet of langerhans function
Viscous, alkaline mucous that protects the duodenum from the acidic chyme entering the duodenum from the stomach
What is an emulsifier?
a molecule that can disperse fat in water
An exocrine substance produced by ____________ (acinar/islet) cells in the pancreas includes ____________________ (amylase/bicarbonate), which digests carbohydrates such as starch.
acinar,amylase
Trypsin
an enzyme from the pancreas that digests proteins in the small intestine ; ideal PH 7.5-8.5
The cecum is located at the beginning of the _______ colon.
ascending
catabolism
breaking down
Anabolism
building up
The two substances that are produced by the pancreas and released into the duodenum
digestive enzymes, bicarbonate
Three segments of the small intestine in order
duodenum, jejunum, ileum
Lactase
enzyme that breaks down lactose ; produced by brush border of small intestine ; ideal PH 6
The liver consists of how many lobes?
four
Peyer patches function
function in immune surveillance of materials in immune system
subunits of lipids
glycerol and fatty acids
What are the "building blocks" of triglycerides?
glycerol, fatty acids
Crypts of lieberkuhn location
intestinal glands
The endocrine part of the pancreas consists of acinar (acinar/islet) cells that produce pancreatic juice (hormones/pancreatic juice).
islet, hormones
Where is bile produced?
liver
Peyer patches location
lymphoid follicles in the mucus membrane that line your small intestine
Which of the following structure(s) increase(s) the total surface area of the small intestine?
microvilli and villi
Subunits of carbohydrates
monosaccharides
Glucose is a ______________ (monosaccharide/disaccharide/polysaccharide)
monosacharide
Carbohydrate site of digestion
mouth,small intestine
list the layers of the GI tract, from the most interior layer to the most exterior layer.
mucosa, submucosa, muscularis propia, adventia
Is bile an enzyme?
no
subunits of nucleic acids
nucleotides
Islet of langerhans location
pancreas
Both Pepsin and Trypsin are enzymes that breakdown proteins. Which one works best at a pH of 2? Which one works best at a pH of 7?
pepsin;trypsin
another name for circular folds
pilicae circulares
The esophagus is located _______ to the trachea
posterior
another name for gastric fold
rugae
Parietal cells function
secrete HCl and intrinsic factor
Crypts of lieberkuhn function
secrete digestive enzymes called carbohydrases - amylase, proteases, and lipases or fat splitting enzymes
Which of the following types of epithelial tissue lines the small and large intestine?
simple columnar with goblet cells and microvilli
Nucleic acid site of digestion
small intestine
Site of absorption for carbohydrates, lipids, nucleic acids, and proteins
small intestine
The presence of Peyer Patches is unique to the ______________.
small intestine ileum
Based upon your results of your Virtual Lab, "Emulsification of Lipids," which of the following is a substance that causes emulsification that you might encounter in everyday life?
soap
Parietal cells location
stomach
Lipid site of digestion
stomach, small intestine
Protein site of digestion
stomach, small intestine
What type of epithelial lining will you find in the esophagus?
stratifies squamous epithelium
basal metabolic rate
the body's resting rate of energy expenditure (no eating and must rest prior to measuring this); energy cost of living... the rate at which energy is used (heat produced) by the body per unit of time under controlled conditions
List the 4 parts of the colon in order (as materials would normally pass through them):
transverse, descending, sigmoid portions of colon, rectum
BAPNA
used to test for protein hydrolysis, which was indicated by a yellow color
litmus
used to test for the presence of fatty acids, which was evidenced by a color change from blue to pink
Benedict's solution
used to test for the presence of reducing sugars (maltose, sucrose, glucose) as indicated by a blue to green or orange color change
Lugol's iodine (IKI)
used to test for the presence of starch, which was indicated by a blue-black color
