Lab: Digestive Chemicals Flashcards
1
Q
Substance on which a catalyst works
A
Substrate
2
Q
Biologic catalyst protein in nature
A
Enzyme
3
Q
Increases the rate of a chemical reaction without becoming part of the product
A
Catalyst
4
Q
Provides a standard of composition for test results
A
Control
5
Q
List three characteristics of enzymes
A
- substrate specific
- temperature specific
- pH specific
6
Q
The enzymes of the digestive system are classified as hydrolases. What does this mean
A
Hydrolases breaks down organic food molecules by adding water to the molecular bonds to cleave them
7
Q
Salivary amylase is produced by what organ
A
Salivary gland
8
Q
Site of action for salivary amylase
A
Oral cavity or mouth
9
Q
Substrate of salivary amylase is
A
Starch
10
Q
Optimal pH of salivary amylase is
A
6.7-7.0
11
Q
Trypsin is produced by what organ
A
Pancreas
12
Q
Site of action for trypsin is
A
Small intestine
13
Q
Substrate of trypsin
A
Proteins
14
Q
Optimal pH of trypsin
A
8.0
15
Q
Lipase is produced by what organ
A
Pancreas
16
Q
Site of action for lipase is
A
Small intestine
17
Q
Substrates of lipase are
A
Fats and proteins
18
Q
Optimal pH of lipase is
A
7.4-8.0
19
Q
The end products of proteins are
A
Amino acids
20
Q
The end products of fats are
A
Fatty acids and glycerol
21
Q
The end products of carbohydrates are
A
Simple sugars glucose
22
Q
How does the substrate for amylase differ from the substrate for lactase
A
Substrate of amylase is starch polysaccharides and substrate of lactase is disaccharides
23
Q
How is the substrate for amylase similar to the substrate for lactase
A
Site of action is small intestine for both carbohydrates
24
Q
Where does lactose hydrolysis occur for lactase-persistent individuals
A
Small intestines
25
Where does lactose hydrolysis occur for lactose-intolerant individuals who have consumed probiotic bacterial microflora
Large intestine
26
BAPNA
Used to test for protein hydrolysis which was indicated by a yellow color
27
Lugol's iodine
Used to test for the presence of starch which was indicated by blue-black color
28
Litmus
Used to test for the presence of fatty acids which was evidenced by a color change from blue to pink
29
Benedict's solution
Used to test for the presence of reducing sugars maltose, sucrose, glucose as indicated by a blue to green or organge color change
30
What conclusions can you draw when an experimental sample gives both a positive starch test and a positive maltose test after incubation
Starch digestion is partial into maltose
31
Why was 37 degrees C the optimal incubation temperature
It is body temperature
32
Trypsin is a protease similar to pepsin the protein digesting enzyme in the stomach. Would trypsin work well in the stomach why
No because the pH for trypsin is slightly basic the pH optimum for pepsin is acidic
33
What role does bile play in fat digestion
Emulsification of fat by bile increases the surface area for lipase activity
34
Assume you have been chewing a piece of bread for 5 to 6 minutes how would you expect it's taste to change during this interval why
The bread would begin to taste sweet because starch is broken down to glucose by amylase
35
Mechanism of absorption for monosaccharides
Passive transport
36
Mechanism of absorption for fatty acids and monoglycerides
Active transport
37
Mechanism of absorption for amino acids
Active transport
38
Mechanism of absorption for water
Osmosis passive transport
39
Mechanism of absorption for Na+, Cl-, Ca2+
Na+ Ca2+ active transport. Cl- diffusion
40
Secretin is produced by
Duodenal mucosa
41
Target organs and effects of secretin are
1. pancreas secretes bicarbonate liquid buffer
| 2. liver secretes bile
42
Gastrin is produced by
1. Stomach mucosa
| 2. Duodenum
43
Target organs and effects of gastrin are
Gastrin acts on the stomach glands to increase their secretory activity
44
Cholecystokinin is produced by
Intestinal cells of duodenum
45
Target organs and effects of cholecystokinin
1. production of bile by liver and juice mix by pancreas
2. gallbladder contraction to release bile
3. inhibits gastric secretion
46
Swallowing or
Deglutition
47
Two phases of deglutition are
1. Buccal phase (voluntary)
| 2. pharyngeal-esophageal phase (involuntary)
48
Which phase of deglutition is voluntary
Buccal
49
What happens during the buccal phase
The tongue is used to push the food into the back of the throat
50
During swallowing the larynx
Rises to ensure that it's passageway is covered by the epiglottis so that the ingested substances don't enter the respiratory passageways
51
It is possible to swallow water while standing on your head because
The water is carried along the esophagus involuntarily by the process of peristalsis
52
The gastroesophageal sphincter
The pressure exerted by the foodstuffs on this sphincter causes it to open allowing the foodstuffs to enter the stomach
53
The two major types of propulsive movement that occur in the small intestine are
Peristaltic and segmental
54
Segmental movement acts to
Continuously mix the foods and to increase the absorption rate by moving different parts of chyme mass over the intestinal mucosa but it has less of a role in moving foods along the digestive tract
55
What are the major functions of the mucosa
Major Functions: Secretion, absorption, protection
56
What are the subdivisions of the mucosa
Surface epithelium, Lamina propria, muscularis mucosa
57
What are the major functions of the submucosa
Nutrition, Protection
58
What are the subdivisions of the submucosa
None
59
What are the major functions of the Muscularis externa
Regulator of GI motility.
60
What are the subdivisions of the Muscularis externa:
Smooth muscle Inner/Outer Layers
61
What are the major functions of the serosa or adventitia
Major Functions: Anchors, protects, and reduces friction.
62
What are the subdivisions of the Serosa or adventitia
Visceral peritoneum, mesothilium, adventita.
63
The tubelike digestive system canal that extends from the mouth to the anus is known as the _______ canal or the ________ tract.
alimentary; digestive
64
What transition in epithelial type exists at the gastroesophageal junction.
Squamous cells in the esophagus to columnar cell in the gastral mucosa.
65
Differentiate the colon from the large intestine.
Large intestine extends from the ileocecal valve to the anus, but colon is part of the large intestine and divided into ascending, descending, and sigmoid colon.
66
Conduit for both air and food?
Pharynx
67
Fingerlike extensions of the intestinal mucosa that increase the surface area for absorption.
Villi
68
Large collections of lymphoid tissue found in the submucosa of the small intestine.
Peyer's patches
69
Region containing two sphincters through which feces are expelled from the body?
Anus
70
Wormlike sac that outpockets from the cecum?
Appendix
71
The "gullet"; no digestive/absorptive function?
Esophagus
72
Membrane securing the tongue to the floor of the mouth?
Frenulum
73
Covers most of the abdominal regions like an apron?
Greater omentum
74
Bone-supported anterosuperior boundary of the oral cavity?
Hard palate
75
Valve at the junction of the small and large intestines?
Ileocecal valve
76
Structure attached to the lesser curvature of the stomach?
Lesser omentum
77
Valve controlling food movement from the stomach into the duodenum?
Pyloric valve
78
Folds of the gastric mucosa?
Rugae
79
Primary region of food and water absorption?
Jejunum
80
Posterosuperior boundary of the oral cavity?
Soft palate
81
Initiates protein digestion?
Stomach: pepsin
82
Produces mucus; found in the submucosa of the small intestine.
Duodenal glands
83
Produces a product containing amylase that begins the starch breakdown in the mouth.
Salivary glands
84
Produces many enzymes and an alkaline fluid that is secreted into the duodenum.
Pancreas
85
Produces bile that it secreted into the duodenum via the bile duct.
Liver
86
Found in the mucosa of the small intestine; produces intestinal juice.
Intestinal crypts.
87
What is the role of the gallbladder
The gallbladder holds bile produced in the liver until it is needed for digesting fatty foods in the duodenum of the small intestine.
88
The pancreas has two major populations of secretory cells - those in the islets and the acinar cells. Which population serves the digestive process?
Acinar cells
89
What do parietal cells excrete?
hydrochloric acid (HCl) and intrinsic factor.
90
Where are parietal cells located?
the gastric glands found in the lining of the fundus and cardia of the stomach.
91
What do chief cells excrete?
pepsin
92
Where are chief cells located?
deep in the mucosal layer of the stomach lining
93
What are the 3 salivary glands?
Lingual, Submandibular + Parotid
94
What are lacteals?
Special lymphatic vessels of the small intestine which absorb digested fatty acids in the form of chylomicrons
