Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Biochem Fall > Chapter 11- Imi Biochem > Flashcards

Chapter 11- Imi Biochem Flashcards

1
Q

what is digestion

A

hydrolysis of complex food substances into simple units such as monosaccharides, amino acids, fatty acids, and glycerol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what is absorption

A

transport of the products of digestion and of vitamins, minerals, and water across the intestinal epithelium to the lymphatic or blood circulatory systems

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what is digestion and absorption

A

GI tract, secretions from salivary glands, liver and gall bladder, and pancreas that are interrelated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Secretory and absorptive activities are regulated by

A

hormones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

intestinal surface area enhanced by

A

finger-like villi

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

GI Tract Is controlled by

A

Central Nervous System and the Enteric Nervous System

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

2 plexus of GI system

A

submucosal and myenteric nerve plexus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

function of mouth

A

mixed with saliva, chewed to break up large particles, propelled into esophagus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

saliva secretes, tonicity of solution, pH, principle ions, modulation

A

1-2L secreted daily, hypotonic solution (pH 7.0), principle ions (Na+, K+, Cl-, HCO3-), aldosterone modulate Na+ & K+ levels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

mucin function, composition

A

responsible for lubricating action, mixture of glycoproteins containing 60-85% oligosaccharides by weight

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Amylase function

A

catalyze the hydrolysis of α(1-4) glycosidic linkages of starch and glycogen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

other enzymes secreted from the mouth

A

Carbonic anhydrase, lipase, phosphatase, protease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

esophagus

A

a muscular tube, has no digestive function but secrete mucus to protect the esophageal mucosa from excoriation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

stomach

A

Store food temporarily, retards its entry into SI

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

pepsin

A

secreted by stomach, substantial chemical and enzymatic digestion is initiated, particularly of proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

formation of pepsin

A

[H+] activate pepsinogen to form pepsin, aid in maintaining the sterility of upper GI tract

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

stomach also secretes

A

intrinsic factor, lipase, gelatinase, chymosin (rennin), mucus, HCl, Gastrin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

pH of stomach prevents

A

pH is so low prevents bacterial survival except H. pylori (survives at pylorus)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

intrinsic factor required to absorb what, where

A

vitamin B12 in the ileum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Most digestion and absorption of food constituents occurs in the

A

Small intestine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

small intestine major site for

A

absorption of water & electrolytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

parts of small intestine

A

duodenum, jejunum, ileum,

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Wall of small intestine consists of

A

4 layers: mucosa, submucosa, muscularis externa, serosa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

villi, enterocyte, microvilli allow for what and appearance

A

large surface area, increase the absorptive surface, a brush like appearance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

digestion in small intestine require

A

biliary & pancreatic secretions that are emptied into the duodenum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Bile is formed and secreted continuously by

A

polygonally shaped liver parenchymal cells called hepatocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

bile is concentrated, stored, emptied into the duodenum by

A

gallbladder

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

composition of bile

A

Contains bile acids, bile pigments, cholesterol (gallstones), phosphatidylcholine, & electrolytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

contraction of gallbladder mediated by

A

cholecystokinin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

mechanism of bile synthesis

A

senescent red cell broken down -> bilirubin -> added to albumin ->forming free bilirubin in hepatocyte -> addition of glucuronic acid -> conjugated bilirubin -> bile formation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Endocrine function of pancreas

A

secrete insulin, glucagon, somatostatin for regulation of metabolism of CHOs and other substances

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Exocrine function fo pancreas

A

synthesis & secretion of digestive enzymes and bicarbonate-rich fluids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

digestive enzymes and bicarbonate rich fluids from pancreas released into lumen upon

A

stimulation by the vagus nerve or by cholecystokinin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

pH of pancreatic juice

A

Alkaline b/c high content of HCO3-

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

pancreatic juice are alkaline to

A

neutralize acidic chyme from the stomach aided by the bile & SI juices

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

pancreatic juice contain

A

proenzymes trypsynogen, chymotrypsinogen, procarboxypeptidases, & proelastase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

proenzymes trypsynogen, chymotrypsinogen, procarboxypeptidases, & proelastase activated by

A

activated by trypsin in the intestinal lumen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

trypsin activated by

A

trypsinogen converted to trypsin by enteropeptidase located in the brush border of the jejunal mucosa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

pancreatic juice contains trypsin inhibitor to

A

protect against indiscriminate autodigestion from intraductal activation of trypsinogen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Other enzymes of pancreatic juice are

A

prophospholipase, cholesteryl ester hydrolase, lipase and procolipase, amylase, ribonuclease, deoxyribonuclease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

major function of large intestine

A

absorption of water, Na+, & other electrolytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

large intestine harbors large numbers of anaerobic bacteria to

A

metabolize CHOs to lactate, short-chain fatty acids (acetate, propionate, butyrate), & gases (CO2, CH4, & H2)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

gastrointestinal hormones are

A

Chemical messengers that regulate intestinal functions (e.g., motility and secretion- autonomic nervous system also regulates)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

Endocrine cells of the GI tract are interspersed with

A

mucosal cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

GI tract is described as the

A

largest endocrine organ in the body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

Major GI hormone

A

gastrin ghrelin, cholecystokinin, glucose dependent insulinotropic polypeptide (GIP), secretin, polypeptide YY, somatostatin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

gastrin source and function

A

Source: G-cells of gastric antrum and duodenum Function: stimulates acid (HCl) secretion from parietal cells and histamine from enterochromaffin-like cells; promotes proliferation of gastric mucosa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

ghrelin source and function

A

Source: A-cells of gastric fundus; other segments of GI tract; hypothalamus Function: promote food intake, gastric motility; stimulates growth hormone secretion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

cholecystokinin source and function

A

Source: I-cells of duodenum and jejunum; central nervous system Function: stimulates gall bladder and pancreatic enzyme secretions; decreases appetite

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

glucose dependent insulinotropic polypeptide (aka Gastric inhibitory peptide-GIP) source and function

A

Source: K-cells of the duodenum and jejunum Function: promote insulin secretion from beta-cells of pancreas (incretin effect); FA synthesis in adipose tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

secretin source and function

A

Source: S-cells of the duodenum and jejunum also present in brain Function: stimulates the secretion of bicarbonate-rich fluids from the duct cells and biliary tract; augments the action of CCK and decreases gastric acid secretion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

polypeptide YY source and function

A

Source: L-cells of distal small and large intestine Function: inhibits food intake

53
Q

somatostatin source and function

A

Source: D-cells of the GI tract and pancreas; hypothalamus Function: inhibits secretion of GI tract hormones, growth hormone, and thyrotropin

54
Q

GI hormones obtained from proglucagon cleavage by cell-specific pro hormone convertases

A

glucagon-like peptide 1 (GLP-1), glucagon-like peptide 2 (GLP-2), Oxyntomodulin

55
Q

glucagon-like peptide 1 (GLP-1) source and function

A

Source: L-cells of distal small and large intestine Function: promotes insulin secretion from beta cells of pancreas (incretin effect) and promotes beta-cell growth; suppresses pancreatic glucagon secretion by alpha-cells; delays gastric emptying

56
Q

glucagon-like peptide 2 (GLP-2) source and function

A

Source: L-cells of distal small and large intestine Function: promotes intestinal mucosal growth and repair; inhibits gastric secretion

57
Q

Oxyntomodulin source and function

A

Source: L-cells of distal small and large intestine Function:inhibits food intake; inhibits gastric motility and acid production

58
Q

precursor to glucagon

A

proglucagon

59
Q

proglucagon goes to

A

pancreatic alpha-cells, brain, L-intestinal cells

60
Q

gastrin secreted from and function

A

Secreted from the stomach and plays an important role in control of gastric acid secretion

61
Q

gastrin released in response to

A

chemical, mechanical, or neural stimuli on the G cell Hypoglycemia, increased calcium ions

62
Q

main physiological actions of gastrin

A

Stimulation of acid secretion by parietal cells, Secretion of pepsin by chief cells, Increase in gastric mucosal blood flow, Stimulation of gastric motility, Promotion of the growth of oxyntic mucosa and exocrine pancreatic tissue

63
Q

gastrin is suppressed by

A

acidification of the antral mucosa & by all members of the secretin family

64
Q

when H+ not secreted owing to destruction or absence of functioning parietal cells leads to

A

increased plasma gastrin levels

65
Q

increased plasma gastrin levels causes

A

pernicious anemia, atrophic gastritis, Zollinger-Ellison syndrome

66
Q

hyper secretion of acid, peptic ulcer disease, and hyperplasia of gastric mucosa are attributed to

A

Zollinger-Ellison syndrome

67
Q

If Intracellular pH 7, luminal pH 1 parietal cells secrete

A

H+ at a concentration a million-fold higher than that inside the cell, contain the largest number of mitochondria

68
Q

HCl is secreted into the gastric lumen by

A

H+, K+-ATPase, HCO3- is secreted into blood

69
Q

what stimulates acid secretion from parietal cell

A

Acetylcholine, gastrin, histamine (H2 receptor), & bombesin

70
Q

Secretion of gastric acid is suppressed by

A

anticholinergic agents (atropine), H2 receptor antagonists (cimetidine, ranitidine), prostaglandin E derivatives, substituted benzimidazoles (omeprazole, pantoprazole)

71
Q

second messengers in acid secretion from parietal cells

A

cAMP (H2 receptor coupled to Adenyl Cyclase) & Ca2+ (cholinergic receptor coupled)

72
Q

parietal cells secrete

A

H+ and Cl-

73
Q

peptic ulcer disease caused by

A

an imbalance of acid secretion by the parietal cells and lack of mucosal protective barriers due to drug (NSAIDs) or bacterial infection (Helicobacter pylori)

74
Q

NSAIDs inhibit

A

COX1 and COX2

75
Q

celecoxib, cytoprotective effects by misoprostol

A

COX 2 inhibitors

76
Q

H. pylori treated with

A

antibiotics, anti-secretory agents (H2-Receptor antagonists or proton pump inhibitors), & bismuth salts

77
Q

H. pylori produces bacterial urease that does what

A

urea converted to ammonia and CO2 causing increased pH which increase levels of gastrin and increases acid production

78
Q

H. pyroli also produce vacuolating cytotoxin and CagA that causes

A

ulcerogenesis, gastritis and a risk factor for adenocarcinoma of the antrum and the body of the stomach & non-Hodgkin’s lymphoma of the stomach

79
Q

H. pylori detected by

A

serological markers and breath test

80
Q

cholecystokinin secreted as a result of

A

stimuli caused by products of digestion of proteins and lipids

81
Q

cholecystokinin secretion terminated when

A

digestion products are absorbed or migrate into the lower portions of the GI tract

82
Q

principal physiological actions of cholecystokinin

A

stimulate gallbladder contraction, to relax the sphincter of Oddi, and to stimulate secretion of pancreatic juice rich in digestive enzymes

83
Q

other functions of cholecystokinin

A

stimulate bicarbonate-rich fluid secretion, insulin secretion, and intestinal motility

84
Q

stimulates release of secretin

A

Chyme in the duodenum

85
Q

A.a. sequence of secretin is similar to

A

glucagon, vasoactive inhibitory peptide (VIP), and gastric inhibitory peptide (GIP)

86
Q

Secretin hormone action

A

mediated by membrane-bound adenylate cyclase and increased intracellular cAMP

87
Q

Gastric inhibitory peptide stimulated by

A

glucose and lipids in the duodenum

88
Q

main functions of gastric inhibitory peptide

A

stimulate insulin secretion that prepares the appropriate tissues for the transport and metabolism of nutrients obtained from the GI tract, and inhibit gastric secretion and motility

89
Q

incretin promote

A

insulin secretion

90
Q

incretins are

A

glucagon-like peptide 1 and gastric inhibitory peptide

91
Q

Predominant digestible CHOs are

A

starches (amylose & amylopectin), glycogen, disaccharides (sucrose & lactose)

92
Q

Intraluminal hydrolysis of starch and glycogen by

A

α-amylase to oligosaccharides of variable length and structure

93
Q

oligosaccharidases

A

Brush-border surface hydrolysis of oligosaccharides and disaccharides (e.g., sucrose, lactose, & trehalose) to their monomers

94
Q

Intolerance of other carbohydrates

A

sucrose and α-limit dextrin

95
Q

Transport of monosaccharides (e.g., glucose, galactose, & fructose) into enterocytes

A

Na+, K+-ATPase

96
Q

alpha amylase cleaves

A

alpha (1-4) linkage

97
Q

stomach secretes

A

pepsinogen

98
Q

pancreas secretes

A

trypsin, chymotrypsin, carboxypeptidase, elastase

99
Q

Brush-border secretes

A

aminopeptidase, dipeptidase, tripeptidase

100
Q

endogenous proteins promote

A

Enzymes, glycoproteins, and mucins secreted from the salivary glands, stomach, intestine, biliary tract, and pancreas (20-30g/day) Rapid turnover of the GI epithelium (30g/day) Plasma proteins that normally diffuse into the intestinal tract at a rate of 1-2g/day

101
Q

free a.a. transported into enterocytes by what four active, carrier-mediated, Na+-dependent transport systems

A

Neutral a.a.; basic a.a. (Lys, Arg, His) & cystine; Asp & Glu; Gly & Imino acids

102
Q

a few days after birth neonates have ability to absorb

A

intact proteins

103
Q

by absorbing intact proteins neonates can acquire

A

passive immunity by absorbing Igs in colostral milk

104
Q

defects in neutral amino acid transport

A

hartnup’s disease

105
Q

defect in basic a.a. and cysteine transport

A

cystinuria

106
Q

defect in asp and glutamate (carboy group) transport

A

dicarboxylic aminoaciduria

107
Q

cyanogenbromide cleaves

A

methionine at c-terminus

108
Q

defect in transport of glycine

A

aminoglycinuria

109
Q

trypsin cleaves

A

arginine and lysine at c-terminus

110
Q

chymotrypsin cleaves

A

tryptophan, tyrosine, and phenylalanine

111
Q

to determine pancreatic problem admin N-benzoyl-L-tyrosyl-p-aminobenzoic acid

A

check urine for PABA, if no PABA chymotrypsin not working

112
Q

Hydrolysis of triglyceride into monoglyceride and free fatty acids is accomplished predominantly by

A

pancreatic lipase

113
Q

steatorrhea

A

more than 90% of ingested lipid not absorbed

114
Q

Gluten-sensitive enteropathy or celiac disease

A

gliadins leads to production of Ab to endomysium of smooth muscle

115
Q

Cyctic fibrosis (CF)

A

a disease of multiple exocrinopathy and generalized malabsorption due to lack of delivery of pancreatic digestive enzymes to the small intestine

116
Q

chronic alcoholism

A

generalized malabsorption of major foods and vitamins b/c of liver and pancreatic involvement and mucosal dysfunction

117
Q

cholera secretes ZOT toxin which effects

A

tight junctions, zonula occludens toxin

118
Q

diarrhea

A

water excreted in feces greater than 500mL

119
Q

treatment for diarrhea

A

oral glucose and NaCl

120
Q

Na+ absorption regulated by

A

aldosterone

121
Q

K+ absorbed by

A

passive diffusion

122
Q

If the intestinal contents become hyperosmolar then

A

water enters the lumen to produce iso-osmolarity and fluid and electrolyte loss occur

123
Q

Bile salts in colon inhibit absorption of

A

water and Na+ and cause diarrhea

124
Q

ADP-ribosylation of Gsα

A

cholera toxin

125
Q

cholera toxin mechanism

A

ADP-ribosylation of Gsalpha -> activates adenyl cyclase -> increases cAMP -> continuous stimulation of CFTR Cl- channel -> increased osmolarity in intestinal lumen -> passive water excretion -> diarrhea

126
Q

ADP-ribosylation of Giα

A

pertussis toxin

127
Q

E. Coli

A

non-bloody diarrhea, hemorrhagic colitis, hemolytic uremic syndrome, death

128
Q

diphtheria toxin

A

ADP-ribosylation, inhibit (elongation factor) eukaryotic protein synthesis

129
Q

pancreatic islet-cell tumor causes

A

severe watery diarrhea

Biochem Fall (13 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions