Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
34 Cards in this Set
- Front
- Back
what is faster channel mediated or carrier mediated?
|
channel mediated
|
|
why is carrier mediated slower?
|
requires a conformational change
|
|
Specialized proteins that facilitate the transport of larger, hydrophilic (polar) molecules across the plasma membrane?
|
carrier proteins
|
|
-help form the active site through a conformation change of the enzyme or help in enzyme- substrate binding.
- are metal ions (Ca2+, Mg2+, Mn2+, Cu2+, Zn2+) |
Cofactors
|
|
-transport hydrogen atoms and other small molecules between enzymes
-are organic molecules derived from water-soluble vitamins. |
Coenzymes
|
|
swallowing is also knowns as?
|
Deglutination
|
|
Segmentation?
|
churning/mixing
|
|
Immunity of the GI tract is d/t ______ ______ epithelium with ______junctions prevents swallowed pathogens from entering body.
|
-Simple columnar
-tight junctions |
|
digestion of carbs begins?
|
in the mouth
|
|
are carbs digested in the stomach?
|
not really
|
|
digestion of proteins begins in the?
|
stomach
|
|
2 functions of goblet cells?
|
-Secrete mucous
-Protects against autodigestion of epithelium |
|
Function of Chief Cells
|
-Secrete pepsinogen (inactive enzyme)
-Activated to pepsin by HCl- and by pepsin itself (positive feedback mechanism) |
|
Function of parietal cells?
|
secrete HCl and intrinsic factor
|
|
Intrinsic factor
|
Glycoprotein required for absorption of vitamin B12 in small intestine.
|
|
lipid digestion begins
|
in the small intestine
|
|
Villi?
|
-Motile fingerlike extensions (~1mm high) of the mucosa
-Simple columnar epithelium and goblet cells |
|
Microvilli
|
-Projections (brush border) of absorptive cells
-Contain brush border enzymes, which remain in the villi |
|
Do brush border enzymes enter the lumen?
|
no
|
|
Order of events in lipid breakdown?
|
1 - emulsification of fat droplets by bile salts
2 - hydrolysis of triglycerides in emulsified fat droplets into fatty acid and monoglycerides 3 - dissolving of fatty acids and monos into micelles |
|
Absorption of water, electrolytes, vitamin K, and some B vitamins occurs?
|
in large intestine
|
|
Microflora are necessary for synthesis of various essential nutrients:
|
vitamin B
vitamin K Folic Acid |
|
how much digestion occurs in the large intestine?
|
none
|
|
Invertase catalyzes the breakdown of ________ into ______ and ______.
|
sucrose into glucose and fructose
|
|
glucose and fuctose are?
|
reducing sugars
|
|
Reducing sugars reduce what reagent to what product
|
-3,5-Dinitrosalicylate (DNS) to aminonitrosalicylate (ANS).
|
|
the invertase reduction results in what color change?
|
The reduction of DNS to ANS can be detected as a color change from a bright yellow (DNS) to dark amber (ANS) color.
|
|
________ is an enzyme that facilitates the conversion of starch to sugar, which can then be absorbed by the body and used for energy production.
|
Diastase
|
|
In the presence of simple sugars, Iodine potassium-iodide turns a ________.
|
-dark purple/black color
|
|
Diastase is used for?
|
is used in the determination of diastase activity in the enzyme-catalyzed hydrolysis of starch.
|
|
trypsin?
|
•Digests: polypeptides → ammino acids, dipeptides, and tripeptides
•Functional location: pancreatic juice → small intestine •Optimal pH: 8.0 |
|
Lipase
|
• Digests: triglycerides → fatty acids and monoglycerides
• Functional location: pancreatic juice → small intestine • Optimal pH: 8.0 |
|
amylase
|
• Digests: startch → maltose (salivary); starch → maltose, maltriose, and oligosaccharides (pancreas)
• Functional location: mouth or duodenum • Optimal pH: mouth = 6.7; pancreas = 6.7-7 |
|
pepsin
|
• Digests: proteins → smaller polypeptides
• Functional location: gastric glands → stomach • Optimal pH: 1.6-2.4 |