Lecture 5 - Digestion and Absorption of Carbohydrates Flashcards Preview

Fuel Metabolism - 2016 > Lecture 5 - Digestion and Absorption of Carbohydrates > Flashcards

Flashcards in Lecture 5 - Digestion and Absorption of Carbohydrates Deck (20)
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1
Q

In the oral cavity, a-amylase is an ___________ that randomly cleaves internal a(1-4) glucosidic bonds.

A

endoglucosidase

2
Q

Chyme moves through the duodenum into the small intestine to stimulate the release of _____ and _____.

A

secretin and CCK

3
Q

Where does the pancreatic phase of carbohydrate digestion occur?

A

lumen of the small intestine

4
Q

Where does the disaccharidase phase of carbohydrate digestion occur?

A

mucosal brush border cells

5
Q

Cholecystokinin (CCK) stimulates the release of:

A

pancreatic a-amylase (and other digestive enzymes) that cleaves a-(1,4) glucosidic bonds

6
Q

3 products generated by a-amylase in the small intestine are:

A
  1. maltose
  2. glucose
  3. limit dextrins
7
Q

Which is NOT a product generated by a-amylase in the small intestine?

A. Maltose
B. Glucose
C. Maltase
D. Limit dextrins

A

C - Maltase is a disaccharidase embedded in the glycocalyx

8
Q

___________ is an a-glucosidase that hydrolyzes maltose to 2 molecules of glucose.

A. Lactase
B. Maltase
C. Maltosase
D. Dextrinase
E. Sucrase
A

B

9
Q

_______ is a B-galactosidase that cleaves lactose to galactose and glucose.

A. Lactase
B. Maltase
C. Maltosase
D. Dextrinase
E. Sucrase
A

A

10
Q

What is the function of Mucin secretion by Goblet Cells?

A

provides a protective coating for the disaccharidases

11
Q

______ transports glucose and galactose from the lumen into the intestinal mucosal cell.

A. SGLT1
B. GLUT5
C. GLUT2
D. GLUT4
E. GLUT3
A

A

12
Q

_______ transports fructose from the lumen into the intestinal cell.

A. SGLT1
B. GLUT5
C. GLUT2
D. GLUT4
E. GLUT3
A

B

13
Q

________ transports all 3 hexoses from the intestinal cytosol into the portal circulation.

A. SGLT1
B. GLUT5
C. GLUT2
D. GLUT4
E. GLUT3
A

C

14
Q

Carbohydrates are absorbed from the intestinal lumen in the:

A

upper jejunum

15
Q

Which is NOT located in the brush border membrane?

A. SGLT1
B. GLUT5
C. GLUT2

A

C - GLUT2 is located in the basolateral membrane

16
Q

Which glucose transporter in the GLUT family has the highest affinity and rate of transport for glucose?

A

GLUT3 - supplies energy to the brain even at low blood glucose levels

17
Q

Which glucose transporter is stimulated by insulin?

A

GLUT4 - enriched in fat cells, skeletal muscle, heart muscle

18
Q

Which glucose transporter has a low affinity and high capacity for glucose transport?

A

GLUT2 - enriched in hepatocytes, pancreatic B-cells, kidney, and the basolateral membrane

19
Q

Which glucose transporter is enriched in red blood cells and endothelial cells of the blood brain barrier?

A

GLUT1

20
Q

3 diagnostic tests for lactose intolerance include:

A
  1. Direct Assay for Enzyme
  2. Blood Glucose after Lactose Load
  3. Hydrogen Breath Test after Lactose Load