Updated: 10/8/2020

Glucose Transport

0%
Topic
Review Topic
0
0
N/A
N/A
Questions
4 4
0
0
0%
0%
Evidence
2 2
0
0

Overview
  • Sodium/glucose cotransporter (SGLT)
    • function
      • transport glucose actively across lumen against concentration gradient
        • energy provided by transport of sodium down its concentration gradient
    • location
      • small intestine (SGLT1) 
        • 2:1 Na+:Glu
      • proximal tubule of nephron (SGLT2)
        • 1:1 Na+:Glu
  • Glucose transporters (GLUT)
    • function
      • facilitated diffusion of glucose down concentration gradients  
        • with increasing glucose concentration, rate of transport assumes a hyperbolic curve due to carrier saturation 
      • divided into many subtypes that localize to different tissues
  • GLUT-1
    • function
      • basal glucose uptake
        • high affinity
          • transporters saturated at normal blood glucose levels
          • ensures glucose entry to cells
    • location
      • wide distribution in tissues in the body (brain, erythrocytes, endothelial cells, cornea etc.)
  • GLUT-2
    • function
      • low affinity glucose uptake
        • in the fasting state glucose does not enter cells
        • mediates glucose surplus storage in liver when blood glucose levels rise
        • facilitates insulin release in β-cells
    • location
      • hepatocytes
      • pancreatic β-cells
      • kidney
      • small intestines
  • GLUT-3
    • function 
      • high affinity glucose uptake
        • glucose preferentially accessed by neurons in low-glucose states
    • location
      • brain
      • neurons
  • GLUT-4
    • function
      • insulin-controlled uptake of glucose
      • basal level of glucose intake without insulin
        • presence of insulin ↑ translocation of transporters to the cell membrane
          • ↑↑↑ glucose uptake
          • also stimulated by exercise
    • location
      • adipocytes
      • myocytes
      • cardiomyocytes
 

Please rate topic.

Average 4.8 of 10 Ratings

Questions (4)
Question locked
Sorry, this question is for
PEAK Premium Subscribers only
Upgrade to PEAK
Question locked
Sorry, this question is for
PEAK Premium Subscribers only
Upgrade to PEAK
Question locked
Sorry, this question is for
PEAK Premium Subscribers only
Upgrade to PEAK

(M1.BC.12.7) Certain glucose transporters that are expressed predominantly on skeletal muscle cells and adipocytes are unique compared to those transporters found on other cell types within the body. Without directly affecting glucose transport in other cell types, which of the following would be most likely to selectively increase glucose uptake in skeletal muscle cells and adipocytes? Tested Concept

QID: 100308
1

Increased levels of circulating insulin

76%

(238/313)

2

Decreased levels of circulating insulin

3%

(9/313)

3

Increased plasma glucose concentration

14%

(44/313)

4

Decreased plasma glucose concentration

3%

(10/313)

5

It is physiologically impossible to selectively increase glucose uptake in specific cells

3%

(10/313)

M 1 E

Select Answer to see Preferred Response

Evidence (3)
Topic COMMENTS (17)
Private Note