Glucose transport
Glucose enters cells by
- facilitated diffusion; OR
- secondary active transport with Na+ (in intestine and kidney)
Glucose transporter
- GLUT 1-7
- Involved in facilitated diffusion.
- Amino and carboxyl terminals inside the cells
- Crosses cell membrane 12 times
GLUT 2
- Located in B cells, liver, epithelial cells of small intestine, kidneys
GLUT 4
- Stimulated by insulin
- Located in muscles and adipose tissues.
- A small population of GLUT4 is released during exercise, independent of insulin.
Sodium-glucose co-transporter
- SGLT 1-2
- Involved in secondary active transport of glucose with sodium
- No homology with GLUTs
- Crosses cell membrane 12 times also.
SGLT 1
Located in small intestine and renal tubules
SGLT 2
Located in renal tubules
