Absorption of Glucose in the intestine is by:
Absorption of Glucose in the intestine is mediated by the sodium-Glucose cotranspoer proteins (The SGLT proteins). These Co-transpoers are an example of secondary active transpo. Secondary active transpo is a form of active transpo across a biological membrane in which a transpoer protein couples the movement of an ion (typically Na+ or H+) down its electrochemical gradient to the uphill movement of another molecule or ion against or ion against a concentration/electrochemical gradient. Absorption of Glucose in the intestine is mediated by the sodium-Glucose cotranspoer proteins (The SGLT proteins). SGLT activity use the energy from this downhill sodium ion gradient created by the ATPase pump to transpo glucose across the apical membrane, against an uphill glucose gradient. These co-transpoer are an example of secondary active transpo. Two processes involved in the Uptake of Glucose: Facilated duiffusion (a passive process): Mediated by GLUT Transpo Secondary active transpo (an active process): Mediated by SGLT Co-transpoers Major Glucose transpoers: Facilitative bidirectional transpoers (Facilitated Diffusion): GLUT 1 Brain, Kidney, Colon, Placenta, erythrocytes Glucose uptake GLUT 2 Liver, Pancreatic beta cell, small intestine , kidney Rapid uptake or release of glucose GLUT 3 Brain, Kidney, Placenta Glucose uptake GLUT 4 Hea and skeletal muscle, adipose tissue Insulin-stimulated glucose uptake GLUT 5 Small intestine Absorption of fructose Sodium dependent unidirectional transpoer (Secondary Active Transpo) SGLT 1 Small intestine (Also kidney) Active uptake of glucose against a concentration SGLT 2 Kidney Active uptake of glucose against a concentration gradient In the kidneys, 100% of the filtered glucose in the glomerulus has to be reabsorbed along the nephron. 98% of the load is absorbed in the proximal convoluted tubule (PCT) the SGLT2 protein. Remaining two percent is absorbed and the proximal straight tubule (PST) the SGLT 1 protein. Ref: Ganong
Primary Active Transpo
Secondary Active Transpo
Facilitated Diffusion
Simple Diffusion
G.I.T