Practice question

Sodium glucose cotransporters SGLT1 SLC5A1 and SGLT2 SLC5A2 are secondary active members using sodium gradient but differ in location, affinity and role. SGLT1 expressed predominantly in apical brush border of small intestine enterocytes and early kidney proximal tubule S3 is high-affinity low-capacity with 2 Na+ to 1 glucose stoichiometry handling dietary glucose and galactose absorption and some glucose reabsorption. SGLT2 localized exclusively in S1 and S2 segments of proximal tubule is low-affinity high-capacity with 1 Na+ to 1 glucose stoichiometry accounting for roughly 90 percent renal glucose reabsorption of filtered load near 180 g per day. Dysfunction produces renal glycosuria. SGLT2 inhibitors gliflozins empagliflozin and dapagliflozin block renal reabsorption promoting glycosuria, used for type 2 diabetes with cardiovascular benefits. Describing SGLT2 as intestinal transporter conflates families; SGLT1 dominates gut while SGLT2 dominates kidney. Neither functions as proton pump or cystic fibrosis related channel. Such detailed mechanistic insight is frequently examined in competitive tests including NEET, CUET, CSIR-NET and GATE where transporter classification, energetics and disease linkage are integrated into problem-solving questions.