Fructose uptake in small intestine is ?
**Core Concept**
Fructose uptake in the small intestine is an essential process for carbohydrate digestion and absorption. It involves specific transport proteins and mechanisms to facilitate the movement of fructose across the intestinal epithelial cells. The process is crucial for the normal utilization of dietary fructose.
**Why the Correct Answer is Right**
Fructose uptake in the small intestine primarily occurs through facilitated diffusion via the sodium-dependent glucose cotransporter 5 (SGLT5). However, the main mechanism is through the fructose transporter, GLUT5, which is a member of the facilitated diffusion glucose transporter family. GLUT5 is highly expressed in enterocytes and is responsible for the specific uptake of fructose. The absorbed fructose is then transported to the liver via the portal vein.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect as it doesn't specify the correct transport mechanism or protein involved in fructose uptake.
**Option B:** This option is incorrect as it refers to a different type of transport mechanism and is not relevant to fructose uptake in the small intestine.
**Option C:** This option is incorrect as it refers to a different type of transport protein and is not specific to fructose uptake.
**Clinical Pearl / High-Yield Fact**
It's essential to remember that the small intestine is the primary site for fructose absorption, and impaired fructose uptake can lead to malabsorption and associated symptoms such as bloating, gas, and abdominal pain.
**Correct Answer: C. GLUT5**