glucose import across plasma membrane

Definition

Target type: biologicalprocess

The directed movement of glucose from outside of a cell, across the plasma membrane and into the cytosol. [GOC:dos]

Glucose import across the plasma membrane is a crucial process for cells to obtain energy. It involves the movement of glucose from the extracellular space, where it's typically at a higher concentration, into the cell's cytoplasm, where it can be used for metabolic processes. This transport is facilitated by specialized membrane proteins called glucose transporters (GLUTs).

There are various GLUT isoforms, each with specific tissue expression patterns and affinities for glucose. The process of glucose import can be broadly categorized into two main mechanisms:

1. **Facilitated Diffusion (GLUT-mediated):** This is the primary mechanism for glucose uptake in most cells. GLUTs are transmembrane proteins that provide a pathway for glucose to cross the plasma membrane down its concentration gradient. The GLUT protein binds to glucose on the extracellular side of the membrane, undergoes a conformational change, and releases glucose into the cytoplasm. This process does not require ATP (energy) as it relies on the concentration gradient of glucose.

2. **Active Transport (Sodium-Glucose Cotransporter - SGLT):** This mechanism is found primarily in the small intestine and proximal tubules of the kidneys. SGLTs utilize the energy of the sodium gradient to move glucose against its concentration gradient. This means that glucose can be transported into cells even when the intracellular glucose concentration is higher than the extracellular concentration. SGLTs bind both sodium and glucose simultaneously, and the movement of sodium down its electrochemical gradient provides the energy to drive glucose transport.

The specific mechanism of glucose transport varies depending on the cell type and the physiological conditions. However, the overall process involves the interaction of glucose with specific membrane proteins that facilitate its passage across the plasma membrane. This process is essential for cellular function and energy production.'
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Proteins (4)

Compounds (38)