Glucose transporter type 1 (GLUT1) is a protein that facilitates the transport of glucose across cell membranes. It is primarily found in the brain, red blood cells, and the blood-brain barrier, where it plays a crucial role in providing energy to cells by allowing glucose to enter. GLUT1 operates through a process called facilitated diffusion, which means it helps glucose move from areas of higher concentration to lower concentration without using energy. This transporter is essential for maintaining normal glucose levels in the body and is involved in various metabolic processes.