Intended Learning Outcomes By the end of this
Intended Learning Outcomes By the end of this lecture You will be able to: • Differentiate between the ways of absorption of carbohydrates. • Differentiate between simple diffusion, facilitated and active transport.
BY Dr. Marwa Ali Lecturer Of Biochemistry And Molecular Biology
Absorption Of Monosaccharides Most of the carbohydrates are absorbed from the duodenum and upper jejunum by an insulin independent mechanism.
Monosaccharides Transport into the cells 1. Active transport: Both Energy & carrier are needed Galactose and glucose by SGLT-1 2. Facilitated diffusion (no Energy is needed But carrier is needed) Fructose by “GLUT 5”
Absorption Of Monosaccharides 1. Active Absorption (Energy consuming) That involves a special protein transporter with co- Na transport sodium-dependent glucose cotransporter 1 (SGLT-1). (Glucose & Galactose)
Na++ Na-K ATPase (Portal circulation) B. V K+ 2 Na++ Glucose& Galactose Duodenum & upper jejunum
2. Facilitated diffusion (no Energy is needed But carrier is needed) Fructose by “GLUT 5”
Glucose Transporters • GLUT 1 : Brain and RBCs. • GLUT 2 : Hepatocytes , β-cells of pancreas, intestine. • GLUT 3 : Brain • GLUT 4 : Adipose tissue, Heart and Muscles (insulin dependent) • GLUT 5 : Intestinal epithelium 1 2 β cells Of Pancrease 4
Dr. Marwa Ali
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