Absorption of lipids

• Absorption of lipids:

  1. Micelles hit epithelial cells and breakdown allowing monoglycerides and fatty acids to diffuse across membranes because they are lipid-soluble
• Absorption of lipids:

  2. Monoglycerides and fatty acids are transported to the Endoplasmic Reticulum where they link to form triglycerides
• Absorption of lipids:

  3. Fatty globules combine with proteins to form chylomicrons (inside golgi apparatus)
• Absorption of lipids:

  4. Chylomicrons travel in a vesicle to the cell membrane and are exocytosed from epithelial cell, and enter a lacteal
• Absorption of lipids:

  5. Lymph in the lacteal transports chylomicrons away from intestine
• Lipid absorption:

  • When the micelles encounter the ileum epithelial cells, due to the non-polar nature of the fatty acids and monoglycerides, they can simply diffuse across the cell surface membrane to enter the cells of the epithelial cells
  • Once in the cell, these will be modified back into triglycerides inside of the endoplasmic reticulum and golgi body
• How micelles help with lipid absorption:

  • They make the fatty acids more soluble in water - (Easier to transport through solution in lumen to get to the epithelial cell)
• How micelles help with lipid absorption:

  • They carry the fatty acids to epithelial cells of the ileum
• How micelles help with lipid absorption:

  • They help to maintain a higher concentration of fatty acids compared to the epithelial cells of the ileum - (Group lots of fatty acids together in the micelles)
  • Fatty acids then released from the micelle and enter the epithelial cell by simple diffusion