Nutrition Chapter on Lipid Digestion

The breakdown of dietary fat (triglycerides, TG) into smaller components, like fatty acids, by enzymes called lipases in the small intestine.

Bile salts, produced by the liver, help to break down large fat globules into smaller droplets, increasing their surface area for enzyme action.

Micelles are tiny, spherical structures formed by bile salts and digested fat molecules. They allow the absorption of fat into the intestinal cells.

The process where digested fat components (mainly fatty acids and monoglycerides) are transported from the intestinal lumen into the bloodstream.

Chylomicrons are tiny particles that transport dietary fats from the small intestine to other tissues in the body.

A type of lipid that makes up more than 95% of dietary fat. It's the main form of energy storage in the body, providing 9.24 kcal/g.

A type of lipid that forms the structural components of cell membranes. They have a hydrophilic head and hydrophobic tails, allowing them to form bilayer membranes.

A type of lipid that functions as a transport form of cholesterol in the blood and cells, helping to regulate cholesterol levels.

A type of lipase enzyme secreted by the tongue that starts the digestion of triglycerides in the mouth, especially important for newborns.

A type of lipase enzyme secreted by the stomach that continues triglyceride digestion, especially efficient for short and medium chain fatty acids.

The process of digesting dietary fats, involving the breaking down of triglycerides into smaller units.

The key enzyme responsible for most of the digestion of triglycerides in the small intestine, activated by bile.

Bile salts are synthesized in the liver, stored in the gallbladder, and are derived from cholesterol. They consist of a sterol ring, a side chain, and either glycine or taurine. Bile salts are Na & K salts of Glycocholic & Taurocholic acid and play a crucial role in fat digestion.

Bile salts act as effective emulsifying agents, breaking down large fat globules into smaller droplets, increasing their surface area for enzyme action.

The small intestine is the primary location for fat digestion. Here, pancreatic lipase, aided by bile salts, effectively breaks down fats.

Increased gastric acidity or protein-rich content in the duodenum stimulates the secretion of pancreatic juice. This juice contains enzymes crucial for digesting fats.

Secretin, a hormone released in the gut, increases the secretion of electrolytes and bicarbonate-rich fluid in pancreatic juice. This fluid neutralizes the acidic chyme from the stomach.

Cholecystokinin (CCK), another gut hormone, stimulates the secretion of pancreatic enzymes and the contraction of the gallbladder, releasing bile into the small intestine.

Pancreatic lipase is the primary enzyme responsible for breaking down triglycerides (fats) into fatty acids and glycerol.

Phospholipases, also present in pancreatic juice, break down phospholipids into fatty acids, glycerol, and phosphate.

The process where chylomicrons, carrying absorbed triglycerides, enter cells, allowing the triglycerides to be broken down and used for energy or stored.

Lipoprotein lipase is an enzyme attached to blood vessel walls, specifically in capillary endothelial cells. It breaks down triglycerides into fatty acids and glycerol, allowing them to be absorbed by tissues.

The process where chylomicrons, composed of triglycerides and other lipids, are assembled in intestinal cells after fat absorption. They then travel through the lymphatic system and enter the blood.

Several factors can disrupt lipid absorption and cause a condition called Steatorrhea, characterized by excessive fat in stool. Examples include pancreatic insufficiency, cystic fibrosis, and intestinal diseases.

After entering the cell, the chylomicron breaks down, releasing its triglycerides (fatty acids) for use in the cells. This process provides valuable energy and precursors for various cellular processes.

Proteins that associate with lipoproteins, helping them interact with cells and regulate their metabolism.

A type of chylomicron that has just been assembled by intestinal cells and is not yet fully mature.

A mature chylomicron that has acquired additional apoproteins, primarily from HDL in the lymph and blood, becoming more stable and efficient for lipid transport.

The process of exocytosis by which nascent chylomicrons are released from intestinal epithelial cells into the lymphatic system and then blood.

The increase in blood lipid levels, particularly chylomicrons, after the consumption of a fatty meal.

High density lipoprotein, a lipoprotein with the highest protein concentration and comparatively low triacylglycerol content, crucial for reverse cholesterol transport and supplying apoproteins to nascent chylomicrons.

The process by which chylomicrons are broken down by lipoprotein lipase in various tissues (muscle, adipose) to release free fatty acids for energy use.