Lipid Digestion and Absorption L3
28 Questions
0 Views
3.5 Stars

Lipid Digestion and Absorption L3

Explore the biochemical aspects of lipid digestion, including organs involved, enzymes required, and end products. Study the synthesis, secretion, and fate of chylomicron, as well as the clinical manifestations of diseases related to lipid digestion and absorption.

Created by
@AlluringDalmatianJasper

Questions and Answers

Which organ is primarily responsible for the majority of lipid digestion?

Small intestine

What is the main component of dietary lipids intake?

Triacylglycerol

Which enzyme is involved in lipid degradation by the pancreatic enzymes?

Pancreatic lipase

What is the fate of absorbed lipid molecules in the body?

<p>Direct utilization by the tissues</p> Signup and view all the answers

What is the approximate daily intake of dietary lipids?

<p>78-81 g/day</p> Signup and view all the answers

What is the remainder of dietary lipids intake, aside from Triacylglycerol?

<p>Phospholipids and Glycolipids</p> Signup and view all the answers

What is a clinical manifestation of diseases involving defective lipid digestion and/or absorption?

<p>Indigestion and malabsorption syndrome</p> Signup and view all the answers

What control pancreatic insufficiency?

<p>Enzyme replacement therapy</p> Signup and view all the answers

Which enzyme is responsible for breaking down triacylglycerides into fatty acids and glycerol?

<p>Pancreatic lipase</p> Signup and view all the answers

What is the main location for the primary contributors to lipid digestion?

<p>Small intestine</p> Signup and view all the answers

What is the role of bile salts in the digestion process?

<p>Emulsifying dietary lipids</p> Signup and view all the answers

Which hormone stimulates the release of bile and pancreatic enzymes?

<p>Cholecystokinin (CCK)</p> Signup and view all the answers

What causes pancreatic insufficiency commonly observed in cystic fibrosis?

<p>Thickening of pancreatic secretions</p> Signup and view all the answers

Which enzyme acts on phospholipids to produce lysophospholipids and free fatty acids?

<p>Phospholipase A2</p> Signup and view all the answers

What is the role of co-lipase in lipid digestion?

<p>Aiding in the activity of pancreatic lipase</p> Signup and view all the answers

Which enzyme hydrolyzes cholesterol esters into free cholesterol and fatty acids?

<p>Cholesterol esterase</p> Signup and view all the answers

What do acid lipases help digest in neonates and patients with pancreatic insufficiency?

<p>Milk fat due to their inability to produce or absorb sufficient pancreatic secretions.</p> Signup and view all the answers

What are the two hormones that control the lipid digestion process?

<p>Cholecystokinin (CCK) and secretin.</p> Signup and view all the answers

Where does emulsification of dietary fats primarily occur?

<p>Duodenum</p> Signup and view all the answers

Chylomicrons are synthesized in which organ?

<p>Liver</p> Signup and view all the answers

Where is the primary site for the absorption of the end products of lipid digestion?

<p>Small intestine</p> Signup and view all the answers

Which enzyme is responsible for the hydrolysis of triglycerides?

<p>Pancreatic Lipase</p> Signup and view all the answers

In lipid digestion, what is the primary function of phospholipase A2?

<p>Breaking down phospholipids</p> Signup and view all the answers

Which organ secretes cholesterol esterase?

<p>Pancreas</p> Signup and view all the answers

What is the role of cholecystokinin (CCK) in the control of lipid digestion?

<p>Acting on the gallbladder to release bile and on the pancreas to release enzymes</p> Signup and view all the answers

What happens to chylomicrons after their synthesis?

<p>They are packaged as lipid droplets surrounded by a thin layer of apolipoprotein B-48 (apo B-48) and phospholipids.</p> Signup and view all the answers

What causes serum to become milky after a fatty meal?

<p>Secretion of chylomicrons into systemic circulation.</p> Signup and view all the answers

What is the main function of mixed micelles in lipid absorption?

<p>Direct absorption by brush border membrane of enterocytes.</p> Signup and view all the answers

Study Notes

  • Gastric lipase is a digestive enzyme secreted in the mouth, but it starts working in the stomach due to the requirement of an acidic medium.
  • Small intestine is where the main lipid digestion takes place, with the enzymes produced in the pancreas being the primary contributors.
  • The key enzymes involved in lipid digestion in the small intestine are: Pancreatic Lipase, Co-lipase, Cholesterol esterase, Phospholipase A2, and Lysophospholipase.
  • Pancreatic lipase is responsible for breaking down triacylglycerides into fatty acids and glycerol, with co-lipase aiding in its activity. Cholesterol esterase hydrolyzes cholesterol esters into free cholesterol and fatty acids. Phospholipase A2 acts on phospholipids to produce lysophospholipids and free fatty acids, while lysophospholipase converts lysophospholipids into glycerophospholipids and fatty acids.
  • Lipases in the stomach (gastric lipase and lingual lipase) hydrolyze the triacylglycerides with short to medium chain fatty acids, enabling their digestion and absorption.
  • Neonates and patients with pancreatic insufficiency rely on acid lipases for milk fat digestion due to their inability to produce or absorb sufficient pancreatic secretions.
  • Bile salts play a crucial role in the digestion process by emulsifying dietary lipids, increasing their surface area, and making them available for enzyme digestion.
  • Pancreatic lipase and co-lipase are essential for the degradation of triacylglycerides, while cholesterol esterase is responsible for cholesterol ester degradation. Phospholipids are digested by phospholipase A2 and lysophospholipase.
  • Pancreatic insufficiency, commonly observed in cystic fibrosis, is caused by defective CFTR (cystic fibrosis transmembrane conductance regulator) and results in decreased secretion of chloride, increased reabsorption of sodium and water, and the thickening of pancreatic secretions, which eventually blocks the pancreatic duct, preventing the enzymes from reaching the intestine and causing malnutrition.
  • Cholecystokinin (CCK) and secretin are two hormones that control the lipid digestion process by stimulating the release of bile and pancreatic enzymes, decreasing gastric motility, and neutralizing the pH of the small intestinal contents.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Quiz Team

More Quizzes Like This

Vitamin K in Biochemistry
28 questions

Vitamin K in Biochemistry

AlluringDalmatianJasper avatar
AlluringDalmatianJasper
Veterinary Medicine: Phosphorus and Nutrient Absorption
70 questions
Use Quizgecko on...
Browser
Browser