Flashcards in Lecture 11 Cellular Secretions Deck (17):
What is milk secreted by?
Mammary epithelial cells that line the alveoli in mammary glands
Name a few molecules secreted by mammals
proteins, peptides, steroids and ions
How are proteins synthesized?
Synthesized by ribosomes attatched to rough ER, enter lumen, sorted and transported
A collection of molecules secreted by cells that provide structural support and biochemical support to surrounding cells.
Where are digestive enzymes found?
Stomach, small intestine or acinar cells of the exocrine pancreas
Explain how zymogens need to be packaged
They must be compartmentalized in secretory vesicles in its inactive form (zymogen)
Why do zymogens need to be packaged a certain way?
To prevent the secretory cells from self destruction
Describe the process of acinar cells
Synthesized into the lumen, transported to the Golgi, packaged into secretory vesicles and stored in the cell ready for release
What do the vesicles contain? (acinar)
Granules of pancreatic enzyme precursors like chymo-trypsinogen
A process in which the contents of secretory vesicles are discharged into the lumen
A process in which a cell transports contents into the cell by engulfing it
What is chymo-trypsinogen?
An inactive form of digestive enzyme that digests things in chyme
Found in the digestive system, it hydrolyses proteins
Where and how is trypsin formed?
In the small intestine. Its proenzyme (trypsinogen) forms trypsin when it cleaves peptide chains.
What happens to food once in the stomach
Pepsin released from chief cells in the stomach mucosa digests proteins in HCL by parietal cells in gastric glands
Secreted via bile duct to emulsify fats to aid digestion