Lecture 11 Cellular Secretions Flashcards Preview

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Flashcards in Lecture 11 Cellular Secretions Deck (17):
1

What is milk secreted by?

Mammary epithelial cells that line the alveoli in mammary glands

2

Name a few molecules secreted by mammals

proteins, peptides, steroids and ions

3

How are proteins synthesized?

Synthesized by ribosomes attatched to rough ER, enter lumen, sorted and transported

4

Extracellular Matrix

A collection of molecules secreted by cells that provide structural support and biochemical support to surrounding cells.

5

Where are digestive enzymes found?

Stomach, small intestine or acinar cells of the exocrine pancreas

6

Explain how zymogens need to be packaged

They must be compartmentalized in secretory vesicles in its inactive form (zymogen)

7

Why do zymogens need to be packaged a certain way?

To prevent the secretory cells from self destruction

8

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

9

What do the vesicles contain? (acinar)

Granules of pancreatic enzyme precursors like chymo-trypsinogen

10

Exocytosis

A process in which the contents of secretory vesicles are discharged into the lumen

11

Endocytosis

A process in which a cell transports contents into the cell by engulfing it

12

What is chymo-trypsinogen?

An inactive form of digestive enzyme that digests things in chyme

13

Trypsin

Found in the digestive system, it hydrolyses proteins

14

Where and how is trypsin formed?

In the small intestine. Its proenzyme (trypsinogen) forms trypsin when it cleaves peptide chains.

15

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

16

Bile salts

Secreted via bile duct to emulsify fats to aid digestion

17

How is acidic chyme neutralised?

Bicarbonate ions mixed with digestive enzymes secreted by the exocrine pancreas