21. Secretory Vesicles

Question 1

Secretory vesicles? Excretion?

Answer 1

Secretory vesicles contain materials that are to be excreted from the cell.

Cells have many reasons to excrete materials:

1) Dispose of wastes
2) Another reason is tied to the function of the cell

Within a larger organism - cells are specialized to produce certain chemicals. These chemicals are stored in secretory vesicles –> released when req

Question 2

Location of Synaptic vesicles? How does it occur?

Answer 2

•Synaptic vesicles are located at presynaptic terminals in neurons and store neurotransmitters.

• When a signal comes down an axon
• The synaptic vesicles fuse with the cell membrane releasing the neurotransmitter so that receptor molecules on the next nerve cell can detect it

Question 3

Secretory vesicles in animals?

Answer 3

• In animals endocrine tissues –> release hormones into the bloodstream.
• These hormones are stored within secretory vesicles - Example: endocrine tissue in the islets of Langerhans (pancreas)

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Question 4

Secretory Vesicles and Enzymes?

Answer 4

• Secretory vesicles hold the enzymes that are used to make the cell walls (plants, protists, fungi, bacteria, and Archaea cells) and the extracellular matrix of animal cells.

Question 5

Membrane vesicles?

Answer 5

Bacteria, Archaea, Fungi, and parasites release membrane vesicles (MVs) containing
- specialized toxic compounds
- biochemical signal molecules
which are transported to target cells to initiate processes - include invasion of host cells /killing of competing microbes in the same niche.

Question 6

What are zygomens?

Answer 6

Secretory vesicles containing digestive enzymes are known as zymogens