Transport of Extra-Large Molecules (Bulk Packaging)

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• Some molecules are WAY TOO LARGE for the previously mentioned transport methods.

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• For example, some unicellular organisms will ingest ENTIRE CELLS!!! WOW!!!

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• When this is the case, endocytosis and exocytosis are the preferred method of (bulk)transport. This comes with a price the cell must pay.

ENERGY USED!!!

Movement of Extra-Large Molecules (Bulk Packaging)

• BULK FLOW
• Large molecules move across cell membrane in membrane-bound sacs.
• ENDOCYTOSIS- into the cell
• EXOCYTOSIS- out of the cell

Endocytosis- is a process by which a cell surrounds and takes in material from its environment. The basic steps are as follows:

1. Engulf

2. Enclose

3. Vacuole formation

The reverse of this process is known as exocytosis; removes wastes.

Movement of Extra-Large Molecules (Bulk Packaging)

Two Types of Endocytosis

• ENDOCYTOSIS
• Phagocytosis- cell eating; solid particles move into the cell.�
• Pinocytosis- cell drinking; liquids move into the cell.

Summary of Cellular Transport

Active or Passive

1. Phagocytosis
2. Osmosis
3. Diffusion
4. Endocytosis
5. Exocytosis
6. Facilitated Diffusion
7. Pinocytosis

• Active or Passive
• Active or Passive
• Active or Passive
• Active or Passive
• Active or Passive
• Active or Passive
• Active or Passive

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