Endocytosis

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Transcript Endocytosis

Active Transport
• Defined: Molecules move from a LOW to a HIGH
concentration
• ATP energy needed to fight diffusion
– ATP = Adenosine Triphosphate
• ATP activates pumps (see animation)
Active Transport Video
Contractile vacuole of a Paramecium
As water enters this cell by diffusion, it is
immediately pumped out to prevent bursting
Endocytosis
• Endocytosis: Process in which the plasma membrane
takes in substances (2 types)
– 1) Phagocytosis: when a cell engulfs a solid particle
– 2) Pinocytosis: when a cell engulfs a liquid particle
• Unfortunately, viruses can also enter our cells this way
Endocytosis & the lysosome
The bacteria is engulfed by
phagocytosis
The bacteria is placed
inside a lysosome are
destroyed
Exocytosis
• Defined: Process when substances are expelled from
the cell
• Proteins, nutrients, and waste exit by exocytosis
• Vesicle carry & release objects through the plasma
membrane
Review
1) How are active and passive transport different?
2) Which molecule powers active transport?
3) How are endo- and exocytosis similar?
Different?
4) Which cell part controls active transport?