1 / 5

3.5 Active Transport, Endocytosis, and Exocytosis

3.5 Active Transport, Endocytosis, and Exocytosis. KEY CONCEPT Cells use energy (ATP) to transport materials that cannot diffuse across a membrane. 3.5 Active Transport, Endocytosis, and Exocytosis.

Download Presentation

3.5 Active Transport, Endocytosis, and Exocytosis

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. 3.5 Active Transport, Endocytosis, and Exocytosis • KEY CONCEPT Cells use energy (ATP) to transport materials that cannot diffuse across a membrane.

  2. 3.5 Active Transport, Endocytosis, and Exocytosis • Active transport requires energy input from a cell and enables a cell to move a substance against its concentration gradient. • Passive transport requires no energy from the cell. • Active transport is powered by chemical energy (ATP). • Active transport occurs through transport protein pumps. • Cells use active transport to maintain homeostasis. • Synthesize: In what ways are active transport proteins similar to enzymes?

  3. 3.5 Active Transport, Endocytosis, and Exocytosis • A cell can import and export large materials or large amounts of material in vesicles during the processes of endocytosis and exocytosis. • Cells use energy (ATP) to transport material in vesicles. • Endocytosis is the process of taking material into the cell. • Phagocytosis is a type of endocytosis in which the cell membrane engulfs large particles. Sometimes is called “cell eating”. • During endocytosis, the cell membrane folds inward and fuses together surrounding the substance in a pocket . • The vesicle fuses with a lysosome, or a similar vesicle, where enzymes break down the membrane and its contents. • The pocket pinches off inside the cell, forming a vesicle.

  4. 3.5 Active Transport, Endocytosis, and Exocytosis • A cell can import and export large materials or large amounts of material in vesicles during the processes of endocytosis and exocytosis. • Cells use energy (ATP) to transport material in vesicles. • Exocytosis is the process of expelling material from the cell. • The cell forms a vesicle around material that needs to be removed or secreted. • The vesicle membrane fuses with the cell membrane and releases the contents. • The vesicle is transported to the cell membrane.

  5. Examples of Endocytosis and Exocytosis • Endocytosis – plays a role in the human immune system. • White blood cells called macrophages help your body fight infection by engulfing and destroying materials that do not belong in your body like bacteria cells. • Exocytosis/Endocytosis – plays a role in the human nervous system. • Vesicles within nerve cells carry and release chemicals to other cells to transmit nerve impulses that for example, will cause your muscles to contract. • Hypothesize: What might happen if vesicles in your neurons were suddenly unable to fuse with the cell membrane?

More Related