3.5 Active Transport, Endocytosis, and Exocytosis
8
KEY CONCEPT Cells use ENERGY to transport materials that cannot diffuse across a membrane . 3.5 Active Transport, Endocytosis, and 3.5 Active Transport, Endocytosis, and Exocytosis Exocytosis Take a look at your Power Notes. Complete your diagram using this example.
-
Upload
pascale-blanchard -
Category
Documents
-
view
164 -
download
3
description
3.5 Active Transport, Endocytosis, and Exocytosis. KEY CONCEPT Cells use ENERGY to transport materials that cannot diffuse across a membrane. Take a look at your Power Notes. Complete your diagram using this example. Active Transport. - PowerPoint PPT Presentation
Transcript of 3.5 Active Transport, Endocytosis, and Exocytosis
KEY CONCEPT Cells use ENERGY to transport materials that cannot diffuse across a membrane.
3.5 Active Transport, Endocytosis, and Exocytosis3.5 Active Transport, Endocytosis, and Exocytosis
Take a look at your Power Notes.
Complete your diagram using this example.
Active transport requires energy input from a cell and enables a cell to move a substance against its concentration gradient, from a region of lower concentration to a region of higher concentration.
• Active transport is powered by chemical energy (ATP).
Active TransportActive Transport
• Cells use active transport to maintain homeostasis.
• Active transport occurs through transport protein pumps.
MAIN IDEA: A cell can import and export large materials or large amounts of material in vesicles during the processes of endocytosis and exocytosis. Energy is required!
EndocytosisEndocytosis
Endocytosis is the process of taking material into the cell such as liquids or fairly large molecules by engulfing (surrounding) them in a membrane.
Now, let’s draw the steps and include good details in our explanations!
Steps of EndocytosisSteps of Endocytosis
During Endocytosis, the cell membrane folds inward and fuses together. This surrounds the substance in a pocket.
The pocket pinches off inside of the cell, forming a vesicle.
The vesicle fuses with a lysosome or similar vesicle. Then, enzymes break down the membrane AND the contents inside!
PhagocytosisPhagocytosis
Phagocytosis is a type of endocytosis where the cell membrane engulfs large particles.•Phagocytosis actually means “cell eating.”•It plays a key role in our immune systems.
How? Some white blood cells in the human body are called
macrophages. Their purpose is to help fight infection.
They seek out foreign materials in the body, such as bacteria and engulf and destroy them!
• Exocytosis is the opposite of endocytosis. It is the release or expelling of substances out of a cell by the fusion of a vesicle WITH the membrane.
ExocytosisExocytosis
Once again, let’s draw the steps and include good details in our explanations!
Steps of ExocytosisSteps of Exocytosis
The cell forms a vesicle around material that needs to be expelled from the cell.
The vesicle is transported to the cell membrane.
The vesicle membrane fuses with the cell membrane and releases the contents from the cell.
What?????? HOMEWORK???? What?????? HOMEWORK????
This homework will be turned into the teacher This homework will be turned into the teacher tomorrow for a homework grade at the tomorrow for a homework grade at the beginning of class! beginning of class!
You will have a quiz over 3.5 tomorrow and a You will have a quiz over 3.5 tomorrow and a test over 3.3-3.5 on Monday! test over 3.3-3.5 on Monday!
This PowerPoint will be on the Biology This PowerPoint will be on the Biology wikispace tonight so that you can finish your wikispace tonight so that you can finish your notes and worksheets!notes and worksheets!
