Active Transport: Protein Pumps and Endocytosis
description
Transcript of Active Transport: Protein Pumps and Endocytosis
![Page 1: Active Transport: Protein Pumps and Endocytosis](https://reader036.fdocuments.in/reader036/viewer/2022081504/5681487d550346895db58672/html5/thumbnails/1.jpg)
1
Active Transport: Protein Pumps and Endocytosis
Section 3.5
![Page 2: Active Transport: Protein Pumps and Endocytosis](https://reader036.fdocuments.in/reader036/viewer/2022081504/5681487d550346895db58672/html5/thumbnails/2.jpg)
2
Objectives
• SWBAT describe active transport.• SWBAT distinguish among endocytosis,
exocytosis, and phagocytosis.
• Main Ideas– Proteins can transport materials against a
concentration gradient.– Endocytosis and exocytosis transport materials
across the cell membrane in vesicles.
![Page 3: Active Transport: Protein Pumps and Endocytosis](https://reader036.fdocuments.in/reader036/viewer/2022081504/5681487d550346895db58672/html5/thumbnails/3.jpg)
3
Vocabulary Section 3.5
• Endocytosis (endocitosis)• Exocytosis (exocitosis)• Phagocytosis (fagocitosis)• Active transport (transporte activo)• ATP (adenosine triphosphate)
![Page 4: Active Transport: Protein Pumps and Endocytosis](https://reader036.fdocuments.in/reader036/viewer/2022081504/5681487d550346895db58672/html5/thumbnails/4.jpg)
4
Starter
• Small lipid molecules are in high concentration outside a cell. They slowly cross the membrane into the cell. What term describes this action? Does it require energy?
• Diffusion and no.
![Page 5: Active Transport: Protein Pumps and Endocytosis](https://reader036.fdocuments.in/reader036/viewer/2022081504/5681487d550346895db58672/html5/thumbnails/5.jpg)
Two Types of Transport• There are two ways of transporting materials
across a cell membrane. They are:– Passive Transport – we have already looked at this.– Active Transport – actively drives molecules
across the cell membrane from a region of lower concentration to a region of higher concentration. Requires energy input.
5
![Page 6: Active Transport: Protein Pumps and Endocytosis](https://reader036.fdocuments.in/reader036/viewer/2022081504/5681487d550346895db58672/html5/thumbnails/6.jpg)
6
Active Transport
![Page 7: Active Transport: Protein Pumps and Endocytosis](https://reader036.fdocuments.in/reader036/viewer/2022081504/5681487d550346895db58672/html5/thumbnails/7.jpg)
7
Active Transport
Active transport drives molecules across a membrane from region of lower concentration to a region of higher concentration (remember our bicycle example).
There are transport proteins that allow diffusion but there are others, often called pumps, that move materials against the concentration gradient.
![Page 8: Active Transport: Protein Pumps and Endocytosis](https://reader036.fdocuments.in/reader036/viewer/2022081504/5681487d550346895db58672/html5/thumbnails/8.jpg)
8
Active Transport
Active transport requires energy input from a cell and enables a cell to move a substance against its concentration gradient.
Cells use active transport to get needed molecules regardless of the concentration gradient to maintain homeostasis.
![Page 9: Active Transport: Protein Pumps and Endocytosis](https://reader036.fdocuments.in/reader036/viewer/2022081504/5681487d550346895db58672/html5/thumbnails/9.jpg)
9
Question
• Are the protein pumps, like the Na/K pump in neurons, active or passive transport?
• Explain how a protein pump works?• What kind of energy does it use?
![Page 10: Active Transport: Protein Pumps and Endocytosis](https://reader036.fdocuments.in/reader036/viewer/2022081504/5681487d550346895db58672/html5/thumbnails/10.jpg)
10
ATP (Adenosine Triphosphate)
ATP is chemical energy made in a cell’s mitochondria.
Besides in neurons, like we have already seen, ATP is needed to drive many other processes – including the making of ATP.
ATP is used in the mitochondrial proton pump, moving hydrogen ions (H+) across the inner mitochondrial membrane. This proton pump is essential for the creation of ATP.
![Page 11: Active Transport: Protein Pumps and Endocytosis](https://reader036.fdocuments.in/reader036/viewer/2022081504/5681487d550346895db58672/html5/thumbnails/11.jpg)
11
ATP
Like with sodium and potassium in the neuron, the hydrogen ions are “pumped,” using ATP, across the mitochondrial inner membrane (against the H+ gradient).
They then diffuse across the membrane through a protein channel (an enzyme called ATP Synthase).
The enzyme uses the movement of the H+ to create ATP from a precursor called ADP.
![Page 12: Active Transport: Protein Pumps and Endocytosis](https://reader036.fdocuments.in/reader036/viewer/2022081504/5681487d550346895db58672/html5/thumbnails/12.jpg)
12
ATP Video
• http://highered.mcgraw-hill.com/sites/9834092339/student_view0/chapter38/proton_pump.html
![Page 13: Active Transport: Protein Pumps and Endocytosis](https://reader036.fdocuments.in/reader036/viewer/2022081504/5681487d550346895db58672/html5/thumbnails/13.jpg)
13
Transport Proteins• All transport proteins/enzymes (which are
proteins) span a membrane.• Most change shape when they bind to a target
molecule or molecules. • As we have seen, some transport proteins bind to
only one type of molecule. • Others bind to 2 different types.
– Those that bind to two types can move both types of molecules either one way or opposite directions (like the sodium/potassium pump we saw in the neuron.
![Page 14: Active Transport: Protein Pumps and Endocytosis](https://reader036.fdocuments.in/reader036/viewer/2022081504/5681487d550346895db58672/html5/thumbnails/14.jpg)
14
Question
• How do transport proteins that are pumps differ from those that are channels?
![Page 15: Active Transport: Protein Pumps and Endocytosis](https://reader036.fdocuments.in/reader036/viewer/2022081504/5681487d550346895db58672/html5/thumbnails/15.jpg)
15
Endocytosis
• Endocytosis – the process of taking liquids or fairly large molecules into a cell by engulfing them in a membrane. – The cell membrane makes a pocket around the
substance.
![Page 16: Active Transport: Protein Pumps and Endocytosis](https://reader036.fdocuments.in/reader036/viewer/2022081504/5681487d550346895db58672/html5/thumbnails/16.jpg)
16
Endocytosis
![Page 17: Active Transport: Protein Pumps and Endocytosis](https://reader036.fdocuments.in/reader036/viewer/2022081504/5681487d550346895db58672/html5/thumbnails/17.jpg)
17
Endocytosis
• The pocket breaks off inside the cell and forms a vesicle.– The vesicle then fuses with a lysosome.
Lysosomal enzymes break down the vesicle membrane and the vesicle’s contents are release into the cell.
![Page 18: Active Transport: Protein Pumps and Endocytosis](https://reader036.fdocuments.in/reader036/viewer/2022081504/5681487d550346895db58672/html5/thumbnails/18.jpg)
18
Phagocytosis
• Phagocytosis – the word literally means “cell eating.”
• It is a special type of endocytosis which plays a major role in your immune system.
• White blood cells find foreign materials, such as bacteria, engulf them and destroy them. – They are your body’s enforcers.