There are two forms of active uptake/transport:
1. Active Carrier Transport
2. Endocytosis
1. Active Carrier Transport
Active carrier transport is similar to facilitated diffusion in that it utilizes a protein (carrier). However, energy is also used to move compounds against their concentration gradient. The following figure and video do a nice job of illustrating active carrier transport.
![](https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/2569/2017/10/23202154/100002010000027B0000011D9A6D20B8.png)
Figure 4.321 Sodium-potassium ATPase (aka sodium-potassium pump) an example of active carrier transport1
Web Link |
2. Endocytosis
Endocytosis is the engulfing of particles, or fluids, to be taken up into the cell. If a particle is endocytosed, this process is referred to as phagocytosis. If a fluid is endocytosed, this process is referred to as pinocytosis as shown below.
![](https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/2569/2017/10/23202156/10000201000002A00000015076CF6269.png)
Figure 4.322 Different types of endocytosis2
The following video does a really nice job of showing how endocytosis occurs.
Web Link |
References & Links
1. https://en.wikipedia.org/wiki/File:Scheme_sodium-potassium_pump-en.svg
2. http://commons.wikimedia.org/wiki/File:Endocytosis_types.svg
Videos
Active Transport – http://www.youtube.com/watch?v=STzOiRqzzL4
Endocytosis – http://www.youtube.com/watch?v=4gLtk8Yc1Zc