The Naked Scientists

The Naked Scientists Forum

Author Topic: Where do dead cells go to?  (Read 5862 times)

Offline The Scientist

  • Sr. Member
  • ****
  • Posts: 286
  • Its great to be me!
    • View Profile
Where do dead cells go to?
« on: 30/06/2010 16:30:33 »
Where do dead cells go to? Which part of the body does it get destroyed.

P.S. Cells in general


 

Offline tangoblue

  • Sr. Member
  • ****
  • Posts: 301
  • RANDOMNESS RULES!!!
    • View Profile
Where do dead cells go to?
« Reply #1 on: 27/10/2010 00:11:22 »
A type of white blood cell called a macropbage is redponsible for dealing with our dead cells.  macrophages are in our organs and they also travel through our bloodstream.  when a macrophage comes across a dead cell it 'eats' it. (phagocytosis)
 

SteveFish

  • Guest
Where do dead cells go to?
« Reply #2 on: 27/10/2010 02:26:31 »
Cells are disposed of in a manner that completely recycles all the components. As Tangoblue said macrophages, but also some other cell types (e.g. neutrophils), are important in recycling just about everything that needs to be removed from the interior of the body. They utilize the "cellular stomach" (lysosomes and proteosomes) to digest material down to basic components such as amino acids and sugars. The epithelial cells lining the GI tract are sloughed off as they wear out (every 3 to 6 days) and are digested along with food, but this is also recycling. Skin cells from the epidermis are sloughed off and lost.
 

Offline tangoblue

  • Sr. Member
  • ****
  • Posts: 301
  • RANDOMNESS RULES!!!
    • View Profile
Where do dead cells go to?
« Reply #3 on: 27/10/2010 16:24:46 »
Hm, iv'e never heard of a proteosome. can i ask if it does anything else?
 

SteveFish

  • Guest
Where do dead cells go to?
« Reply #4 on: 27/10/2010 18:50:44 »
Tangoblue:

Proteosomes are very large multisubunit proteins (~20nm diameter, ~60nm long) that exist in many copies in the cytosol. Their function is digesting unwanted proteins in the cytosol with a primary duty of recycling proteins that were translated in the cytosol, but are being downregulated or were unable to fold properly. There are mechanisms in the cytosol that recognize and tag proteins that need to be recycled. One well known tag is ubiquitin. Proteosomes have a region that recognizes and binds the tag, another region that uses ATP to transport the protein into the proteosome lumen where many hydrolytic enzymes expose their active regions. The resulting amino acids and peptides can then be reused.

In terms of the original question, a large proportion of our cells die by the process of apoptosis where the cell sort of commits suicide. This process can be triggered by internal cellular mechanisms or when an immune cell provides a trigger if it determines that the cell is worn out, is infected by viruses or bacteria, is cancerous, or it farts and giggles during serious conversation. When a cell undergoes apoptosis it utilizes lysososomes and proteosomes to remove cellular machinery. Attached is a somewhat capricious illustration of a proteosome taken from EM photographs.

 

Steve
 

Offline tangoblue

  • Sr. Member
  • ****
  • Posts: 301
  • RANDOMNESS RULES!!!
    • View Profile
Where do dead cells go to?
« Reply #5 on: 28/10/2010 20:46:04 »
So is it similar to a lysosome, but much bigger?
 

SteveFish

  • Guest
Where do dead cells go to?
« Reply #6 on: 29/10/2010 01:54:18 »
It is difficult to keep oneself conscious of scale. The diameter of a lysosome is quite variable, but one that has matured would probably have a diameter (e.g. 0.6 microns) that is 10 times the long axis of a proteosome (60 nanometers).

More differences, beyond the fact that lysosomes are a membrane bound organelle while proteosomes are a large protein free in the cytosol, include the fact that proteosomes contain proteases while lysosomes contain these but also contain nucleases, glycosidases, lipases, phospholipases, phosphatases, and sulfatases.

Proteosomes are large enough to be considered as a new cellular organelle. When I first learned about them I was blown away.

Steve
 

Offline tangoblue

  • Sr. Member
  • ****
  • Posts: 301
  • RANDOMNESS RULES!!!
    • View Profile
Where do dead cells go to?
« Reply #7 on: 29/10/2010 18:47:54 »
Cool
 

The Naked Scientists Forum

Where do dead cells go to?
« Reply #7 on: 29/10/2010 18:47:54 »

 

SMF 2.0.10 | SMF © 2015, Simple Machines
SMFAds for Free Forums