Lysosomes
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− | Lysosomes are [[Organelles|organelles]] found in all [[Animal cells|animal cells<ref>Davidson M.W., Florida State University, 1995. Cited: 24/11/2016 (Available from: https://micro.magnet.fsu.edu/cells/lysosomes/lysosomes.html)</ref> | + | Lysosomes are [[Organelles|organelles]] found in all [[Animal cells|animal cells]]<ref>Davidson M.W., Florida State University, 1995. Cited: 24/11/2016 (Available from: https://micro.magnet.fsu.edu/cells/lysosomes/lysosomes.html)</ref> and less commonly found in plant cells<ref>Sullivan J.A., CELLS Alive!, 1994. Cited: 24/11/2016 (Available from: http://www.cellsalive.com/cells/cell_model.htm)</ref>, that consist of [[Hydrolytic digestive enzymes|hydrolytic digestive enzymes]] enclosed by a single-layer membrane ([[Vesicle|vesicle]])<ref>Davidson M.W., Florida State University, 1995. Cited: 24/11/2016 (Available from: https://micro.magnet.fsu.edu/cells/lysosomes/lysosomes.html)</ref>. |
− | Their purpose is to break down substances that are harmful or no longer useful for the cell<ref>Davidson M.W., Florida State University, 1995. Cited: 24/11/2016 (Available from: https://micro.magnet.fsu.edu/cells/lysosomes/lysosomes.html)</ref>, or even entire organelles<ref>Alberts B., Johnson A., Lewis J., Morgan D., Raff M., Roberts K., Walter P., ‘Molecular Biology of the Cell’, 6th Edition, New York: Garland Science, Taylor &amp; Francis Group. 2015. Page 642</ref>, and recycle their components for later use by the cell<ref>Davidson M.W., Florida State University, 1995. Cited: 24/11/2016 (Available from: https://micro.magnet.fsu.edu/cells/lysosomes/lysosomes.html)</ref>. Lysosymes are present in greater numbers in [[White blood cells|white blood cells]], since they are needed to break down toxic substances and [[Bacterial meningitis|bacteria]] that have been taken in by [[Endocytosis|endocytosis]]<ref>Davidson M.W., Florida State University, 1995. Cited: 24/11/2016 (Available from: https://micro.magnet.fsu.edu/cells/lysosomes/lysosomes.html)</ref>. | + | Their purpose is to break down substances that are harmful or no longer useful for the cell<ref>Davidson M.W., Florida State University, 1995. Cited: 24/11/2016 (Available from: https://micro.magnet.fsu.edu/cells/lysosomes/lysosomes.html)</ref>, or even entire organelles<ref>Alberts B., Johnson A., Lewis J., Morgan D., Raff M., Roberts K., Walter P., ‘Molecular Biology of the Cell’, 6th Edition, New York: Garland Science, Taylor &amp;amp; Francis Group. 2015. Page 642</ref>, and recycle their components for later use by the cell<ref>Davidson M.W., Florida State University, 1995. Cited: 24/11/2016 (Available from: https://micro.magnet.fsu.edu/cells/lysosomes/lysosomes.html)</ref>. Lysosymes are present in greater numbers in [[White blood cells|white blood cells]], since they are needed to break down toxic substances and [[Bacterial meningitis|bacteria]] that have been taken in by [[Endocytosis|endocytosis]]<ref>Davidson M.W., Florida State University, 1995. Cited: 24/11/2016 (Available from: https://micro.magnet.fsu.edu/cells/lysosomes/lysosomes.html)</ref>. |
The hydrolytic enzymes found within the lysosomes are all produced in the [[Rough endoplasmic reticulum|rough endoplasmic reticulum]] (RER) and transported to the [[Golgi apparatus|Golgi apparatus]] for modification<ref>Davidson M.W., Florida State University, 1995. Cited: 24/11/2016 (Available from: https://micro.magnet.fsu.edu/cells/lysosomes/lysosomes.html)</ref>. They are then released from the Golgi apparatus inside vesicles<ref>Davidson M.W., Florida State University, 1995. Cited: 24/11/2016 (Available from: https://micro.magnet.fsu.edu/cells/lysosomes/lysosomes.html)</ref>. | The hydrolytic enzymes found within the lysosomes are all produced in the [[Rough endoplasmic reticulum|rough endoplasmic reticulum]] (RER) and transported to the [[Golgi apparatus|Golgi apparatus]] for modification<ref>Davidson M.W., Florida State University, 1995. Cited: 24/11/2016 (Available from: https://micro.magnet.fsu.edu/cells/lysosomes/lysosomes.html)</ref>. They are then released from the Golgi apparatus inside vesicles<ref>Davidson M.W., Florida State University, 1995. Cited: 24/11/2016 (Available from: https://micro.magnet.fsu.edu/cells/lysosomes/lysosomes.html)</ref>. | ||
− | The [[Membrane|membrane]] of lysosomes contain H+ [[ATPase|ATPases]] which actively pump [[Proton|protons]] from the [[Cytosol|cytosol]] into the [[Lumen|lumen]], using [[ATP|ATP]] as a source of [[ | + | The [[Membrane|membrane]] of lysosomes contain H+ [[ATPase|ATPases]] which actively pump [[Proton|protons]] from the [[Cytosol|cytosol]] into the [[Lumen|lumen]], using [[ATP|ATP]] as a source of [[Chemical energy|energy]]. This retains the internal pH of lysosomes at about 4.5 to 5, providing an [[Acid|acid]] environment for the optimal activity of hydrolytic enzymes contained within<ref>Alberts et al. Molecular Biology of the Cell. Sixth Edition. pg722-723 New York: Garland Science; 2015.</ref>. |
=== References === | === References === | ||
<references /> | <references /> |
Latest revision as of 14:09, 3 December 2016
Lysosomes are organelles found in all animal cells[1] and less commonly found in plant cells[2], that consist of hydrolytic digestive enzymes enclosed by a single-layer membrane (vesicle)[3].
Their purpose is to break down substances that are harmful or no longer useful for the cell[4], or even entire organelles[5], and recycle their components for later use by the cell[6]. Lysosymes are present in greater numbers in white blood cells, since they are needed to break down toxic substances and bacteria that have been taken in by endocytosis[7].
The hydrolytic enzymes found within the lysosomes are all produced in the rough endoplasmic reticulum (RER) and transported to the Golgi apparatus for modification[8]. They are then released from the Golgi apparatus inside vesicles[9].
The membrane of lysosomes contain H+ ATPases which actively pump protons from the cytosol into the lumen, using ATP as a source of energy. This retains the internal pH of lysosomes at about 4.5 to 5, providing an acid environment for the optimal activity of hydrolytic enzymes contained within[10].
References
- ↑ Davidson M.W., Florida State University, 1995. Cited: 24/11/2016 (Available from: https://micro.magnet.fsu.edu/cells/lysosomes/lysosomes.html)
- ↑ Sullivan J.A., CELLS Alive!, 1994. Cited: 24/11/2016 (Available from: http://www.cellsalive.com/cells/cell_model.htm)
- ↑ Davidson M.W., Florida State University, 1995. Cited: 24/11/2016 (Available from: https://micro.magnet.fsu.edu/cells/lysosomes/lysosomes.html)
- ↑ Davidson M.W., Florida State University, 1995. Cited: 24/11/2016 (Available from: https://micro.magnet.fsu.edu/cells/lysosomes/lysosomes.html)
- ↑ Alberts B., Johnson A., Lewis J., Morgan D., Raff M., Roberts K., Walter P., ‘Molecular Biology of the Cell’, 6th Edition, New York: Garland Science, Taylor &amp; Francis Group. 2015. Page 642
- ↑ Davidson M.W., Florida State University, 1995. Cited: 24/11/2016 (Available from: https://micro.magnet.fsu.edu/cells/lysosomes/lysosomes.html)
- ↑ Davidson M.W., Florida State University, 1995. Cited: 24/11/2016 (Available from: https://micro.magnet.fsu.edu/cells/lysosomes/lysosomes.html)
- ↑ Davidson M.W., Florida State University, 1995. Cited: 24/11/2016 (Available from: https://micro.magnet.fsu.edu/cells/lysosomes/lysosomes.html)
- ↑ Davidson M.W., Florida State University, 1995. Cited: 24/11/2016 (Available from: https://micro.magnet.fsu.edu/cells/lysosomes/lysosomes.html)
- ↑ Alberts et al. Molecular Biology of the Cell. Sixth Edition. pg722-723 New York: Garland Science; 2015.