Replace 43

Path followed:

1.   Is the fault in the components that perform any physical action?

Answer: No

2.   Is the faulty component part of the mechanism’s body?

Answer: No

3.   Is the faulty component in the fuel system?

Answer: Yes

4.   Is the fault in the fuel filtration system?

Answer: Yes

5.   Is the fault in the fuel filtration components?

Answer: No

6.   Is the fault in fuel storage?

Answer: No

 

43) The fatty membranes of cells are capable of self-repair using a mechanism that involves Ca2+-dependent exocytosis.

Self-repair/replace: Our bodies are packages within packages. Every cell has a fatty membrane that self-assembles when placed in water, then reassembles when a breach occurs. Imagine a polymer wrapper that would heal when ripped during use, but would eventually decompose when placed in a compost heap.

An understanding of how cells replace large segments of missing surface membrane has come from studies that focused on the Ca²⁺-induced cytoplasmic events occurring beneath large disruption sites. Thus, the endothelial cell cytoplasm beneath disruption sites  was observed in electron micrographs to rapidly accumulate (< 5 s) a striking array of vesicles, most of them abnormally large. Moreover, lysosomeÐlysosome fusion, which results in the accumulation of large cytoplasmic vesicles, was observed to be induced by ionophore
treatment of fibroblasts. These results suggested that rapid vesicleÐvesicle fusion, in addition to exocytotic fusion, is initiated by disruption.

Microinjection of sea water into sea urchin eggs confirmed that exposure to external environments can indeed trigger an explosive fusion response among cytoplasmic membranes. When artificial sea water containing the natural level of Ca²⁺ (10 mM) was injected deep into egg cytoplasm, a barrier to fluorescein dextran flux formed around it as it left the microneedle tip; conversely, if cytoplasm was extruded into sea water, a barrier rapidly formed around the cytoplasmic island extruded. Both responses required Ca²⁺, and other divalent cations could not substitute for it.

AskNature. “Membranes self-repair.” 9 Jan 2015. Web. 20 Oct. 2017.

https://asknature.org/strategy/membranes-self-repair/#.Weo0i0zMyu4

McNeil, Paul L., and Mark Terasaki. “Coping with the inevitable: how cells repair a torn surface membrane.” Nature cell biology 3.5 (2001): E124-E124.

http://www.nature.com/ncb/journal/v3/n5/full/ncb0501_e124.html