Aresearcher who studies neurodegenerative diseases has found that dying neurons contains a high concentration of miss-folded proteins in their cytoplasm. further experiments demonstrated that the lysosomes are working properly in these neurons. according to this information, which cellular structure is responsible for this disease?

The cellular structure responsible for this disease is THE ENDOPLASMIC RETICULUM. 
In eurkaryotic cells, endoplasmic reticulum is very essential for the folding and trafficking of proteins. Increased protein synthesis and environmental insults usually leads to the misfolding of proteins by endoplasmic reticulum. The accumulation of misfolded proteins inside the cell is called endoplasmic reticulum stress.

The short-term effect of tar on the body is increased blood pressure.

In some developing nations the percentage of the animal protein from fish in the diet can be as high as 25 percent.  about 85% of fish caught is used for human consumption.  the remainder is converted into fishmeal and fish oil.