The portion of the membrane system in eukaryotic cells that is responsible for the making lipids and breaking down toxic substances is the A) rough ER. B) smooth ER. C) ribosomal ER. D) semi-permeable ER.

B smooth er is the answer

The answer is smooth endoplasmatic reticulum. Smooth endoplasmic reticulum is involved in the production and metabolism of lipids and in the production of steroid hormones. Also, smooth endoplasmic reticulum converts organic chemicals to water-soluble products and that way detoxifies them.