An alkene is a hydrocarbon containing double bonds. An alkyne is a hydrocarbon containing triple bonds. Ethene, C 2 H 4, is an example of an unsaturated hydrocarbon with a double bond.ethyne (acetylene), C 2 H 2 is an example of an unsaturated hydrocarbon with a triple bond.thene, C 2 H 4, is an example of an unsaturated hydrocarbon with a double bond. ethyne (acetylene), C 2 H 2 is an example of an unsaturated hydrocarbon with a triple bond.
Mitochondria and chloroplasts are also surrounded by membranes, but they have unusual membrane structures â specifically, each of these organelles has two surrounding membranes instead of just one. The outer membrane of mitochondria and chloroplasts has pores that allow small molecules to pass easily.
These ions are released from the smooth endoplasmic reticulum. SUMMARY. Organelles called ârough endoplasmic reticulumâ and âsmooth endoplasmic reticulumâ are separate networks of membrane enclosed flattened tubules found in eukaryotic animal and plant cells.t is âsmoothâ because it is not studded with ribosomes and is associated with smooth slippery fats. CELLS NEED THE ROUGH AND THE SMOOTH. Think of a cell as a âmultitude of membranesâ we said in an earlier section. This statement certainly applies to the endoplasmic reticulum an organelle found in eukaryotic cells.