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.
Plasma membrane is also a phospholipid bilayer which is essentially a biomembrane that can cover a cell or a cell organelle. For example, lysosome is a cell organelle which contains hydrolytic enzymes and it is bound by a single layer of plasma membrane. While, mitochondria, the powerhouse of the cell is bound by two layers of plasma membrane. Even the nucleus is membrane bound in eukaryotic cells. Hope that helps.