There are three types of unsaturated hydrocarbons: alkenes, alkynes and aromatic hydrocarbons. Alkenes have one or more carbon-carbon double bond. Alkynes have one or more carbon-carbon triple bond, and aromatic hydrocarbons have a benzene or aromatic ring in their structure.ydrocarbons are compounds that only consist of the elements hydrogen and carbon. In this lesson, we will focus on one type of hydrocarbon: unsaturated hydrocarbons, and its three types-alkenes, alkynes and aromatic hydrocarbons.
In eukaryotes the organelles of the endomembrane system include: the nuclear membrane, the endoplasmic reticulum, the Golgi apparatus, lysosomes, vesicles, endosomes and the cell membrane.
The nucleus, the largest organelle in eukaryotic cells, is surrounded by two membranes, each one a phospholipid bilayer containing many different types of proteins. The inner nuclear membrane defines the nucleus itself.he various techniques described earlier have led to an appreciation of the highly organized internal structure of eukaryotic cells, marked by the presence of many different organelles (Figures 5-42 and 5-43). Here we present a brief overview of the major organelles.