Biology - Phospholipid & Lipid
Phospholipid & Lipid 又有咩分別&係咩黎呢?
而Phospholipid bilayer & Lipid bilayer 又有咩分別&係咩黎呢?
- 己式庚辛Lv 71 十年前最愛解答
lipid is a molecule composed of product of condensation reaction between glycerol (proapne-1,2,3-triol) and fatty acids. it is generally non-polar in nature. its major cellular functions are insulation, providing energy and as raw material in biosynthesis (of, for example, phospholipid).
phospholipid is siimilar to lipid -- however, one of the fatty acids on glycerol is replaced by a phosphate, which bears negative charge. therefore it is polar on the phosphate head and non-polar at the fatty acid chains. its shape is like a fat boy (round ionic head) with two long legs (alkyls of fatty acids). its major use is to build cell membranes.
there's no "lipid bilayer".
phospholipid bilayer is the structure of cell membranes: phospholipid molecules are arranged in parallel, with all ionic heads facing to one direction and tails to another, forming a layer. two layers are combined by "sticking" the alkyl chains of fatty acids together, leaving the ionic heads outside.
therefore, you gets a single layer of "bilayer", with all polar heads sticking on its both surfaces.
2010-09-26 19:13:17 補充：
like dissolves like. lipid has no such properties, so i guess they'll just fuse together to get a layer / a droplet.
what do you think? please correct me if i'm wrong.
- 1 十年前
Well................. Phospholipid belongs to the group of Lipid..... Why "Lipid bilayer" not present????資料來源： Myself