The key difference between phospholipids and sphingolipids is that the phospholipids are the most abundant lipids in the bio-membranes including the plasma membrane while the sphingolipids are the most abundant lipids in the nervous tissue.
Lipid is a macromolecule composed of glycerol and fatty acids. Lipids are mainly two types such as simple lipids and compound lipids. Structurally, simple lipids are esters of fatty acids with various alcohols. They include oils and fats. Compound lipids are the lipids which yield fatty acids, alcohols and other additional groups such as phosphoric acid, nitrogenous base carbohydrates, sulphur, amino acids, proteins, etc. upon hydrolysis. Likewise, Phospholipids and sphingolipids are two types of compound lipids, which are structural components. In addition, there are lipids called derived lipids. These are the hydrolytic products of simple and compound lipids that possess the physical characteristics if lipids.
CONTENTS
1. Overview and Key Difference
2. What are Phospholipids
3. What are Sphingolipids
4. Similarities Between Phospholipids and Sphingolipids
5. Side by Side Comparison – Phospholipids vs Sphingolipids in Tabular Form
6. Summary
What are Phospholipids?
Phospholipids are the most abundant lipids that serve as structural components of bio-membranes including cell membrane, lysosomal membrane, mitochondrial membrane, endoplasmic reticulum membrane, Golgi apparatus membrane, etc. Moreover, they are amphipathic molecules composed of a polar hydrophilic head and two non-polar, hydrophobic tails.
Figure 01: Phospholipids
When constructing a phospholipid molecule, one fatty acid tail removes and replaces it with a phosphate group. Together with the glycerol molecule, phosphate group makes the polar head of the phospholipid molecule. In addition, there is an additional molecule attached to a phosphate group. It can be a choline molecule, serine group, or an ethanolamine molecule. Consequently, based on these, phospholipids are three types namely phosphoglycerides, phosphor inositides and phospho sphingosides.
What are Sphingolipids?
Sphingolipids are a type of phospholipids that contain a long chain amino alcohol called sphingosine attached to a fatty acid chain. Hence, the core of the sphingolipids is the sphingosine. Moreover, these are the lipids commonly found in nervous tissue that involve with the signal transmission and cell recognition.
Figure 02: Sphingolipids
There are three subclasses of sphingolipids such as sphingomyelin, glycosphingolipids and gangliosides. Sphingomyelins are present abundantly in the cell membranes of animal cells especially in the myelin sheath of neurons. On the other hand, glycosphingolipids are a type of conjugated lipids present abundantly in the brain and spinal cord. The last type, gangliosides are the most complex sphingolipids that are present abundantly in ganglion cells of nervous tissue.
What are the Similarities Between Phospholipids and Sphingolipids?
- Phospholipids and Sphingolipids are lipids that involve in many functions in our body.
- They both are compound lipids that contain additional groups other than the fatty acids and glycerol molecules.
- Also, both serve as structural components of membranes and tissues.
- Furthermore, both contain phosphate groups in their molecules.
- Besides, both do not mix well with water.
What is the Difference Between Phospholipids and Sphingolipids?
Phospholipds and sphingolipids are compound lipids that slightly differ from each other. The major difference between phospholipids and sphingolipids is that the phospholipids are the most abundant structural component present in the biomembranes while the sphiongolipids are commonly found in the nervous tissue. Furthermore, sphingolipids contain sphingosine as the core molecule while it is not present in phospholipids.
The below infographic presents further facts on the difference between phospholipids and sphingolipids.
Summary – Phospholipids vs Sphingolipids
Phospholipids are compound lipids that are abundant in plasma membranes, and they form a lipid bilayer. On the other hand, sphingolipid is a type of phospholipids that are abundant in the nervous tissue. Consequently, they involve in signal transmission and cell recognition. Moreover, sphingolipids have sphingosine as their core molecule. Hence, this summarizes the difference between phospholipids and sphingolipids.
Reference:
1. “Phospholipids and Related Complex Lipids.” SMC Homepage. Available here
2.“Phospholipids.” Phospholipids – an Overview | ScienceDirect Topics. Available here
Image Courtesy:
1.”Phospholipid TvanBrussel.edit”By Superscience71421 – Own work, (CC BY-SA 4.0) via Commons Wikimedia
2.”Sphingolipids general structures”By LHcheM – Own work, (CC BY-SA 3.0) via Commons Wikimedia