Ceramides – Definition and Types

Ceramides

Ceramides form a family of naturally occurring waxy lipid molecules. They are similar to sterols and fats.  As a structural and signalling molecule, it helps make up a sizeable portion. A portion of the cell membrane of eukaryotic cells. Moreover, it was earlier assumed to be its exclusive purpose

However, it also signals actions within it. In other words, it helps in maintaining proliferation and differentiation. In addition to the programmed cell death (PCD) of cells. 

Moreover, they are mainly made up of a fatty acid, and sphingosine. Since they are what make up the sphingomyelin. It is one of the main lipids in the lipid bilayer of the membranes.

Moreover, it is but natural that they are found in such major concentrations. It is within the cell membranes.

Further, they are mainly found on the surface layers of our skin. And, these lipids control the water loss from our skin. In addition, save it from harmful substances going within.

Ceramide is also a key component of the vermix caseosa. It is a waxy cheese-like white substance that coats the skin of human infants upon birth.

As a result of its prominence in our skin epidermis. Further, it is now used as the main component in skin care products. Mainly for ageing or dry skin.

Ceramides Definition

Ceramides (CERs) are a structurally heterogeneous class of complex sphingolipids. Further, they consist of derivatives with phytosphingosine or sphingosine. Moreover, it is as a base bound to different fatty acids by an amide linkage.

It is found in the stratum corneum (SC) of the epidermis of the skin. It makes up around 40% of it.

The origin of the word ‘ceramide’ is from two Latin words- ‘cera’ meaning ‘wax’, and ‘amide’.

Types of Ceramides 

The ceramides in the human stratum corneum play some important physicochemical roles. Further, it helps maintain the skin barrier. In addition, maintain its water-retaining capacity.

Some ceramides within the human body, along with other similar lipids help in the keratinisation regulation. Further, ceramides that could be found in eukaryotic cells are of multiple kinds.

Some not yet found, but the human skin only has 9 varieties found in it.

List of Ceramides

We can categorise ceramides, or CERs, into multiple classes, like the following:

• α-hydroxy fatty acid (A)
• ω-hydroxy fatty acid (O)
• Non-hydroxy fatty acid (N)
• Ester-linked non-hydroxy fatty acid (E)
• Sphingosine (S)
• Phytosphingosine (P)
• Dihydrosphingosine (DS)
• 6-hydroxy-sphingosine moieties (H)

These further subdivide into 12 classes:

• Ceramide NDS or CER[NDS]
• Ceramide  NS or CER[NS]
• Next, Ceramide NP or CER[NP]
• Ceramide NH or CER[NH]
• Ceramide ADS or CER[ADS]
• Further, Ceramide AS or CER[AS]
• Ceramide AP or CER[AP]
• Ceramide AH or CER[AH]
• Then, Ceramide EODS or CER[EODS]
• Ceramide EOS or CER[EOS]
• Ceramide EOP or CER[EOP]
• Finally, Ceramide EOH or CER[EOH]

Solved Question for You

Q:  Ceramides are a key component of which liquid?

1. CSF
2. Lymph
3. vermix caseosa
4. Ascites

Solution: The correct option is ‘c’. They are a key component of the vermix caseosa. It is a waxy cheese-like white substance. It coats the skin of human infants upon birth.