Crenation Definition

In botany and zoology, “crenation” refers to the leaf-like scalloped margins of an item, such as a leaf or a shell. Crenation is a biological term that describes the creation of irregular notched edges on cells as a consequence of osmosis water loss.

Inside the body, cells are normally in an isotonic solution, which means that the concentration of solute and water inside and outside the cells is the same. Water moves in and out at a steady pace, keeping a similar osmotic pressure throughout the semipermeable membrane, allowing the cells to retain their form. When this balance is upset by the presence of a greater solute concentration in the solution, a hypertonic environment is created, causing intracellular water to flow out. The cells begin to shrink, and the cell membrane develops aberrant spikes and notches. Crenation is the term for this procedure.

Examples of Crenation

Red Blood Cell Crenation

Crenation is a process in which red blood cells lose their capacity to maintain an isotonic condition as a result of ionic alterations in the blood or defects in the cell membrane. Echinocytes and acanthocytes are the two forms of crenated red blood cells. Both of these cells have a rounder shape with spiny spikes on the cell surface, rather than the normal rounded biconcave shape.

The spines of echinocytes are small, homogeneous, and evenly spaced. Despite the fact that they have enough haemoglobin to survive, their presence indicates the presence of an underlying illness. Crenation of this sort is typically reversible and may be induced by ionic imbalances, such as high pH or calcium concentrations, or illnesses, such as uremia or pyruvate kinase deficiency, that cause cellular loss of potassium and water. It might also be an adverse effect of taking certain medications or chemotherapy medicines.

Spines on the cell membrane of acanthocytes have an unequal and irregular distribution, quantity, and length. The uneven shape is produced by changes in membrane lipids as a consequence of disorders such as abetalipoproteinemia, which produce aberrant lipid concentrations in the blood as well as an inability to produce specific lipoproteins that are essential for cell membranes. Other disorders that have the same impact include vitamin E insufficiency, liver disease, and malabsorption. This form of crenation cannot be reversed.

Food Pickling

A further example of crenation in everyday life is food pickling. Cucumbers, for example, are pickled in acidic solutions, allowing water to flow out and the typical shrinking of the crenation process.

Related Biology Terms

• Diffusion: Diffusion is the movement of molecules in a passive manner as a consequence of concentration gradients.
• Osmosis: The transfer of solvents from high-concentration regions to low-concentration areas over a semi-permeable barrier is known as osmosis. 
• Isotonic: a solution having the same concentration of intracellular and external solutes, resulting in an equilibrium in which water may easily pass across a semi-permeable membrane without altering concentration levels.
• Hypertonic: a solution with a greater concentration of extracellular solutes.

Quiz

1. A red blood cell is placed into different solutions. Which scenario will likely result in crenation?

1. Placed in an isotonic solution
2. Placed in a solution with a very high concentration of solute
3. Placed in a solution with a very low concentration of solute
4. None of the above

Answer to Question #1

B is correct. Crenation can only occur when water is lost from the cell. A would have no effect on the red blood cell, and C would cause the cell to explode from excess water entering the cell.

2, Reversible crenation and uniform spikes on red blood cells are characteristic of which type of cell?

1. Erythrocytes
2. Acanthocytes
3. Echinocytes
4. None of the above

Answer to Question #2

C is correct. Echinocytes possess uniform spikes on the membrane, and the crenation is usually reversible. A is another name for red blood cells, and B has abnormal spikes on the membrane due to lipid membrane abnormalities, and the crenation is irreversible.

3. Which of the following diseases does not cause the formation of echinocytes? 

1. Liver disease
2. Pyruvate kinase deficiency
3. Abetalipoproteinemia
4. Vitamin E deficiency:

Answer to Question #3

B is correct. Pyruvate kinase deficiency is only known to cause the formation of echinocytes.