Flagella

Table of Contents

Definition: Flagella

Flagella are small hair-like structures involved in cell movement. The word “flagellum” means “whip”.

Flagella have a whip-like appearance that helps to keep the cell in the fluid. Some special flagella are used in a number of living things such as sensory organs that can sense changes in pH and temperature.

They are filamentous structures found in archaea, bacteria, and eukaryotes.

The archaeal flagella is not intomologous.
The bacterial flagella is a twisted, cord-like, sharp curved structure, which connects a rotating engine to its base and is made up of the protein flagellin. The shaft is located between the hook and the basal body passing through the protein rings in the cell membrane.
Eukaryotic flagella is a complex cell membrane that turns back and forth and is found in cancer cells, plant and animal gametes. It is made up of a protein called tubulin.

Flagella structure of bacteria

Flagella is a helical structure made up of flagellin proteins. The structure of the flagella is divided into three parts:

Basal Body
Ihuku
Filament
Basal Body
It is attached to the cell membrane and the cytoplasmic membrane.

It consists of rings surrounded by a pair of proteins called MotB. Rings include:

L-ring: The outer ring is encased in a layer of lipopolysaccharide and is found in gram + ve cells.
P-ring: Infused with a layer of peptidoglycan.
C-ring: Inserted into the cytoplasm
MS ring: Inserted into the cytoplasmic membrane

Ihuku

It’s a wide area at the bottom of the line.
It connects the filament to the motor protein at the base.
The length of the chicken is great for gram + ve bacteria.

Filament

A structure is similar to thin hair from a point.

Flagella species: There are four different types of flagella

Monotrichous

One flagellum at one end or another. These are known as polar flagellum and can rotate clockwise and counterclockwise. Clockwise movement moves the living one forward while the opposite movement of the clock pulls it backward.

Peritrichous

Several flagella are attached to the rest of the body. These are not polar flagella because they are found throughout the body. These flagella rotate opposite the clock and form a mass moving one organism in one direction. When another flagella breaks and begins to spin like a clock, the organism does not move in any direction and begins to fall.

Lophotricous

Several flagella at the end of one living thing or another. These are known as polar flagellum and can rotate clockwise and counterclockwise. Clockwise movement moves the living one forward while the opposite movement of the clock pulls it backward.

Amphitrichous

One flagellum in both ends of living organisms. These are known as polar flagellum and can rotate clockwise and counterclockwise. Clockwise movement moves the living one forward while the opposite movement of the clock pulls it backward.

Flagella activity

Flagella performs the following functions:

They help the living thing on the move.
They act as sensory organs to detect temperature and pH changes.
Few eukaryotes use flagellum to increase fertility.
Recent research has confirmed that the flagella are also used as a secret organelle. For example, in Chlamydomonas.

Cilia

It is grouped in the protozoans, Ciliata class, in the Ciliated epithelium of Metazoa, and other classes.

It is usually present on the outer surface of the body such as the caterpillar Mollusca, Annelida, and Nemertines, thus helping to escape.

It has structures and functions similar to those of the flagella, but the cilium is shorter and the movement is very different.

They are there in their abundance.
Cilia shows a beating movement.
Cilia usually cover the entire cell.
They combine into protozoans to form cirri.

These are present in protozoans, Metazoa choanocyte cells, and in other classes – in plants, gamete cells, and algae.

They are very tall.
Few in number.
Shows folded movement.
They are usually found at the end of a cell.
Flagella usually do not mix.