Flagella and Cillia.pdf

Many cells use flagella to move around. Like many algae, Chlamydomonas has an eye spot that responds to light and affects the way the flagella beats, steering the cell toward or away from it. Prokaryotic Flagella – are made of a protein called flagellin and are anchored to the cell membrane by a bas...

Many cells use flagella to move around. Like many algae, Chlamydomonas has an eye spot that responds to light and affects the way the flagella beats, steering the cell toward or away from it. Prokaryotic Flagella – are made of a protein called flagellin and are anchored to the cell membrane by a basal body. They rotate like propellers to move the bacterium forward or backward. Eukaryotic Flagella – they are composed of microtubules. These flagella move in a whip-like fashion, powered by the motor protein dynein which causes the microtubules to slide against each other resulting in the bending motion that propels the cell forward. Many proteins have flagella of different lengths and functions. Euglenoid called Fakus is swimming in the direction of its longer flagella. These relatives of fakers also have two flagella which function differently. One beats in a coil around the cell. The other, as in fakus, extends forwards. Other algae have more than two flagella. This cell has eight inserted into a deep pit. It normally swims very rapidly and must be slowed down to have its picture taken. Cilia – short hair-like structures that extend from the surface of many Eukaryotic cells. Cilia are typically numerous and cover large portions of the cell surface. It plays a role in both sensory and movement functions. Large proteins like paramecium swim rapidly using hundreds or even thousands of flagella or cilia as they are usually called. They are very agile as they search amongst the pond debris for food. The beating cilia are coordinated, and the direction of the beating is reversed when the soul changes the direction it wants to go. Many protists also use their cilia to create currents for feeding carrying nearby organisms close enough to be eaten. The cells of some tissues in animals have multiple cilia, like these cells cultured from lung tissue. The activity of the cilia is coordinated so that liquid or mucilage can be moved long distances over the surface of the tissue. Flagella and cilia contain a core of microtubules using polarized light for imaging the cells, the microtubules show up as a dark or light fiber inside each cilium.