Cytoskeleton facts for kids
Quick facts for kids Cell biology |
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Components of a typical animal cell:
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The cytoskeleton is a tiny network of fibers inside cells. It acts like a skeleton and muscles combined. It is found in the cytoplasm of all living cells, including bacteria and archaea. In eukaryotic cells, it reaches from the cell nucleus to the outer cell membrane. It gives cells their shape. It also helps them move, divide, and carry important cargo.
Scientists once thought cells were just filled with a simple jelly. In 1903, scientist Nikolai K. Koltsov suggested that tiny tubes shaped the cell. In 1931, French scientist Paul Wintrebert helped make the word popular. Later, in 1992, researchers proved that simple prokaryotic cells have one too!
Contents
Main Parts of the Eukaryotic Cytoskeleton
Eukaryotic cells contain three main kinds of fibers. Each part has a special job.
Microfilaments
Microfilaments are the thinnest fibers, measuring about 7 nanometers wide. They are made of a protein called actin. These tiny ropes help cells change shape and move around. They also power muscle contraction. Inside your muscle cells, a motor protein called myosin pulls along actin threads. This pulling makes your muscles tighten and work.
Intermediate Filaments
Intermediate filaments are medium-sized fibers about 10 nanometers wide. They are tough and act like strong cables. They protect the cell from stretching or tearing apart. One famous type is keratin, which makes skin, hair, and nails strong. These filaments also hold each organelle, such as the nucleus, safely in place.
Microtubules
Microtubules are the largest parts. They look like hollow drinking straws and measure 25 nanometers across. They are built from a protein called tubulin. Microtubules act like tiny railroad tracks inside the cell. Helper proteins called motor proteins carry vesicles and organelles along them.
Microtubules also make up whip-like hairs called cilia and flagella. These hairs beat back and forth to push cells forward. During cell division, microtubules build a machine called the mitotic spindle. This tool pulls chromosomes apart so two new cells can form.
Other Cool Jobs of the Cytoskeleton
The cytoskeleton helps living things in many ways:
- Cell movement: White blood cells use it to crawl toward germs.
- Taking in food: It helps cells swallow particles.
- Cytoplasmic streaming: In big plant cells, it stirs the fluid inside to spread nutrients.
- Cell wall building: It helps plants and bacteria build strong outer walls.
Prokaryotic Helpers
Prokaryotes do not have the exact same fibers as bigger cells. Instead, they have similar helper proteins. A protein called FtsZ acts like tubulin. It builds a ring to help bacteria divide. Another protein called MreB works like actin to keep bacteria shaped like rods. These tiny structures prove that even the simplest cells use a skeleton!
Images for kids
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Structure of an actin microfilament
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Actin filaments glowing inside mouse cells
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Structure of an intermediate filament
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Keratin intermediate filaments inside a cell
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Structure of a hollow microtubule
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Microtubules spreading out in a cell
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Cross section through cilia showing microtubules
See also
In Spanish: Citoesqueleto para niños
