Basic Cell Structures

You'll find below a simple review of some basic cell structures, as well as a comparison of Eukaryotes and Prokaryotes; Plant and Animals.


Cell Structures... Prokaryotic Cells vs. Eukaryotic Cells... Comparing and Contrasting Prokaryotic, Animal, and Plant cells...

Cell Structures

Cytoskeleton Microfilaments Microtubules Cilia Flagella Basic Cross Section

The Nucleus Nuclear envelope Nuclear pores Chromosomes Chromatin Nucleolus

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The cytoskeleton is the integrated network of fibers (microfilaments and microtubules) in the cytoplasm that controls cell circulation, cell shape, cell mobility, and holds organelles in place

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(actin filaments)

Microfilaments (part of the cytoskeleton) are fibers of twisted F-actin (fibrous actin) chains of G-actin (globular actin) monomers. They are used in muscle contraction by interacting with myosin. They also function in cell division and movement.

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Microtubules (part of the cytoskeleton) are hollow tubes of globular proteins calles tubulins. In most cells the microtubules radiate out from the microtubule organizing center (near the centrioles in animal cells). These are used for cell support and structure. They also play a part in movement of organelles and chomosome seperation.

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A cellular appendage used for movement in most cases. Cilia have the basic structure of flagella but are smaller and much more abundant on one cell. Cilia cause movement by a back and forth motion, like rowing a boat.

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A cellular appendage used for mobility. Flagella have the same structure as cilia, but are larger, and usually a cell only has one, two, or sometimes three flagella. Movement by flagella utilizes a undulating (snakelike) pattern.

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Basic "9+2" structure of cilia and flagella

"9+2" - Nine outer microtubule pairs, two inner microtubules.

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The Nucleus

The brain of the cell that contains the genetic material (chromosomes) that controls cell processes.

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Nuclear Envelope

A double phospholipid bi-layer membrane with embedded proteins that encloses the parts of the nucleus. The inner membrane helps hold the shape of the nucleus, and may help in the organization of genetic matter. The nuclear envelope is perforated by nuclear pores.

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Nuclear Pores

Openings through the nuclear envelope at which the two membranes are fused that work in macromolecule (such as ribisomal proteins and subunits) transportation into, and out of the nucleus.

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Structures of proteins and DNA in the nucleus.

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The mass of chromosomes in the nucleus.

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A structure within the nucleus that functions in the synthesis of ribosomes. The structure is a mass of granules and fibers, consisting of nuclear organizers (specialized regions of DNA for ribosomal synthesis), RNA, and proteins.

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Prokaryotic Cells vs. Eukaryotic Cells

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Comparing and Contrasting Prokaryotic, Animal and Plant Cells

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This page was last altered 8/14/01