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cell organelles

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An organelle is a specialized subunit within a cell, having a specific function, and separately enclosed within its own lipid membrane. The name organelle comes from the idea that these structures are to cells what an organ is to the body. Listed below are the organelles, their structure and functions: The Cell Wall: (Found only in prokaryotic cells). The cell wall is only found in plants and is what separates plant cells from animal cells. It is mainly made from cellulose, which provides a stiff and rigid environment for the cell to live in. The cell wall is a wall that allows the circulation and distribution of water, minerals and other small molecules in and out of it. It provides rigid building blocks so that stable structures can be produced. This gives the cell a stable area and self contained environment. Lastly it provides a storage site and controls the development of tissues within the cell. The Cell Membrane: A cell's defining boundary. All cells, prokaryotic or eukaryotic, have a membrane that envelops the cell. It consists of two membranes and the space in between is called the intercellular space. This membrane separates a cells interior from its environment. ...read more.


Function: The main function of the nucleus is to maintain the condition of genes and control the activities of the cell. Mitochondria: (the power generators). Structure: A mitochondrion range from 1 to 10 micrometers (�m) in size and contain membranes composed of phospholipid bilayers and proteins. These membranes, however, have different properties. There are 5 compartments within the mitochondrion: * The outer membrane * The Inter membrane space (the space between the outer and inner membranes) * The inner membrane * The cristae space (formed by in foldings of the inner membrane * The matrix (space within the inner membrane). Function: Mitochondria occur in various numbers, shapes, and sizes in the cytoplasm of all eukaryotic cells. They play a critical role in generating energy in the cell and are involved in other processes such as cell signalling, cellular differentiation, apoptosis, as well as the control of the cell cycle and cell growth. Chloroplasts: (the power generators). Structure: Chloroplasts are the counter-part of the mitochondria and are often involved in storage. They are flat discs usually 2 to 10 micrometers in diameter and 1 micrometer thick. The chloroplast consists of an inner and an outer phospholipid membrane. ...read more.


Function: The centrosome is the main micro tubule organizing centre of the cell, (a key component of the cytoskeleton). It directs the transport through the ER and the Golgi apparatus. The mother centriole, the one that was inherited from the mother cell, also has a central role in making cilia and flagella. Centrioles: (Makes up the Centrosomes). Structure: An associated pair of centrioles, arranged at right angles to each other, makes the compound structure known as the Centrosome. The walls of each centriole are composed of nine triplets of microtubules. Function: Centrioles can be used in forming motility organelles such as the flagella or cilia. In replication, centrioles help with reproduction. Cytoskeleton: (A cells scaffold). Structure: The eukaryotic cytoskeleton is composed of microfilaments, intermediate filaments and microtubules. There is a great number of proteins associated with them, each controlling a cell's structure by directing, bundling, and aligning filaments. Function: The cytoskeleton is a cellular "scaffolding" or "skeleton" contained within the cytoplasm. It organizes and maintain the cell's shape, anchors organelles in place and moves parts of the cell in processes of growth and mobility. Vacuoles: (Storage). Structure: Vacuoles are often described as liquid filled space and are surrounded by a membrane. Function: Vacuoles can serve a variety of secretory, excretory, and storage functions. ...read more.

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