Table
Structure and Function of Cell Organelles
Organelle | Structure | Function |
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Cell Wall | Found in plant cells only; mainly made up of cellulose and hemicellulose, chitin (fungus), protein (bacteria). |
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Nucleus | Contains DNA and protein; limited by a nuclear membrane in eukaryotic cells, nuclear membrane not found in prokaryotic cells, contains nucleolus; nucleoplasm contains chromatin material. |
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Mitochondria | Double membraneous, outer and inner membrane folded inside forming cristae; the inner surface of the inner membrane has a number of F1or elementary particles. |
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Plastids | Double membraneous structure, inner membrane in the form of thylakoids forming stroma and grana. They are of three types:
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Endoplasmic
| Membrane folds forming cisternae, vesicles and tubules; of two types SER (without ribosomes) and RER (with ribosomes). |
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Golgi Complex | Stacks of membranes in the form of cisternae, vacuoles and vesicles; in plant cells known as dictyosomes. |
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Lysosomes | Single membrane sacs containing hydrolytic enzymes; classified as primary lysosomes, secondary lysosomes, autophagic vacuoles and residual bodies depending upon the physiological state of their action. |
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Microbodies
| Small-sized organelles containing enzymes like catalyses and oxidases. Small spherical bodies having high deposits of fats and lipids; enzymes like acid phosphates are found. Small bodies found in the seeds of groundnut and castor (that contain fatty acids). |
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Ribosomes | Small bodies containing RNA and proteins; a group of ribosomes attached to a mRNA strand forms polyribosomes. |
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Centriole | Two dot-like bodies present near the nucleus; shows 9+0 pattern of arrangement of milcrotubules. |
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Cilia and Flagella | Surrounded by a membraneous covering; shows 9+2 pattern of arrangement of microtubules. |
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Microtubules and Microfilaments | Long, unbranched cylindrical tubes made up of proteins like tubulin and actin; forms net-work in the cytoplasm of the cell. | Transport of substances in higher organisms.
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Vacuoles | Unit membraneous bags filled with cell-fluids; membrane is known as tonoplast. |
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