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7th Unit 2
Cell structure and Function Key Terms
Term | Definition |
---|---|
Cell theory | A principle that describes the cell as the fundamental unit of all living organisms. A principle that describes the properties of an organism as the sum of the properties of its component cells. |
Cell | The smallest structural unit of an organism that is capable of independent functioning, consisting of one or more nuclei, cytoplasm, and various organelles, all surrounded by a semipermeable cell membrane. |
Cancer | Abnormal cell growth caused by uncontrolled cell division. |
Cell membrane | The semipermeable membrane that encloses the cytoplasm of a cell. It is also called the plasma membrane. |
Cell wall | The rigid outermost cell layer found in plants and certain algae, bacteria, and fungi but characteristically absent from animal cells. |
Centrioles | One of two cylindrical cellular structures that are composed of nine triplet microtubules and form the asters during mitosis. |
Chloroplasts | A chlorophyll-containing plastid found in algal and green plant cells. |
Cytoplasm | The clear gel-like fluid found outside the nucleus of a cell. |
Deoxyribonucleic acid (DNA) | A nucleic acid that carries the genetic information in the cell and is capable of self-replication and synthesis of RNA. |
Endoplasmic reticulum | A membrane network within the cytoplasm of cells involved in the synthesis, modification, and transport of cellular materials. |
Food vacuole | A vesicle in which water, nutrients, food, and other materials are stored. |
Golgi complex | A complex of parallel, flattened sacs, vesicles, and vacuoles that lies adjacent to the nucleus of a cell and is concerned with the formation of secretions within the cell. Also called Golgi apparatus. |
Lysosomes | Single, membrane-bound sacs that contain digestive enzymes. |
Mitochondria | A spherical or elongated organelle in the cytoplasm of nearly all eukaryotic cells, containing enzymes important for cell metabolism, including those responsible for the conversion of food to usable energy. |
Nucleus | A large, membrane-bound, usually spherical protoplasmic structure within a living cell, containing the cell's hereditary material and controlling its metabolism, growth, and reproduction. |
Nucleolus | A small, typically round granular body composed of protein and RNA in the nucleus of a cell. It is usually associated with a specific chromosomal site and involved in ribosomal RNA synthesis and the formation of ribosomes. |
Organelles | A differentiated structure within a cell, such as a mitochondrion, vacuole, or chloroplast. It performs a specific function. |
Ribosome | Small particles, present in large numbers in every living cell, whose function is to convert stored genetic information into protein molecules. |
Nutrients | A source of nourishment, especially a nourishing ingredient in a food. |
Interphase | The phase in the life cycle of a cell wherein the cell grows in size, replicates its DNA, and prepares for cell division |
Prophase | In eukaryotic cells, the chromosomes condense and the nuclear membrane begins to disappear. |
Metaphase | In eukaryotic cells, the chromosomes line up in the middle of the cell. |
Anaphase | In eukaryotic cells, the spindle fibers pull the sister chromatids to opposite ends of the cell. |
Telophase | In eukaryotic cells, a nuclear membrane begins to form around each of the two new daughter cells. |
Cytokinesis | The splitting of the cytoplasm. |