Description | Function | Where | |
---|---|---|---|
Cell wall | Outermost layer of a plant cell composed of cellulose and other complex carbohydrates. | Helps to support and protect the cell. | P |
Flagella (flagellum) | Long and scarce threadlike structures that extend from the surface of the cell. | Used for movement of the cell or to move fluids over the cell’s surface for absorption. | A |
Cilia (cilium) | Short and abundant threadlike structures that extend from the surface of the cell. | Used for movement of the cell or to move fluids over the cell’s surface for absorption. | A |
Cell membrane | Outer layer composed of lipids and proteins. | Controls the permeability of the cell to water and dissolved substances. | A, P |
Cytoplasm | Viscous fluid mixture that occupies most of the cell’s interior. Wraps the nucleus and contains biomolecules, organelles and a protein fiber network (the cytoskeleton). | Medium in which organelles and other internal structures exist in. The fiber network makes the cytoskeleton, which supports the shape of the cell and anchor organelles to fixed positions. | A, P |
Mitochondria (mitochondrion) |
Elongated organelles enclosed in a double membrane, the inner one with folds called cristae. | Sites of cellular respiration, which converts sugars and fats into energy through oxidation. | A, P |
Chloroplasts | Elongated organelles enclosed in a double membrane and with vesicles containing chlorophyll. | Sites of photosynthesis. | P |
Ribosomes | Tiny organelles composed of proteins and RNA, not enclosed in a membrane. Some are free in the cytoplasm, some are attached to endoplasmic reticulum. They are the only organelles present in all cells, including prokaryotics. | Sites of protein synthesis. | A, P |
Endoplasmic reticulum | Extensive system of internal membranes. May be smooth or rough: the latter has ribosomes attached to its membrane. | Site of synthesis, modification and transport of various organic biomolecules. | A, P |
Golgi apparatus | Flattened stacks of membranes. | Used in the collection, packaging, and distribution of synthesized molecules. | A, P |
Secretory vesicles | Membrane enclosed sacks created at the Golgi apparatus. | These structures contain cell secretions, like hormones and neurotransmitters. The secretory vesicles are transported to the cell surface where they release those substances outside the cell (exocytosis). | A, P |
Vacuoles | Elongated organelles enclosed in a membrane. Few and large in plant cells. | Used to store sap (water and sugars) or waste products. | A, P |
Lysosomes | Spherical organelles enclosed in a membrane. | Contain digestive enzymes for breaking down old cellular components or ingested food (smaller cells, big macromolecules). | A, P |
Centrosome | A pair of hollow tubes (the centrioles) surrounded by protein fibers in a star-like arrangement. Plant cells have an equivalent structure. | Move and organise chromosomes during mitosis and meiosis. | A |
Nucleus | Double membrane structure that encases chromatine. | Controls the cellular activity. | A, P |
Chromatine | Long strands of DNA and protein. During cell division it is packaged into chromosomes. | The DNA stores hereditary information in small units of information called genes, and expresses it. | A, P |
Nucleolus | Highly condensed chromatine loops. | Area were ribosomes are manufactured. | A, P |
ACTIVITY
Make a schematic drawing reproducing the structure of a eukaryotic cell. Paint each organelle with a different color and name. Try putting in a short, or an attached table, the function of each. CLUE
- Inside a Cell (University of Utah)