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CH 4 & 5 Vocab
Term | Definition |
---|---|
Cell Theory | 3 essential parts: All living organisms are composed of one or more cells, cells are the basic units of structure and function in an organism, and cells come only from the reproduction of existing cells |
Plasma Membrane | Covers a cells surface and acts as a barrier between the inside and the outside of the cell. All materials enter or exit through here |
Cytoplasm | The region of the cell that is within the plasma membrane and that includes fluid, the cytoskeleton, and all the organelles except the nucleus |
Cytosol | The part of the cytoplasm that includes molecules and small particles, such as ribosomes, but not membrane bound organelles |
Nucleus | Control center. Membrane bound organelle that contains a cells DNA |
Prokaryotes | Organisms that lack a membrane bound nucleus and membrane bound organelles (Bacteria & Archaea) |
Eukaryotes | Organisms made up of one or more cells that have a nucleus and membrane bound organelles |
Organelles | Well defined intracellular bodies that perform specific functions for the cell |
Tissue | A group of similar cells and their products that carry out a specific function |
Organs | Groups of tissues that perform a particular job in an organism |
Organ System | A group of organs that accomplish related tasks |
Phospholipid Bilayer | Where phospholipids line up so that their heads point outward toward water, results in double layer |
Chromosomes | Structures in the nucleus made of DNA and protein |
Nuclear Envelope | Double membrane that surrounds nucleus (made up of two phospholipid bilayers) |
Nucleolus | Denser area in nucleus. Where DNA is concentrated when it is in the process of making ribosomal RNA |
Ribosomes | Organelles made of protein and RNA that direct protein synthesis in the cytoplasm |
Mitochondria | Tiny organelles that transfer energy from organic molecules to ATP |
Endoplasmic Reticulum (ER) | A system of membranous tubes and sacs. functions as a intracellular highway where molecules move from one part of the cell to another |
Golgi Apparatus | System of flattened, membranous sacs. Adds address labels to proteins to direct them to different parts of the cell |
Lysosomes | Vesicles that bud from the Golgi apparatus and that contain digestive enzymes. Breaks down cell when its time to die |
Cytoskeleton | A network of thin tubes and filaments that crisscrosses the cytosol. Gives shape to the cell and acts as a system of internal tracks |
Microtubules | Hollow tubes made of protein called tubulin. Hold organelles in place |
Microfilaments | long threads of beadlike protein acting and are linked end to end and wrapped around each other like two trans of rope. Contribute to cell movement |
Cilia & Flagella | Hairlike structures that extend from the surface of the cell and assist in movement |
Centrioles | Consist of two short cylinders of microtubules at right angles to each other and are situated in the cytoplasm near the nuclear envelope. Organize microtubules during cell division |
Cell Wall | A rigid layer that lies outside the cells plasma membrane. Allows some stuff to enter or exit (made of cellulose |
Central Vacuole | large fluid filled organelle that stores water and other materials. Make of my of there plant cells volume (90%) |
Plastids | Organelles that are surrounded by a double membrane and contain they own DNA |
Chloroplasts | Use light energy to make carbohydrates from C20 and water |
Thylakoids | System of flattened membranous sacs, contain chlorophyll |
Chlorophyll | Green pigment. Absorbs light and captures energy for the cell |
Passive Transport | Where substances can cross the cell membrane without any input of energy |
Diffusion | The movement of molecules from a area of higher concentration to lower |
Concentration Gradient | The difference in the concentration of molecules across a distance |
Equilibrium | Where the concentration of molecules will be the same throughout the space the molecules occupy |
Osmosis | Process by which water molecules diffuse across a cell membrane from an area of high concentration to low |
Hypotonic | When the concentration of solute molecules outside the cell is lower then the concentration in the cytosol (cell swollen) |
Hypertonic | When the concentration of solute molecules outside the cell is higher then the concentration in the cytosol (cell shrunk) |
Isotonic | When the concentrations of solutes outside and inside the cell are equal |
Contractile Vacuoles | Organelles that remove water |
Turgor Pressure | The pressure that water molecules exert against the cell wall |
Plasmolysis | Where the cell shrinks away from the cell walls and turgor pressure is lost |
Cytolysis | Where water diffuses into the cell causing them to burst |
Facilitated Diffusion | Process that is used for molecules that cannot readily diffuse through cell membranes |
Carrier Proteins | Specific proteins that assist molecules across the cell membrane in facilitated diffusion |
Ion Channels | Membrane proteins. Transport ions from higher to lower concentration |
Active Transport | The movement of molecules from an area of lower to high concentration. Requires a cell to expand energy |
Sodium Potassium Pump | Carrier protein. transport ions up their concentration gradients |
Endocytosis | The process by which cells ingest external fluid and other materials |
Vesicle | Membrane bound organelle that is digested by lysosomal enzymes |
Pinocytosis | Involves transport of solutes or fluids |
Phagocytosis | Movement of large particles or whole cells |
Phagocytes | Cells that use phagocytosis ton ingest bacteria and viruses that invade the body |
Exocytosis | The process by which a substance is released from the cell through a vesicle |