UNIT+2-+CELL

CELLS
Cells in any cellular organisms life are very important. They are so important because in a cellular body there are millions of cells in it. Taking a human body for example we are made of millions possibly billions of nucleus's. A nucleus a large membrane-enclosed structure that contains the cell's genetic material in the form of DNA. Just to note a membrane is a thin layer of material that serves as a covering or lining. Another important fact about the nucleus is that it controls basically all of the cell's activities. Think of a nucleus as a the brains in the cell body it runs everything in your body. Also other cells such as white blood cells kill viruses which can cause any person to get very sick because viruses most attack the nervous system. These cells come and clean up the mess that virus's do in the body. There are parts of the cell that are very important to remember and they are the cell wall, nucleus, nucleolus, ribosome, vacuole, cell membrane, Smooth and Rough endoplasmic reticulum, and chloroplast. There is an example of both an animal cell and plant cell below.


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Cell- Collection of living matter enclosed ny a barrier that separates the cell from its surroundings; basic unit of all forms of life.
 * Cell Theory- Idea that all living things are composed of cells, cells are the basic unit of structure and function in living things, and new cells are produced from existing cells.
 * Nucleus- The center of the atom which contains the protons and neutrons; in cells, structure that contains the cell's genetic material (DNA) and controls the cell's activities.
 * Eukaryote- Organism whose cells contain nuclei.
 * Prokaryote- Unicellular organism lacking a nuleus.
 * Organelle- Specialized structure that performs important cellular functions within a eukaryotic cell.
 * Cytoplasm- Material inside the cell membrame- not including the nucleus.
 * Nuclear Envolope- Layer of two membrames that surrounds the nucleus of a cell.
 * Chromatin- Granular material visible within the nucleus; consists of DNA tightly coiled around proteins.
 * Chromosome- Thread like structure within the nucleus containing the genetic information passed down from one generation to the next.
 * Nucleolus- Small, dense region within the nuclei in which the assembly of protons begins.
 * Ribosome- Small particle in the cell in which proteins are assembled.
 * Endoplasmic Reticulum- Internal membrame system in cells in which lipid components of the cell membrame are assembled.
 * Golgi Apparatus- Stack of membrames in the cell that modifies, sorts, and packages proteins.
 * Lysosome- Cell organelle filled with enzymes needed to break down certain materials in the cell.
 * Vacuole- Cell organelle that stores materials such as water, salt, and proteins and carbohydrates.
 * Mitochondrion- Cell organelle that converts the chemical energy stored in food into compounds that are more convenient for the cell to use.
 * Chloroplast- Organelle found in cells of plants and some other organisms that captures the enrygy from sunlight and converts it into chemical energy.
 * Cytoskeleton- Network of proteins filaments within some cells that helps the cell maintain its shape and is involved in many forms of cell movement.
 * Centriole- One of two tiny structures located in the cytoplasm of animal cells near the nuclear envelope.
 * Cell Membrame- Thin, flexible barrier around the cell; regulates what enters and leaves the cell.
 * Cell Wall- Strong supporting layer around the cell membrame in ppants, algae, and some bacteria.
 * Lipid Bilayer- Double-layered sheet that forms the core of nearly all cell membrame.
 * Concentration- The mass of solute in a given volume of solution, or mass/volume.
 * Diffusion- Process by which molecules tend to move from an area where they are more concentrated to an area where they are less concentrated.
 * Equilibrium- When the concentration of a solute is the same throughout a solution.
 * Osmosis- Diffusion of water through a selectively permeable membrame.
 * Isotonic- When the concentration of two solutions is the same.
 * Hypertonic- When comparing rwo solutions, the solution with the greater concentration of solutes.
 * Hypotonic- When comparing two solutions, the solution with the lesser concentration of solutes.
 * Facilitated Diffusion- Movement of specific molecules across cell membrames through protein through channels.
 * Active Transport- Energy-requiring process that moves material across a cell membrame against a concentration difference.
 * Endocytosis- Process by which a cell takes material into the cell by infolding of the cell membrame.
 * Phagocytosis- Process in which extensions of cytoplasm surround and engulf large particles and take them into the cell.
 * Pinocytosis- Process by which a cell takes in liquid from the surrounding environment.
 * Exocytosis- process by which a cell releases large amounts of material.
 * Cell Specialization- The process in which cells develop in different ways to perform different tasks.
 * Tissue- Group of similar cells that perform a particular function.
 * Organ- Group of tissues that work together to perform closely related functions.
 * Organ System- Group of organs that work together to perform a specific function.