 | Term | Definition |
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cell adhesion molecules |
specific membrane proteins that allow cells to identify the tissue that they begin with, cells that belong to a specific type of tissue will have cell adhesion molecules that they are complimentary to each other, these proteins will fit into eachother and attach the individual cells to other cells in their specific tissue. if one of these cells break away from their tissue, these cell adhesion molecules will evolve into an enzyme that will initiate apotosis(programmed cell death) in order to prevent a cell from a different tissue type from existing in a tisse where it does not belong |
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metastasis |
spread of cancer cells |
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cell identification markers |
each cell wihin a living organism has specific shape protein identification markers that tell the immune system of the organism that the cell belongs to it. a foregin cell will not have the same identification protein and will be attacked by the immune system if it enters the organism (an important class of these markersare major histocompatibility "MHC" proteins) |
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selective permeability of the plasma membrane |
a] the lipid bilayer acts as a barrier to most water soluble substances and prevents their movement through the membrane, b] each cell will incorporate into the structure of its plasma membrane specifically structured channel and transort proteins that are specifically designed to transport specifically desired substances accross the cell membrane. te specific types of channel and transport proteins that exist witin the plasma membrane are determined by the cell |
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carbohydrates of the cel membranel |
generally occur attached to proteins(glycoproteins) and lipids(glycolipids). other carbohydrate compounds known as proteoglycans(carbohydrate substances bound together by protein cores) are also attached to the outer surface of the cell. the carbohydrate(glyco) portions protrude to the outside of the cell, thus the external surface of the cell has a looseley attached "carbohydrate coat" known as a glcocalyx |
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functions of the glyocalyx(cell coat) |
a] many of the carbohydrate containing compounds are negatively charged and give the cell surface an overall negative charge, b] the glycocalyx of one cell may bind to that of another helping to attach two cells together, c] many of the carbohydrates compounds act as receptor molecules for hormones, d] some of these carbohydrate compounds enter ino important immune reactions |
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contact inhibition |
when two cell membranes tuch the contact between them inhibits their resective reproductive functions |
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nucleus |
1] the nucleus contains the genetic material of the cell(DNA), 2] the DNA of a cell codes for the specific proteins produced by the cell, 3] the proteins have a specific structure which gives it a specific functions, 4] proteins do the work of the cell therefore the nucleus controls functions to the cell |
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pore complexes |
help to regulate large macro molecules and particles that enter into and exit the nucleus through these pores(holes in a wiffle ball) |
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internal nuclear lamina |
consists of a comples nework of protein intermediate fiaments exists on the internal surface of the nuclear membrane, does not cover the pores and helps the nucleus maintain its shape |
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messenger RNA |
transcription (writes down code from DNA) |
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transfer RNA |
translation |
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ribosomal RNA |
partially composed ribosomes |
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nucleolus |
more lightly staining spherical structures in the nucleus, only appear within a nucleus that is not dividing, but reorganize once new cells have formed, contains large amounts of ribosomal ribonucleic acid(RNA) and ribosomal proteins, the area of the cell where ribosomes are assembled |
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ribosomes |
small spherically shaped organelles, may occur singularly in cytoplasm, as groups (polyribosomes) in cytoplasm or attached to the endomembrane system of a cell (membrane bound ribosomes), the ones in the cell synthesize proteins which are used inside the cell, membrane bound ones generally synthesze proteins that will be inserted into te plasa ma membrane or secreted by a cell |
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two subunits of ribosomes |
a large subunit and contains a tunnel, and the small subunit that contains a platform, both structures have imortant functions during protein synthesis |
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