i need definitions about cell membranes?
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CELL MEMBRANE IS THE BOUNDARY BETWEEN IT'S CELL AND IT ENVIRONMENT
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Interphase\n\nhttp://www.cellsalive.com/cell_cycle.htm
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All the answers are here --> http://en.wikipedia.org/wiki/Cell_%28biology%29\n(and in your book)
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nucleus - \nOne or more per cell \nSpherical shape \nDenser than surrounding cytoplasm\n\nmembrane - \n\nNUCLEAR membrane - Surrounds nucleus\n- Composed of two layers\n- Numerous openings for nuclear traffic\n\nPlasma membrane\n\n- Outer membrane of cell that controls cellular traffic\n- Contains proteins (left, gray) that span through the membrane and allow passage of materials\n- Proteins are surrounded by a phospholipid bi-layer.\n\ncell wall - \n- Most commonly found in plant cells\n- Controls turgity\n\nvacuole - \n\n- Membrane-bound sacs for storage, digestion, and waste removal\n- Contains water solution\n- Contractile vacuoles for water removal (in unicellular organisms)\n\ncytoplasm - \nCollective term for cytosol and organelles contained within \nColloidal suspension \nCytosol mainly composed of water with free-floating molecules \nViscosity constantly changes\n\n\n\n\nEDIT:  Nucleus' job is to be the control center of the cell and also to store the DNA info.
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The cell membrane is made up of a phospholipid bilayer, with a polar phophate head and a nonpolar lipid tail. The polar head is hydrophilic, the nonpolar tail is hydrophobic. A fat molecule will face toward the nonpolar, hydrophobic tail.
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All are found in A) the cell membrane. \n\nThe cell membrane is made up of a phospholipid bi-layer that is dotted with proteins, markers, ion channels and receptors (which are also protein based).  The receptors/channels/markers all either identify the cell or allow things to pass in/out of it,  or allow things to attatch.  If they were anywhere else, it wouldn't make sense.\n\nSo your answer is A
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All cells are semipermeable and depending on what passes into the cell, determines how the membrane responds to each substance. Glucose moves across the membrane, as do sodium and potassium.
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The cell membrane is a lipid bilayer made from phospholipids.  As a lipid, it is permeable to other lipids (e.g. steroid hormones) but not to polar molecules (e.g. potassium or glucose).  Polar molecules require various types of membrane proteins (e.g. potassium channels) or endocytosis (glucose) for absorption into the cell.  \n\nHope this is helpful for you.  Best wishes and good luck.
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D - definitely all of these:\n\nA - TRUE: liposomes are shaped like a donut, in which the membrane is a lipid bilayer\nB - TRUE: by definition, liposomes contain an aqueous core; if the core is empty, they are called micelles\nC - TRUE: The heads are hydrophilic, the tails are hydrophobic.
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The cell membrane regulates what comes in and what leaves the cell....it kind of acts like a filter!
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The cytoplasm containing the other cell parts.
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In cell biology, a vesicle is a relatively small and enclosed compartment, separated from the cytosol by at least one lipid bilayer. If they have only one lipid bilayer, they are called unilamellar vesicles; otherwise they are called multilamellar. Vesicles store, transport, or digest cellular products and wastes.\n\nThis biomembrane enclosing the vesicle is the same as that of the outer cellular membrane. Then, because of the separation, the intravesicular environment can be made to be different from the cytosolic environment. Vesicles are a basic tool of the cell for organizing metabolism, transport, enzyme storage, as well as being chemical reaction chambers. Many vesicles are made in the Golgi apparatus, but also in the endoplasmic reticulum, or are made from parts of the plasma membrane.\n\nMore at http://en.wikipedia.org/wiki/Vesicle_%28biology%29
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Cell walls surround the cell outside of the plasma membrane.  When water flows into the cell by osmosis, the cell swells until its membrane builds up pressure against the cell wall.  The cell wall prevents the cell from swelling and bursting in a hypotonic solution.
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Lysosome\nFlagella\nCentriole\nCentrifuge\nMyofibrils
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all cells are composed of atoms in the nucleous.  All cells have a cell wall/cell membrane, cytoplasm/protoplasm.\ngolgi bodies\n\n\nYou can't have a cell without these things
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A plasma membrane or cell membrane or plasmalemma structured bilayer of phospholipid and protein molecules.\nThe basic composition and structure of the plasma membrane is the same as that of the membranes that surround organelles and other subcellular compartments. The foundation is a phospholipid bilayer, and the membrane as a whole is often described as a fluid mosaic – a two-dimensional fluid of freely diffusing lipids, dotted or embedded with proteins, which may function as channels or transporters across the membrane, or as receptors. \n\n"The model was first proposed by S.J. Singer (1971) as a lipid protein model and extended to include the fluid character in a publication with G.L. Nicolson in "Science" (1972)."
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animal cell\ncell membrane - controls what moves in and out of the cell\ncytoplasm - the jelly like substance the organelles sit in\nnucleus - controls the actions of the cell\nlysosome - structure with digestive enzymes that break down wornout cells and debris\nvacuole - stores food, water, and wastes\nnuclear membrane/envelope - controls what moves in and out of the nucleus\nribosomes - synthesize and produce proteins\nendoplasmic reticulum - synthesizes materials and transports them to other parts of the cell\ngolgi body - packages and modifies materials and sends them to other cells\nchromatin - genetic information that tells the what to do\nnucleolus - knot of chromatin that produces ribosomes\nmitochondria - produces energy for cell\n\nPlant cell ( added on )\ncell wall - a rigid layer that gives shape and supports the cell\nchloroplasts - absorbs sunlight needed for photosynthesis