where are cell membrane proteins produced and how do they get to the cell membrane?
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Cell Membrane proteins are made inside the cell and inserted into invaginations of the cell membrane called Endoplasmic Reticulum.  At least that's how it works in Eukaryotes (everything from humans and plants to Amoebae).  Prokaryotes (bacteria) must do something similar, but their internal structure is different.\n\nEukaryotes have long stretches of endoplasmic reticilum inside them (but outside the nucleus).  ER is essentially the cell membrane, in long deep convoluted invaginations; it's continuous with the cell membrane but all-but pinched off at the cell surface.\n\nProteins are manufactured by ribosomes (it's a complicated mechanism, but involves the ribosomes anyway) which read the information of mRNA to string amino acids together to make protein.  If the nascent protein chain has the right sequences, its inserted into the ER membrane as it's growing.  As it grows, it pokes through the ER  and out the other side: the "head" of the protein sticks out, while the "tail" is still growing on the inside of the cell.  If the protein has a particular control sequence, called a "stop transfer" sequence, the mechanisms pushing it through the ER stop, and it remains embedded in the ER membrane.  If it doesn't have this sequence, it gets pushed right on through.\n\nWhen the protein is finished, a small pocket of the ER membrane pinches off to form a bubble or "vessicle" inside the cell.  The vessicle membrane will have the new protein embedded in it, with the head of the protein inside the vessicle and the tail sticking out.  If the protein was pushed all the way through, it will be completely inside the vessicle.\n\nThe vessicle is moved to the cell surface by microfibers (a kind of protein called actin that forms fibers that can slide over each other.  It's also found in muscle).  The vessicle fuses with the cell surface and opens up; the "inside" of the vessicle is now the outside of the cell.  The head of the protein, that was on the inside of the vessicle, is now on the outside of the cell, and the tail of the protein is still on the inside, and the cell membrane protein is ready to go.\n\nIf the protein went all the way through the ER, and wound up completely inside the vessicle, then it is secreted (released from, as in a secretion) from the cell when the vessicle fuses with the cell membrane.  You can turn a cell membrane protein into a secretatory protein by removing the "stop transfer" sequence of amino acids from the protein.  This is believed to happen sometimes, for example, when an antibody molecule (a protein) that is embedded in the cell membrane triggers the cell to begin to secrete the same antibody molecule into the blood stream: if something binds to the embedded antibody, the cell begins to manufacture the same molecule but without the stop-transfer sequence, so the cell now secretes antibodies.
778955
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.
780679
1 ribosomes\n2 stimuli\n3 enzyme\n4 cytoplasm
277111
From respiration: Here, glucose molecules in the cell are broken down; the molecules have strong bond between them and so when they are broken, energy is provided(by mitochondria) and when new molecules are formed, energy is released, which the cell uses for various processes.\n\nFrom protein synthesis: It occurs on the ribosomes in the cytoplasm, and aminoacids are combined to form proteins and this releases energy.\n\nFrom ATP(adenosine tri-phosphate): The ATP molecule is a packet of energy which stores the energy released during any process going on in the cell and then releases the energy as and when required by the cell.
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DNA goes to mRNA\n\nthe mRNA has a signal sequence on the 5' end which directs it to the Ribosome and indicates whether it will be inserted into the Endoplasmic Reticulum(ER) while it is being translated.  In this case it is inserted into the ER.  As it is inserted it is folded into it's 3-D conformation.  Pending on whether parts are inserted into the membrane of the ER or not it will be determined if this Plasma Membrane(PM) protein is secreted or is stuck to the membrane.  After this you get the addition of the "glyco" part of the protein through numerous transferases and other molecules inside the ER.  This only happens inside the ER, as to why the former steps were necessary.  Then the protein is transfered via a vesicle to the Golgi Apparatus where further post-translational modifications take place.  At this point the protein is ready to go to the plasma membrane as a glycoprotein.  The protein needs no signal to get there however as the pathway from the Golgi to the PM is the "default" pathway and any unmarked(so to say) vesicle will find it's way to the Plasma Membrane.  And that's that.
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With facilitated diffusion, proteins are needed to make an opening in the cell membrane.  However, once this opening is there, particles diffuse from the side which has the higher concentration to the side with the lower concentration, just like regular diffusion.  (The difference in concentrations is called the concentration gradient.)\n\nIn active transport, much more effort is needed to make it happen.  For example, in phagocytosis, the cell wall actually engulfs a particle and brings it inside the cell.  The difference is between the transport being facilitated or being forced.
810035
There are two classes of molecules that make up the cell membrane. These are  lipids and proteins.\nLipids constitute the two layers called bilyer. A lipid has two ends. One is called head and the other tail.The former is hydrophilic and the latter is hydrophobic.The lipid molecules are arrayed in such a manner that the tails face each other while the heads are away.The heads are in contact with cytoplasm on the one hand and exterior on the other.The the heads interact electrostatically with proteins. Some proteins are buried in the bilayer, and some even project beyond the bilayer on both the surfaces. Carbohydrates are over-layered, that is, on the outer side of this complex. Some lipids are phophorylated. Cholesterol is also present in some quantity in the membrane.
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Protein along with lipids form a lipoproteinous wall that surrounds the cell which is called plasma-membrane.for details got to below given link:\nhttp://en.wikipedia.org/wiki/Plasma_membrane
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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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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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Okay this is a bit of a complicated question, but i'll do my best, in short these are really very different things.\n\nFirst cell membranes are found in all cells (animal, plant, fungi etc.) they are made up of lipids, generally as a bilayer.  take the membrane from around the outside of a eukaryotic cell, its formed from phospolipids - these molecules have a hydrophilic head [ie will disolve in water/ has a charge] (the phosphate bit) and a hydrophobic tail (the lipid (fat) bit). The hydrophobic bits stick together and the hydrophilic bits are open to the solution on each side (search "lipid bilayer" with yahoo! Images if you want a diagram:-) ).  The outer cell membrane is forming a barrier between the inside and outside of the cell, alowing the cell to control the movment of molecules into and out of itself.  There are a lot of other membranes in the cell apart from the outher cell membrane, the endoplasmic reticulum for example is basicly made up of membrane.\n\nThe cell wall on the other hand isn't present in all cells (we humans (along with all other animals) don't get one). The cell wall is present on the extracellular side of the outer cell membrane.  it is hard and ridgid (unlike the membrane that is fluid) it is made up of lond polymers, and serves to protect the cell.  Plant cell walls are made up of mainly cellulose (in fact when you look at a peice of wood all you are really seeing is the leftover cell walls, and the rest of the cell has long gone).  Fungi also have cell walls but this time not made of cellulose but instead made of chitin, the cell wall still serves the same role however.\n\nIn short the membrane lets the cell control what goes in and out,  and the cell wall provides rigidity.  Membranes are made of lipids (fats) and cell walls of long polemers like chitin and cellulose.\n\nI hope this helps to answer your question, and look for some diagrams - it will make it a lot easier.
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I know there are some proteins produced by prokaryotes and eukaryotes that lack a typical leader peptide sequence; for example lacking a hydrophobic leader peptide. Some of these proteins are exported to the membrane by a substrate specific ATP-driven membrane translocater. Used to be called ABC-transporters because they could bind and hydrolize ATP. I think T-cell presentation is associated with a system like this where ABC-transporters transport endogenous antigenic peptides to the ER where\nthey bind to the MHC: peptide receptor complex before being\ntransported to the cell surface. I know S. cerevisiae, MATa haploid cells, release a 12-residue posttranslationally modified lipopeptide that binds via a farnesyl\nmoiety attached via a thioether linkage to the C-terminal residue. So, basically I would suggest looking at a possible ABC-transporter or a lipopeptide. There might be other options but they escape me at the moment.
464037
The power house of a cell is the mitochondria.  ATP is produced through cellular respiration, which starts out with glycolysis, and goes into the Kreb cycle, ending with the electron transport chain.  Glycolysis requires an input of 2 ATP to obtain a net product of 4 ATP.  The end product is acetyl CoA, which enters the Kreb cycle.  The Kreb cycle takes place in the matrix of the mitochondria.  The products of the Kreb cycle are 2 GTP, NADH, FADH2, water (H2O), and carbon dioxide(CO2).  NADH from the Kreb cycle then enters the electron transport chain (ETC).  At the end of ETC, you gain 34 ATP.  The result of the entire process results in a net product of 36 to 38 ATP.
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Their function in the body. For instance, cells that require a lot of communication between them and the outside have a lot of transmembrane proteins that others that are more "isolated".
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Abstract. \n...membranes, microvilli, and membrane projections, and act as crosslinkers between the actin cytoskeleton and proteins of the cell surface...\nhttp://147.52.72.117/IJO/2002/volume21/number5/935-940.pdf \n\n \nforthcoming meetings\nAim: to learn techniques commonly used to analyse signal transduction ... and cell adhesion (cytoskeleton, cell adhesion proteins, extracellular\nhttp://www.usgeb.ch/skmb2005.html \n\n \nBTO\n...and function of proteins, methods of ... Cytoskeleton and cell motility. ... Describe and use structure determination techniques to analyse\nhttp://www.bto.ed.ac.uk/courses/year1/index0506.phtml \n\n \nRandall Division o f Cell and Molecular Biophysics\n...actin cytoskeleton during migration. I use a number of different advanced imaging techniques to analyse ... analysis of interacting proteins by\nhttp://www.kcl.ac.uk/depsta/biomedical/randall/mparsons.html \n\n \nGlossaire (ULg)\nAnkyrins. A family of membrane-associated proteins responsible for the attachment of the cytoskeleton. Note: membrane proteins \nhttp://www.ebm.lib.ulg.ac.be/prostate/gloss.htm \n\n \nThe role of the axolemma in the initiation of traumatically induced...\n...proteins. Transmembrane proteins such ... matrix to the cytoskeleton via the ... Biophysical investigations have used novel techniques to\nhttp://www.jnnp.com/cgi/content/full/64/3/285 \n\n \nThe tiniest parts of \n...are as dispart as the techniques and ... natural science, is to analyse the ... energy or information, signal transducers, cytoskeleton...\nhttp://www.uni-leipzig.de/~philos/psarros/preprints/the_tiniest_parts_of.html \n\n \nGenome Biology | Full text | Analysis and functional classification\n...as well as the development of new techniques for ... genes encoding cytoskeleton proteins (such as myosin, actin, UNC-87, troponin T) and\nhttp://genomebiology.com/2003/4/4/R26 \n\n \nStudy Abroad 2004 INTRODUCTION 2 Deakin University's unique Study \nUnit Handbook GUIDE TO UNIT DESCRIPTIONS ACD206/306 Dance Production and Analysis Second semester, 1 credit point Prerequisite ACD203 or Level One \nhttp://www.deakin.edu.au/international/Documents/Brochures/SAHandbook.pdf \n\n \nAdrian Harwood\n...genetic, biochemical and cell biological techniques to analyse the ... has both a cytoskeleton and a network ... SH2 domain proteins,\nhttp://www.ucl.ac.uk/LMCB/pages/harwood.html
415464
Viruses need to be inside of a  host cell (human, bacteria, plant etc.) to reproduce. So to get inside the host they have surface proteins (sticking out of a lipid bilayer-just like most mammalian cells) that are able to trick the host cell into letting it inside, that's where it does the damage to the host. ---To simplify the virus needs to have a Protein Coating that is similar to the Protein Receptors on its host cell in order to infect it.---
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Membrane proteins.\n\nSome membrane proteins act as channel proteins that allow for passive diffusion of solutes across the membrane.\n\nOthers are transport proteins that take part actively (require energy) in transport across the membrane. Some transport proteins may be gated.