what are the structures and functions of the endomembrane system?
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The endomembrane system is the system of internal membranes within eukaryotic cells that divide the cell into functional and structural compartments, or organelles. Prokaryotes do not have an endomembrane system and thus lack most organelles.\n\nThe endomembrane system also provides a transport system, for moving molecules through the interior of the cell, as well as interactive surfaces for lipid and protein synthesis. The membranes that make up the endomembrane system are made of a lipid bilayer, with proteins attached to either side or traversing them.\n\nThe following organelles are part of the endomembrane system:\n\n    * The plasma membrane is a phospholipid bilayer membrane that separates the cell from its environment and regulates the transport of molecules and signals into and out of the cell.\n    * The nuclear envelope is the membrane around the nucleus of the cell.\n    * The endoplasmic reticulum is a synthesis and transport organelle [the endoplasmic reticulum is an extension of the nuclear envelope].\n    * The Golgi apparatus acts as the packaging and delivery system for molecules.\n    * Lysosomes are the "digestive" units of the cell. They utilize enzymes to break down macromolecules and also act as a waste disposal system.\n    * Vacuoles act as storage units in some cells.\n    * Vesicles are small membrane-enclosed transport units that can transfer molecules between different compartments.
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Some of the functions of the primary wall of a plant cell:\n\n    * Structural and mechanical support.\n    * maintain and determine cell shape.\n    * resist internal pressure of cell.\n    * control rate and direction of growth.\n    * ultimately responsible for plant architecture and form.\n    * regulate diffusion of material \n    * carbohydrate storage - walls of seeds may be metabolized.\n    * protect against pathogens, dehydration, and other environmental factors.\n    * cell-cell interactions.
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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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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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Movement of substances across the cell membrane is the function of the 3 types of diffusion.\n\n\nThe generalized cell functions include movement of substances across the cell membrane, cell division to make new cells, and protein synthesis. \n\n\nMovement of substances across the cell membrane \nThe survival of the cell depends on maintaining the difference between extracellular and intracellular material. Mechanisms of movement across the cell membrane include simple diffusion, osmosis, filtration, active transport, endocytosis, and exocytosis. \n\nSimple diffusion is the movement of particles (solutes) from a region of higher solute concentration to a region of lower solute concentration. Osmosis is the diffusion of solvent or water molecules through a selectively permeable membrane. Filtration utilizes pressure to push substances through a membrane. Active transport moves substances against a concentration gradient from a region of lower concentration to a region of higher concentration. It requires a carrier molecule and uses energy. Endocytosis refers to the formation of vesicles to transfer particles and droplets from outside to inside the cell. Secretory vesicles are moved from the inside to the outside of the cell by exocytosis.
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There are two differences the the Endoplasmic Reticulum, which is the most extensive part of the endomembrane system. The rough endoplasmic reticulum (ER) have ribosomes attached to the cytoplasmic surface. The smooth ER lacks ribosomes.\nSmooth ER serves diverse functions in different cells: Its enzymes are involved in phospholipid, steroid, and sex hormone synthesis; carbohydrate metabolism; and detoxification of drugs and poisons.\nSmooth ER also functions in storage and release of calcium ions during muscle contraction.\nProteins intended for secretion are manufactured by membrane-bound ribosomes and then threaded into the lumen of the rough ER, where they fold into their native conformation. Many are covalently bonded to small carbohydrates to form glycoproteins. Secretory proteins are transported from the rough ER in membrane-bound transport vesicles.\nRough ER manufactures membranes for the cell. Enzymes built into the membrane assemble phosolipids, and membrane proteins formed on bound ribosomes are inserted into the ER membrane. Transport vesicles transfer ER membrane to other parts of the endomembrane system.
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The endocrine system is a collection of glands and organs that produce and regulate hormones in the bloodstream to control many functions of the body. This system overlaps with the nervous and exocrine system, and its responsibilities include metabolism, growth, and sexual development. Most animals with advanced physiology, such as vertebrates and crustaceans, house an endocrine system.
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The Plasma Membrane (PM) is very important and highly regulated part of the cell. Mainly composed of phospholipids (hydrophobic tails and hydrophilic heads) that are double layered. Also, many other components encompass the PM such as cholesterol (to keep the PM fluid), glycoproteins, and other proteins.\n\nThe PM serves as a major part of the cell's communication pathway. Serves as a barrier for communication with other cells, allows other molecules to anchor on the membrane, allows other cells to attach via cytoskeletal components, makes anchor junctions etc...with other cells.\n\nThink of the PM as the doors and windows of a home (the cell). It is quite important for these parts to be regulated. The doors allows certain people to leave to the home to interact with others, it allows people or items to come inside the home to interact. The windows allow for fresh air to come inside the home which can be regarded as quite essential for survival.
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The primary function of the uterus is in reproduction; the conduit for sperm transport, and the site for implantation of fertilized ova, placentation,  growth and development of the fetus, and parturition (labor and delivery).
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They are involved in signal transduction mostly.  They are involved at the cell membrane.  They phosphorylate Rho GTPases.
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cell wall - a thick, rigid membrane that surrounds a plant cell. This layer of cellulose fiber gives the cell most of its support and structure. The cell wall also bonds with other cell walls to form the structure of the plant.\n\nYou will find the rest here --> http://www.enchantedlearning.com/subjects/plants/cell/
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You best resource is the internet. Since you are the only on who knows what your level of understanding is, only you can choose from the multitude of sources.  Please choose the one that comes closest to what you need:\nhttp://www.google.com/search?num=100&hl=en&lr=lang_en&q=cell+membrane+loose+stability+%2B+oxygen+depletion&btnG=Search\nhttp://search.yahoo.com/search?fr=ytff1-&p=cell%20membrane%20loose%20stability%20%2B%20oxygen%20depletion&ei=UTF-8
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I'd have to say water (controls concentration gradients) and proteins (which form channels for things that can't cross the membrane by themselves).
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1. Energy production and storage\n2. Structure.\n3. Supply carbon for synthesis\n4. Cell identification.
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Info on the Endocrine system:
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Cytoplasm is the area within the cell inside the plasma membrane (the membrane separate the cell to others) and outside the nucleus (the region contaning genetic materials DNA). Cytoplasm contains many internal organelles (internal structures) that are necessary for cell's functions.\nINternal organelles: Ribosome (needed to make proteins), Golgi complex, lysosomes (digest defective materials in cells, only found in animal cells),Endoplastic Reticulum (2 types: rough with ribosome attached and smooth without ribosome), central vacuole (store H2O, toxins, pigments, waste), Mitochondria (use to make energy for cell, mostly from glucose), chloroplast (needed for photosynthesis in plant cells only),cytoskeleton (connect organelles to each other and membrane, control cell movement, cilia and flagella (cell movements inside an organism).
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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.