what are the differences between the transport proteins and the carrier proteins in the cell?
926065
Transport is a more general term.\nTransport proteins can be carriers or channels.\nCarriers bind the small molecule that is going to be transported and flip from one side of the membrane to the other. or change their shape so that the molecule binds while being on one side of the membrane and is released on the other.\nChannel proteins, as the name indicates, create tunnels in the membrane through which molecules can pass. The size of the opening and some additionals things make the channels specific to certain molecules. Also the channels can open and close according to the cell's needs.
386583
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.
944110
channel proteins, also called transport protiens\n\nBy the way, tRNA transports amino acids to ribosomes for protein synthesis, and is not protein  but RNA
282844
in mitocondria and chloroplasts there is a series of proteins which 'pass on' electrons to generate energy.  It's called 'electron transport', and is usually discussed in terms of glycolysis and photosynthesis
612940
It would depend on several factors. Small, uncharged molecules can pass through the cell membrane through diffusion. When it is water, it is called osmosis. Diffusion can only occur into the cell when the concentration of the substance is greater outside the cell than within it, and likewise only out of the cell when the concetration is greater inside the cell than outside. This is called the concentration gradient.\n\nWhen the molecule is charged or is large (such as a chlorine ion or a lactose molecule), it requires active transport by carrier proteins. There are also carrier proteins that help to transport against the concentration gradient.\n\n[Edit] \nAfter thinking for a bit, I believe it would be pertinent to include something about the more complex methods of active transport.\n\nThere are two "directions" of the complex forms of active transport: in (endocytosis) and out (exocytosis).\n\nExocytosis is when a vesicle, after being released from the Golgi complex, fuses to the cell membrane, releasing the contents.\n\nEndocytosis is done by three main means: Phagocytosis, Pinocytosis, and Receptor-Mediated Endocytosis.\n\nPhagocytosis is the process of enveloping a large particle, such as how many unicellular organisms "eat" other organisms. The large particle comes in contact with the cell membrane, stimulating the formation of a vesicle. This vesicle then enters the cell and depending on the contents may fuse with a lysosome to help to digest it.\n\nPinocytosis also forms a vesicle, but differs from phagocytosis because it forms a much smaller vesicle.\n\nReceptor-mediated endocytosis is when particles that cannot normally enter the cell bond to receptor proteins embedded in the cell membrane. These proteins then congregate and form a vesicle. \n\nIn all forms of endocytosis and exocytosis, ATP is required for energy.
797991
cells contain the same genetic content. however, our genes express differently to serve different purpose of the cells in different part of our body. some cells needs protein A more, therefore, protein A expressed more. some cells need protein B more, therefore it expressed protein B. nerve cells function is different from liver cell, therefore, there is not necessary to express insulin. but no matter what, the DNA in both cells are the same.
237624
here's a basic answer about stuff we were recently talkin' about in class.... there are intrinsic and extrinsic proteins... also called integral and peripheral proteins... the first guys completely span the membrane bilayer and the second guys just touch the surface of the membrane or only partially go into it.  Proteins can diffuse laterally in the membrane.  They also decrease the fluidity of the membrane and increase its rigidity.  I believe it's oligosaccarides or carbohydrates can also bind to the proteins.  Most of the proteins function though as transporters.  There's so many transporters that that's a new questions in itself and i don't feel like the typing! ;)
98589
Transmembrane proteins form channels through the lipid bilayer.\nThere are different sorts of channels, ion channels for example.\nIn the case of ions, they would not normally be able to cross the membrane, a channel protein (plus associated mechanisms) make it possible.
963665
when sunlight is absorbed by a molecule of chlorophyll electrons in the molecule interact with photons of light and are raised to a higher energy level.  The electrons are passed from one molecule to another in an electron transport chain producing ATP and NADPH.  Incase you dont know ATP is what cells mainly use for energy and NADPH is use as an electron carrier.
880525
flask x- There will be a net influx of water to the blood cells because there a higher concentration of water outside the blood cells, the cell will expand.\nflask y- no net gain or loss of water to the cell. The cells are in equalibrium with the solution. Water will flow in and out, but at an equal rate so there is no net gain. \nflask z- there is a net efflux of water out of the cells  because there is a higher concentration of water in the cell than in the solution. as a result the cell will shrink.
521989
Most obvious difference: peptide hormones usually act extracellularly while steroid hormones usually act intracellularly.\n\nPeptide hormones can't usually cross the cell membrane, so they exert their effects by binding to a cell-surface receptor.  The receptor then has to transmit the signal into the cell through some sort of second messenger system.\n\nSteroid hormones are fat soluble, so they can pass right through the cell membrane.  As a result they usually interact with soluble receptors floating around *inside* the cell.  In many cases, the hormone-receptor complex will act directly on the DNA, to regulate gene transcription--no second messenger required.
900184
some cells to take in more. Cell permiablility.\n\nhttp://www.answers.com/topic/cell-permeability
377572
Substances could move across the cell membrane by either passive or active transport. Passive transport happens with kinetic energy and along a concentration gradient (difference in concentration of a substance).Passive transport includes diffusion, osmosis and facilitated diffusion. Oxygen and carbon dioxide are examples of substances that diffuse.Water will go through by osmosis and glucose is a substance that uses facilitated diffusion.\nActive transport needs energy in the form of ATP and happens against a concentration gradient. Active transport includes endocytosis and exocytosis.It involves the passage in or out of larger molecules.
494099
same:   both have a lipid bi-layer membrane.  Both have Peripheral and integral membrane proteins.\n\nDifference:  single celled normally have cilia or flagella, single celled macrophage whereas multicelled normally don't.  Multicelled handle disease better.
109893
GLUT transporters are found throughout the body, and allow glucose to be transported into a cell through facilitated-diffusion (no energy is required). There are specific locations for each of the GLUT transporters:\n\nGLUT 1: most important in the brain, it constantly takes up glucose, even in low glucose settings, since the brain (for the most part) can only use glucose, whereas all other body tissues can use other energy sources \n\nGLUT 2: liver, pancreas, intestine, kidney; GLUT 2 is responsible for moving glucose, galactose, and fructose from the inside of an intestinal cell into the bloodstream\n\nGLUT 3: neuron, kidney, placenta\n\nGLUT 4: muscle, adipose, heart; increased expression of GLUT 4 when insulin is released, there is hypoxia, or there are dietary changes\n\nGLUT 5: muscle, intestines, spermatozoa; uses FRUCTOSE, rather than glucose, as a substrate
14737
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.
841228
In both cases you have a semi-permeable membrane separating two solutions.\n\nIn the case of osmosis, solutes (which contribute to the phenomenon) cannot pass through the membrane and therefore the solvent has to pass through the membrane in order to equilibrate the osmotic pressure (or better yet the solvent potential) of the two solutions.\n\nIn the case of dialysis you have some solutes which can pass through the mebrane and diffuse from the solution where their concentration is higher to the one where their concentration is lower. Thus dialysis is used when you want to get rid of certain solutes or exchange them with others, while retaining some of the initial solutes in your system. E.g. if you have a protein sample that has too much salt, you can get rid of the salt (or any other small molecule that you don't want in your sample), without losing your protein, by dialysis; you can change the buffering system with dialysis. Of course there are also the medical aspects of dialysis but these have already been described in detail in the other answer.\n\nIn two words, in the case of osmosis you have net movement of solvent whereas in dialysis you have net movement of some solutes from one solution to the other.