What s going on with water ion channel proteins?

To correct it, there are no water ions.

The transmembrane channel of water molecules, which is hydroporin.

Other names: Aquaporins.

Definition: A highly conserved family of membrane transporting proteins in which proteins form homotetramers and each subunit is crossed multiple times to form a transmembrane channel, allowing water and hydrophilic small molecules (e.g., glycerol) to cross the biofilm.

There are some proteins present in the protoplasmic membrane and vacuolar membrane that play the role of selective aquaporins and these proteins are known as aquaporins or are called aquaporins. Aquaporins belong to a family of integral membrane proteins. Hydroporins constitute selective water channels.

They allow water to pass freely, and some aquaporins also allow small molecules of non-electrolytes to pass through, but they repel ions, such as those found in corn, which do not allow glycerol, choline, urea, and amino acids to pass through, and although aquaporins allow water to pass through, they do not act as pumps. The driving force of this water movement is water pressure or osmotic pressure in the plant body, and hydroporins are found in vacuolar membranes (e.g., in maize) and in Arabidopsis, as well as in protoplasmic membranes, e.g., in tobacco, Arabidopsis.

Water is not an ion, it is a molecule, only water molecule channel protein, figuratively speaking, just like a hollow water pipe, which can allow water molecules to pass freely, and the rate of its passage is much greater than the rate of free diffusion of water molecules, so it is called "water channel".

Aquaporins (AQPs) are important factors affecting water NA metabolism.

Aquaporin, also known as aquaporin, is a protein located on the cell membrane (inner membrane protein) that forms "pores" on the cell membrane and controls the flow of water in and out of the cell, just like a "pump of the cell".

The water channel was discovered by Peter Agre, an American scientist at the Johns Hopkins University School of MedicineHe was awarded the 2003 Nobel Prize in Chemistry with Roderick McKinnon of the Howard Hughes Medical Research Center at Rockefeller University, who confirmed the structure of potassium channels by X-ray crystallography.

When the water molecules pass through the aquaporin, they will form a single longitudinal column and enter the curved and narrow channel, and the dipole force and polarity inside will help the water molecules rotate and pass through the narrow channel at an appropriate angle, so the protein configuration of the aquaporin is the reason why only the water molecules can pass through.

The water channel was discovered by Peter Agre, an American scientist at the Johns Hopkins University School of MedicineOrganized by the education network.

He and Rockefeller University's aquaporin, also known as aquaporin, is a protein located on the cell membrane (intrinsic membrane protein) that forms a "pore" on the cell membrane to control the flow of water in and out of the cell, just like a "cell pump".

The water channel was discovered by Peter Agre, an American scientist at the Johns Hopkins University School of MedicineHe was awarded the 2003 Nobel Prize in Chemistry with Roderick McKinnon of the Howard Hughes Medical Research Center at Rockefeller University, who confirmed the structure of potassium channels by X-ray crystallography.

AQP is a group of cell membrane transporters that make up water channels and are related to water permeability, which are widely found in animals, plants and microorganisms. At present, there are 8 AQPs (AQP0, AQP1, AQP2, AQP3, AQP4, AQP5, AQP6, AQP7) monitored in mammalian tissues, collectively known as "aquaporins (AQPs)", and each AQP has its own specific tissue distribution.

Different AQPs have different roles and regulatory mechanisms in the process of water absorption and secretion in the kidney and other organs. The transport of water through the water channel is different from simple diffusion, and its permeability is much greater than that of diffusion.

For example, the cell membrane is the wall, the gap between the membrane molecules is the crack in the wall, and the water channel is the water pipe that passes through the wall. So I think you can get a good idea of how efficient they are. The amount of water needed for cellular metabolic activities is considerable, and how can a crack in the wall be enough?

So most of the water still has to be transported by water channels.

The discovery of aquaporins is extraordinary; Because water channels are key to the movement of water in and out of cells, many physiological processes involve the flow of body fluids, such as sweating, urination, inflammation, redness, and tearing. The function of aquaporins allows us to concentrate urine on hot summer days without dehydration, and it also allows us to release water stored in adipose tissue when we are hungry.

Coming (water porin) is an intrinsic egg white that exists on the cell membrane source, and the egg white is a channel that controls the entry and exit of water molecules, and.

DAO can only transport water, and no other inorganic ions and macromolecules can pass through, that is to say, it is a specific channel for water, and when water needs to pass, the protein will rotate the water molecules, and finally enter the cell at the best angle. As long as you understand that carrier proteins and aquaporins are essentially proteins, and the former plays the role of transport (car), and the latter plays the role of channel (gate), there will be no confusion.

The mode of transport of water should be both free and assisted. It should be said that in most cases (between cells or into cells) water is transported by free diffusion, without the assistance of ATP and carrier, and when water enters the cell through hydroporin, hydroporin acts as a carrier function, and at this time it needs a carrier, does not consume ATP, and belongs to free diffusion.

Channel proteins are proteins similar to doors, and when they move, they are equivalent to opening the door, exposing the channel, and the water will enter, which is suitable for a large amount of water intake.

As for ion channels, the reason is that these channels are electrically charged, and not everything can pass through, only if they are smaller than their diameter, and the charge is opposite to that of the channel.

Water channels (aquaporins, aquaporins), are the main way water moves in and out of cells.

Recently, the presence of efficient water transmembrane transport channels within the present plasma membrane and vacuolar membranes - water channels, on the one hand, the transmission channels of AQP water, and on the other hand, the channels of CO2, glycerol and other metal ions and other small molecules, it may be associated with the water cycle, transpiration rate and photosynthetic efficiency of plants. In the presence of aquatropins, identification and detection of aquaporins, most of which serve as experimental functions of mercuric chloride, are specific inhibitors of aquaporins. However, some aquaporins are insensitive to mercury, and this is not the only standard presence of mercury-sensitive aquaporins as an identifier.

First of all, I want to know that the book ** says that water in and out of the cell is free to diffuse, this statement is not rigorous, and many of the answers in the book are not rigorous. The mechanism by which water moves in and out of cells is complex, and can be summarized as follows:

In the presence of aquaporins, water enters and exits the cell through aquaporins (similar to assisted diffusion), and in the absence of aquaporins, water enters and exits the cell by free diffusion.

Therefore, in the high school question, it is not right to write about the way water enters and exits the cell, and it is not right to write about free diffusion

Ion channels refer to carrier proteins that transport ions in and out of cells, and the sodium-potassium pump is an ion channel that specializes in transporting sodium-potassium ions by making the concentration of sodium ions outside the cell higher than that inside the cell.

Many statements in high school books are not rigorous, so don't do the college entrance examination questions too deeply, according to our teacher's statement, you can do it if you make a mistake, as long as you know what the test center is, answer it according to the test center, otherwise you think the college entrance examination questions are not rigorous, you also go to question the teacher?What's more, many theories themselves are also subject to verification and are controversial in academic circles.

The above is purely hand-played.

For a long time, it was thought that water molecules from inside and outside the cell penetrate the lipid bilayer membrane by simple diffusion. It was later found that some cells were highly permeable to water in a hypotonic solution, which is difficult to explain by simple diffusion. For example, after moving red blood cells into a hypotonic solution, they quickly absorb water and swell and dissolve blood, while the oocytes of aquatic animals do not swell in the hypotonic solution.

Therefore, it has been speculated that there is some special mechanism for the transmembrane transport of water in addition to simple diffusion, and the concept of water channels has been proposed. In this case, water flows in and out of the cells for assisted diffusion.

But what do you have doubts about the ion channels and sodium-potassium pumps you are asking?

Hope it helps.

Aquaporins are proteins that control the flow of water in and out. Mainly affected by the concentration (water potential) inside and outside the membrane, it does not need to consume energy to transport water, and the way is to assist diffusion.

However, this part is not covered in high school, so it is generally believed that method B is a water molecule.

Ways in and out. c In order to assist diffusion (facilitated diffusion), it requires a carrier and does not require energy, and its transport rate is determined by the number of carriers and the difference in concentration between the inside and outside the membrane, like the absorption of glucose by red blood cells.

The way to do that is to assist in proliferation. A is an ion channel (active transport) that requires a carrier and energy, but no sugar (non-glycoprotein).

C is an active transport mediated by glycoproteins, which recognize specific substances (e.g., hormones, antigens) and absorb them.

At present, there are at least 11 such proteins found in human cells, named aquaporin (AQP), all of which have the property of selectively allowing water molecules to pass through. Thirty-five such channels have been found in the experimental plant Arabidopsis thaliana.

Regulation of the activity of water channels may have the following pathways: enhanced activity of AQP through phosphorylation; Alteration of the content of AQP on the membrane through membrane transport, such as vasopressin (antidiuretic hormone) regulates the water permeability of renal distal convoluted tubules and collecting tubule epithelial cells; Promotes AQP synthesis by regulating gene expression.

It is the water potential of the cell that determines the water in or out of the cell.

Water passes through the membrane through two mechanisms. One is through diffusion of the lipid bilayer. Because the lipid bilayer is hydrophobic, there is not no space in it in which water molecules can form an ice-like structure through hydrogen bonding, thus crossing the membrane.

Agre et al. (1988) isolated and purified Rh polypeptides from erythrocyte membranes and discovered a 28 kd hydrophobic transmembrane protein called channel-forming inte—gral membrane protein (ChIP28), which was cloned in 1991 (Verkman, 2003). However, the function of this protein was not known at that time, and when the function was identified, the ILP28 mDNA was injected into the oocytes of Xenopus laevis laevis and found to expand rapidly in the hypotonic solution and rupture within 5 minutes. In order to further determine its function, it was constructed in the protein phospholipid body, and it was confirmed that it was an aquaporin through the determination of activation energy and permeability coefficient and subsequent studies of inhibitor sensitivity.

Since then, it has been determined that there is a specific channel protein on the cell membrane that transports water, and ChIP28 has been called Aquaporinl (AQPL).

Aquaporin, also known as aquaporin, is a protein located on the cell membrane (inner membrane protein) that forms "pores" on the cell membrane and controls the flow of water in and out of the cell. The water channel was discovered by Peter Agre, an American scientist at the Johns Hopkins University School of Medicine, who was awarded the 2003 Nobel Prize in Chemistry along with Roderick McKinnon of the Howard Hughes Medical Research Center at Rockefeller University, who confirmed the structure of potassium channels by X-ray crystallography. When the water molecules pass through the aquaporin, they form a single longitudinal column and enter the curved and narrow channel, and the dipole force and polarity of the inner fissure will help the water molecules rotate and pass through the narrow channel at an appropriate angle, so the protein configuration of the aquaporin is the reason why only the water molecules can pass through.