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Aquaporins are protein molecules embedded in the phospholipid bilayer (cell membrane ) of some cells. They transport water across the cell membrane.
Wiki User
∙ 12y ago
Wiki User
∙ 8y agoAn aquaporin is any of a class of proteins which form pores in the membrane of biological cells.
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Transport protein that provides a tubelike opening in the plasma membrane through which particles can diffuse?
Channel Protein.
Aquaporins are believed to be present in red blood cells and kidney tubules but very few other cells in the body?
False
How do molecules diffuse?
Movement of solutes across a lipid bilayer plasma membrane can occur in many ways:1. Osmosis: diffusion of water across membranes to balance solute concentrations.- No energy req- Water passes through membrane via aquaporins, pores in the membrane permeable only to water.2. Simple diffusion: diffusion of only small, hydrophobic (nonpolar) molecules across a membrane down their concentration gradient.- No energy req- Only moves small nonpolar molecules down their concentration gradient3. Facilitated diffusion (passive transport): uses transmembrane protein transporters (channels and carriers) to move polar molecules (ions) across a membrane- No energy required- Channel proteins: Allow for rapid diffusion of specific ions down their concentration gradient- Can be activated by:- Voltage- Ligand- Mechanical force- Carrier proteins: Allow for selective diffusion of specific ions down their concentration gradient.- Uniport carriers: only transport one specific ion down its concentration gradient- Symport carriers: move two different types of ions in the same direction.- Antiport carriers: moves two different ions in opposite directions-Can use the energy created moving one molecule down its concentration gradient to move an ion against its concentration gradient- Carrier proteins exhibit saturation, competition, and specificity.4. Active transport: transport of solutes across a membrane against their concentration gradient.- ATP req- Uses carrier proteins- Leads to creation of potential energy stored in electrochemical gradients
What channel proteins allow water to pass across the membrane?
Aquaporins
Water may move through membrane pores constructed by transmembrane proteins called?
aquaporins
What is helped by aquaporins?
osmosis
Does transporting aquaporins proteins require ATP?
no
What channels does water cross plasma membranes?
Aquaporins.
Are aquaporins involved in osmosis or facilitated diffusion?
facilitated diffusion
What substance is transported by aquaporins?
The correct answer is water. Aquaporins are a newly discovered class of transport proteins that transport water in cells with very high water permeability needs. - Vance Austin Neely
How does water reabsorption in kidneys occur?
by osmosis through tubular aquaporins
What are membrane proteins that create a passageway across cell membranes?
Aquaporins
Why does water pass quickly through cell?
it moves through aquaporins in the membrane.
What condition might result from an excess of aquaporins?
fluid retention in pregnant woman
What is the role of aquaporins in a cell membrane?
Aquaporins are protein molecules embedded in the phospholipid bilayer of some cells. They transport water across the cell membrane. A certain amount of water can cross the phospholipid bilayer of the membrane, but aquaporins considerably increase the rate of passage of water. One type of cell in which aquaporins are found is in the epithelium of the human kidney, in the distal and collecting tubules. The antidiuretic hormone (ADH) stimulates epithelial cells to incorporate aquaporins into their membranes, increasing the uptake of water from the tubule into the cells, and therefore increasing the reabsorption of water into the body. Aquaporins are also important in plant cells, facilitating the symplastic movement of water through the plant, i.e. the movement of water from cell to cell via cytoplasm.
