Concept explainers
Introduction: Aquaporins or water channels are the proteins that help in the movement of water across the membrane. They are integral membrane proteins that form pores in the membrane to allow the transfer of water and sometimes small solutes.
Answer to Problem 1TY
Correct answer: Aquaporins are the protein channels that allow the transfer of water across the plasma membrane. Hence, the correct answer is option c.
Explanation of Solution
Reason for correct answer:
Aquaporins are a part of major intrinsic proteins that result in the pore formation. This allow the exchange of water molecules, and in some cases, small solute particles across the plasma membrane.
Option c. is given as “a protein channel in plasma membranes that facilitates the diffusion of water”.
The intrinsic proteins that cause the exchange of water molecules across the membrane are called aquaporins. Hence, the correct answer is option c.
Reasons for the incorrect answer:
Option a. is given as, “a channel protein that allows the influx of K+ into cells, causing water to flow in between the phospholipids of the plasma membrane”.
The aquaporins only allow the transfer of water molecules from extracellular fluid to the cytoplasm and not ions. Hence, option a. is incorrect.
Option b. is given as, “a type of blue-colored pore in the epidermal surfaces of plants”.
The aquaporins are not blue colored and are present in the plasma membrane of the cells for the transport of water. Hence, option b. is incorrect.
Option d. is given as, “a transport protein, or transporter, in plasma membranes that use protons to co-transport water”.
Aquaporins are the primary channels for the transport of water, some small neutral solutes and carbon dioxide through the plant cell membrane. They transfer the water molecules based on the concentration gradient. Hence, option d. is incorrect.
Option e. is given as, “none of the above”.
The aquaporins serve as protein channels that are hydrophobic and allow the transfer of water molecules. Hence, option e. is incorrect.
Hence, the options a., b., d., and e. are incorrect.
Aquaporins are present on the plasma membrane of the plant, animal, and bacterial cells. These protein channels serve as the key transport route for the water molecules. They are hydrophobic and can also transfer some neutral solutes and carbon dioxide across the plasma membrane.
Want to see more full solutions like this?
Chapter 39 Solutions
BIOLOGY-TEXT
- The movement of water across the plasma membrane of a cell is facilitated bya. aquaporins.b. substrate-mediated endocytosis.c. receptor-mediated diffusion.d. channel proteins.e. Both a and d are correctarrow_forward(2) a. Mineral salt is essential for growth of a plant. The process responsible for absorption of mineral salt is: a. Mass flow b. Diffusion Active transport C. d. Osmosis b. The reason for my answer is because : a. Absorption occurs due to concentration gradient b. Absorption occurs with the help of energy opposing to diffusion C. Movement as a bulk due to pressure changes d. Absorption through permeable membranesarrow_forwardWhich of the following describes how osmosis occurs across a cell membrane/ A. Solutes move from an area of high water concentration to an area of low water concentration. B. Water moves from an area of low solute concentration to an area of high solute concentration. C. Both water and solutes move across the cell membrane from an area of high concentration to an area of low concentration. D. Solutes move from an area of low solute concentration to an area of high solute concentration. E. Water moves from an area of high solute concentration to an area of low solute concentration.arrow_forward
- (1) a. The process responsible for absorption of water by root hair of plants is : a. Osmosis b. Active transport C. Diffusion b. The reason for my answer is because : a. Concentration of cell sap is lower than that of soil water b. Concentration of cell sap is higher than that of soil water C. Movement of water molecules spending energy, opposing to diffusion d. Water concentration of soil particles is lower than that of root hair cellsarrow_forwardAn aquaporin isa. a channel protein that allows the influx of K+ into cells, causingwater to also flow in between the phospholipids of the plasmamembrane.b. a type of blue-colored pore in the epidermal surfaces of plants.c. a protein channel in plasma membranes that facilitates the diffusionof water.d. a transport protein, or transporter, in plasma membranes that usesprotons to cotransport water.e. none of the above.arrow_forwardThe mangrove is a type of tree that lives along coasts, with its roots growing in highly saline water (water with lots of dissolved salt). Scientists have recently learned that mangroves are able to undergo a process similar to reverse osmosis in the tips of their roots. As a result, the water entering the mangrove's body is significantly less salty than the water surrounding its roots. As opposed to artificial reverse osmosis, which uses pressure generated by pumps to force water through a membrane, the mangrove's "passive" reverse osmosis uses negative pressure generated by water evaporating from the mangrove's leaves to pull fresh water through membrane-like structures in its roots. Technology based on the red mangrove's version of "reverse osmosis" is already being developed, and there is hope it may lead to a much less energy-intensive method of desalination (removing salt from water). Develop a potential explanation as to why it would be advantageous to the mangrove to desalinate…arrow_forward
- During passive transport, substances will move across a selectively permeable membrane until… explain why A. There is no longer any energy to be used B. All solutes reach the other side of the membrane C. There is no more room inside of the cell D. Equilibrium is reachedarrow_forwardWhen you jump in the bath, water does not run around all your cells and directly into your body. Instead water intake and release is regulated by special proteins called aquaporins. Why can't water run around your cells but instead has this regulation? Select one: a. Water is nonpolar, like our bodies and so cannot mix easily. b. Because we live in a hypertonic environment anyway. c. Desomosomes and gap junctions provide orientation for water movement. d. Our epithelial (skin) cells have tight junctions which form a 'water-tight' seal between cells preventing substances from going around the cell.arrow_forwardWhich of these molecules provides squish to the ECM? a. Elastin b. Hydrated Matrix c. Fibronectin d. Collagen e. Integrinarrow_forward
- part 1 Reaching osmotic balance across a semipermeable membrane for non-charged molecules depends on: a.Relative solute concentration gradient across the membrane b.Relative electrical gradient across the membrane c.Relative solute concentration and electrical gradient across the membrane part 2 The equilibrium of a charged molecule across a semipermeable membrane depends on: a.Relative solute concentration gradient across the membrane b.Relative electrical gradient across the membrane c.Relative solute concentration and electrical gradient across the membranearrow_forwardThe process of “active transport" through a membrane may be described by which of the following? A. the movement of ions and small molecules away from regions where they are in high concentration. B. the use of energy from ATP to move ions and small molecules into regions where they are in lower concentration. C. the plasma membrane engulfs the substance and moves it through the membrane. D. the use of energy from ATP to move ions and small molecules against their concentration gradient.arrow_forwardAn aqueous plant found in its natural environment would be in a solution known as: a. Hypotonic b. Isotonic c. Hypertonicarrow_forward
- Concepts of BiologyBiologyISBN:9781938168116Author:Samantha Fowler, Rebecca Roush, James WisePublisher:OpenStax College