Answer:
<h2>C. placing carrier proteins in the membrane.</h2>
Explanation:
If there is no barrier preventing molecules from moving molecules, then there will be large movement of molecules from an area of high concentration to an area of low concentration. This passive process is known as diffusion. The phospholipid bilayer of a cell's membrane works as a barrier to large molecules, ions, and most hydrophilic molecules. Whereas small hydrophobic molecules can pass freely through the phospholipid bilayer, other molecules and ions are transported across the cell membrane with the help of transport proteins. Some transport proteins, allowing hydrophilic molecules and ions to passively move through them and across the cell membrane.
Examples: carrier proteins and channel proteins.
Placing carrier proteins in the cell membrane will allow the molecule to reach equal concentrations on the both the sides of the membrane and maintain that way over long time. In contrast, transport proteins known as pumps will use cellular energy, usually in the form of ATP, to transport molecules.
Placing equal numbers of intracellularly directed and extracellularly directed pumps would also equalize the concentrations of a molecule long over time. Pumps are to transport molecules against their concentration gradient, such as the sodium-potassium pump continuously moves sodium ions out of a cell.
Through the use of carrier proteins, there is equalization of concentrations of a hydrophilic molecule. This equalize the numbers of molecules on the inside and outside of the cell, but the pumps would continue moving the molecule inward, eventually resulting in more molecules inside of the cell than out.
Plants leaves, roots and stems are in the organ systems level.
—Evidence—
•] Plants contain just two organ systems. The shoot system includes all of the parts above the ground, such as leaves and stems, while the root system includes all of the parts below the ground, such as roots and tubers.
The answer is A Plants use carbon and release oxygen, and animals release carbon and uses oxygen
Answer:
the last answer
Explanation:
because f,g,h both come from a so you can be sure
