Answer:
and why are u so happy today ????
Explanation:
Answer:
Water is taken up through the xylem until it reaches a leaf, where it diffuses out into the surrounding mesophyll cells. Water diffuses from the mesophyll cells to the surrounding intercellular air spaces as water vapour, and finally, out of the leaf through the stomata.
Explanation:
___________
The embedded proteins <u>allow specific substances to flow into the cell</u>.The phospholipid bilayer forms a stable barrier between two aqueous compartment.They embedded proteins carry the selective transportation of molecules and ensure their is cell to cell recognition.
Complete question:
The endplate potential (EPP) at the frog neuromuscular junction occurs because ACh simultaneously increases the conductance of the postsynaptic membrane to Na and K
Answer:
TRUE
Explanation:
The Acetylcholine neurotransmitter is released from the presynaptic cell by the process of exocytosis.
Once the molecule is in the intercellular space, it moves forward the postsynaptic membrane to join its receptor in the motor plate.
Once the joining has occurred, the receptor acquires a channel shape allowing the ion transference that will make possible the modification of the action potential. Ions traffic will consist of the pass of sodium and calcium to the interior of the cell and potassium to the exterior. Quantitatively, the interchange Na-K is the most significant.
K+ follows a concentration gradient, while Na+ follows an electrochemical gradient. The interchange results in an increase of positive charges in the interior of the muscular cell.
Whenever there is a sufficient number of Acetylcholine receptors are active, the depolarization threshold of the motor endplate is exceeded. This activates an action potential that extends to the rest of the muscle membrane.
