The circumference of earth is 24,901 mi
Answer:
B.
Explanation:
Cell A has a cell wall, Cell B has no cell wall, and Cell C has a fungal cell wall.
The correct order is:
- Action potential arrives at the axon terminal.
- Calcium ions enter the axon terminal.
- Synaptic vesicles fuse to membrane of axon terminal.
- Acetylcholine is released into the synaptic cleft.
- Acetylcholine binds to its receptors on the junctional folds.
- Junctional folds become depolarized.
- Action potential is initiated on the sarcolemma.
Action potential travels through the membrane of the presynaptic cell causing the channels permeable to calcium ions to open. Ca2+ flow through the presynaptic membrane and increase the Ca concentration in the cell which will activate proteins attached to vesicles that contain a neurotransmitter (e.g. acetylcholine). Vesicles fuse with the membrane of the presynaptic cell, thereby release their contents into the synaptic cleft-space between the membranes of the pre- and postsynaptic cells. Neurotransmitter binds to its receptors on the postsynaptic membrane and its binding causes depolarization of the target cell (muscle cell).
After a quick search, I was able to find a source with your question and its multiple choice answers
Next time, you should include them, it is helpful!
"Which describes the action of a ligand's competitive antagonist?"
-A.) It decreases the amount of ligand required to activate the protein.
-B.) It blocks the binding of the ligand to its binding site and prevents activation of the protein.
-C.) It binds to a different binding site on the protein, altering the protein shape so that a ligand cannot bind.
D.) When present, it increases the binding of a ligand to its receptor.
Your answer would be "B".
