The right answer is: voltage-gated channels
Ionic channels are membrane proteins that allow the selective passage of the cell membrane by ions (Na +, Ca2 +, K +, Cl-, ...) following the electrochemical gradients. They play a vital role in cellular excitability, triggering and propagation of action potential. They intervene in the coupling excitation-contraction and excitation-secretion. Ion channel selectivity is based on the adequacy of ion size and charges with the structure and amino acid sequence of the channels.
Among these channels, there are voltage-gated channels.
These are ion channels whose opening is activated by the membrane potential.
These dependent volumetric channels are characterized:
- by the selectivity of the ions (Ca2 +, Na +, K +, Cl-, ...)
- by their conductance
- by their activation domain (significant depolarization to low)
- by their kinetics of inactivation (slow, fast or transient)
<span>I believe the answer is A. hydrophobic. Inside the biological membranes are lipids (hydrophobic) molecules. As you may know the membranes are lipid bilayers. In order to place proteins, which are polymers of amino acids, you would need to create an like-to-like environment. The R groups of amino acids will interact with this hydrophobic lipid bilayer environment and will need to display the same characteristics to keep the plasma membrane intact and not cause unwanted disruption. Therefore, R groups of amino acids in biological membranes should be hydrophobic. </span>
Answer:
A. Controls what goes into and out of the cell
Explanation:
If what you are referring to is the image attached, then the answer would be A. The structure that is labelled A is called the cell membrane.
The cell membrane is what we call semi-permeable. This means that some materials can go through them and others cannot without the help of other factors. The cell membrane encases the cell and protects the cell. It lets nutrients, minerals, and waste to move in and out of the cell.
Other choices:
B describes the cytoplasm.
C describes the nucleus
D describes the vacuole
False: RNA contains only the ribose sugars, whereas DNA only deoxyribose, hence their different names
