Answer:
The two main reasons are nonpolar core of the bilayer and the active transport.
Explanation:
The membrane is structured to have two outer layers that are polar and an inner layer that is nonpolar.
If a membrane protein is exposed to the solvent, i<em>t will also have a polar side. It would be very difficult for the polar face of the membrane to move through the nonpolar core of the bilayer.</em> Therefore, this model is not feasible.
One major form of transport, active transport, moves solutes up the concentration gradient. <em>The binding of a solute and then release on another side of the membrane would only work for facilitated diffusion because it would cause a net movement of solutes down the concentration gradient.</em> It is unclear how energy could be expended to drive this process in the transverse carrier model.<em> Therefore, the transverse carrier model does not explain active transport.</em>
Amino acids are acids on one hand, and a base on the other hand.
<h3>What is an acid?</h3>
An acid is a substance that produces hydrogen or hydroxonium ions as the only positively charged ion when it ionizes.
All amino acids have an amine group -
and a carboxylic group -
.
The carboxylic group ionizes such that:

The presence of the amine group enables amino acids to also act as a base.
More on amino acids can be found here: brainly.com/question/14583479
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The answer is (A) virus. In the medical field, it's considered non-living.
B: They occur more quickly than reactions without enzymes
Answer:
Gizzard and crop
Explanation:
I just answered that question.