D. Polarity and size.
<span>The size, polarity, and charge of a substance will determine whether or not the substance can cross the cell membrane by diffusion. The cholesterol was an example of a lipid, and is highly soluble in the nonpolar environment of the lipid bilayer. You saw, in the animation above, the cholesterol freely passing into the hydrophobic environment of the membrane. Cholesterol distributes freely in the membrane and then some fraction will dissolve in the aqueous environment of the cytoplasm. Water, on the other hand, while polar, is small enough to cross the membrane at a slow rate. Note that specialized transport proteins in certain cell membranes can provide a channel for the water, greatly increasing its rate of crossing the membrane. The lipid bilayer is much less permeable to the ion, because of its charge and larger size. As a general rule, charged molecules are much less permeable to the lipid bilayer.</span>
Answer:
the salivary glands and the pancreas.
Explanation:
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The answer is 99.
Amino acids <span>contain a carboxyl group (carbon-containing) and an amino group (nitrogen containing). Proteins are made by forming peptide bonds between the carboxyl and amino group of amino acids.
</span>If a protein is made of 100 amino acids, that means there are 99 peptide bonds (because the last, 100th amino acid will not bind the next (101st) amino acid). For each peptide bond that is created, one oxygen atom and two hydrogen atoms are taken. Therefore, one water molecule is created for each peptide bond. If there are 99 peptide bonds, 99 water molecules are created.
Independent Variables are the factors that are tested by beingvaried by the experimenter.
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