Answer;
d. the specific geometry and types of amino acids in the active site
Explanation;
-Enzymes are highly selective catalysts, meaning that each enzyme only speeds up a specific reaction. The molecules that an enzyme works with are called substrates. The substrates bind to a region on the enzyme called the active site.
-For a substrate to bind to the active site of an enzyme it must fit in the active site and be chemically attracted to it. The shape of an enzyme determines how it works. Enzymes have active sites that substrate molecules (the substances involved in the chemical reaction) fit into when a reaction happens.
Answer:

Explanation:
We usually approximate the density of water to about
at room temperature. In terms of the precise density of water, this is not the case, however, as density is temperature-dependent.
The density of water decreases with an increase in temperature after the peak point of its density. The same trend might be spotted if the temperature of water is decreased from the peak point.
This peak point at which the density of water has the greatest value is usually approximated to about
. For your information, I'm attaching the graph illustrating the function of the density of water against temperature where you could clearly indicate the maximum point.
To a higher precision, the density of water has a maximum value at
, and the density at this point is exactly
.
Answer:
The empirical formula is the simplest form;
Given:
Oxygen O at 94.1% and
H at 5.9%
Assume 100grams.
94% = 0.941 x 100gm. = 94.1 gm x 1mole/16gm. = 5.88 moles of O
5.9% = 0.059 x 100gm. = 5.9gm. X 1moleH/1.002gm. = 5.88 moles of H
There is one mole of O for each mole of H so the empirical formula is 
and written as OH.
Look at the periodic table to find the charge on atoms.
Magnesium is +2 and Nitrogen is -3. Since there are two nitrogen charge 2*-3 = -6 there needs to be 3 Mg then (3*2+ = 6+) to pair with the two nitrogen.
3 Mg(+2) + 2 N(-3) = Mg3N2
Your answer is C. Both gasoline and litter would need to be physically separated from the water, because neither bonds with the water.