Answer:
A. The complementary shapes of an enzyme and a substrate
Explanation:
The Lock-and-Key model was made to show how an enzyme's active zone fits a substrate and how they bond together. It correlates just like a lock and a key; you have to have the correct-shaped key in order to open a lock. Same process of thought with the enzymes; you must have the same shape for both in order to bind together,
B. To contrast between the high and low concentration of molecules.
for example a solution with a higher solute concentration than the inside of the cell is called hypertonic
The rigth answer is the picture 4.
In the case of a hypotonic extracellular medium, there will be a large inflow of water to dilute the Na, thereby increasing the cell volume and there will be an explosion of the membrane in places so hemolysis, the contents of the red cell ( Hemoglobin) is released into the blood plasma.
On the other hand, in the case where the extracellular medium is hypertonic, therefore archi concentrated, well it will be the water of the red cell that will come out without damaging the membrane, we will rather have a red cell that is completely flat and non-functional without release. erythrocyte (Hb) content.
