<span>amount of nitrogen, oxygen, and other elements dissolved in the water. Hope this helps!</span>
        
             
        
        
        
<em>Hardness is a measure of how resistant solid matter is to various kinds of permanent shape change when a force is applied</em> <em>Macroscopic hardness is generally characterized by</em> <em>strong intermolecular bonds</em>, <em>but the behavior of solid materials under force is complex; therefore,</em> <em>there are different measurements of hardness</em>: <em>scratch hardness, indentation hardness, and rebound hardness. Hardness is dependent on ductility, elastic stiffness, plasticity, strain, strength, toughness, viscoelasticity, and viscosity. Common examples of hard matter are ceramics, concrete, certain metals, and super hard materials, which can be contrasted with soft matter.</em>
 
        
             
        
        
        
The author assumes that the question can be answered by applying principles of anatomy, physics and evolutionary biology. First reason he suggests is that cats are small and they have a favourable mass-surface area ratio. Next, he suggests that cats have soft tissues that absorb the shock and they land on all four limbs, dividing the shock. This is because of their body shape and its centre of gravity. He says that felines have this kind of body structure (that canines lack) because years of falling from trees etc. has evolved their body in this way. 
 
        
             
        
        
        
Answer & explanation:
Amylase is part of enzymes, a group of large peptide molecules (formed by amino acids) whose role is to catalyze reactions in order to facilitate the synthesis of other biological molecules.
Amylase is found mainly in saliva (in the form of salivary amylase, or ptialin), acting in the breakdown of starch and glycogen in foods, reducing them to smaller particles, facilitating their digestion and absorption. 
The action of enzymes depends on certain specific conditions, called optimal conditions. In the case of <u>amylase</u>, it depends on an optimum pH of 7 (neutral) and an optimum temperature of approximately 37 ° C. 
This enzyme can still act between 35 ° C and 40 ° C, but below 35 ° C it is inactivated, preventing its functions from being performed, and above 40 ° C it suffers denaturation, causing changes in its structures.
Thus, it is concluded that the <u>temperature</u> (under optimal conditions) is important for enzymes because it keeps their actions and structures in proper operation.