Liquid as first of all, the particles aren't compact ( which would mean solid) nor are they spread out ( which would mean gas) nor is it plasma as we aren't given protons or electrons.
 
        
             
        
        
        
<span>Amylase needs an optimum pH for its activity. It is in the range of 6-7. Below or above pH will denature this enzyme. The pH level is optimum for this enzyme in the mouth and hence it catalyses the break down of sugar. The pH level of stomach is lower than its optimum level duet to the activity of gastric acid. Hence the enzyme becomes inactive in the stomach.</span>
        
             
        
        
        
Answer: A semi-permeable membrane is that which only allows certain
                substances to pass through.
 
        
                    
             
        
        
        
I believe that would be irritability.