Answer:standard amino acids is an amino acid used in the synthesis of peptides
Explanation: There are twenty standard amino acids which are
ALA, ARG, ASN, ASP, CYS, GLN,GLU,GLY, 
 
        
             
        
        
        
 
the purpose of a cell membrane is to 
 
The cell membrane gives the cell its structure and regulates the materials that enter and leave the cell. Like a drawbridge intended to protect a castle and keep out enemies, the cell membrane only allows certain molecules to enter or exit.
 
        
             
        
        
        
The tendency to maintain a stable, relatively constant internal environment is called homeostasis. The body maintains homeostasis for many factors in addition to temperature. For instance, the concentration of various ions in your blood must be kept steady, along with pH and the concentration of glucose.
        
                    
             
        
        
        
Answer:
the cell membrane becomes depolarized. 
Explanation:
Na+ moves in, K+ moves out. 
hope it helps! 
 
        
                    
             
        
        
        
All except number 2. Hope this helps!