Stimulants are substances that all result in the increase of levels of dopamine in the brain, which is a neurotransmitter that affects attention and pleasure. What this means is that stimulants affect our brain and the way it works by changing the ways that nerve cells communicate. 
Neurons (nerve cells) are the cells that have a role in transmitting messages from the brain to other parts of our body, and vice-versa, which is important for pain response, alertness, energy etc. 
With long-term use, the use of stimulants would affect the central nervous system (speeding it up), the brain, and the functions necessary to live, like respiration, heart rate, blood pressure, body temperature. Levels of neurotransmitters like dopamine, serotonin, and GABA, which are responsible for the regulation of different processes,  are also impacted, which creates a chemical disbalance ultimately resulting in behavioral changes, mood swings, altered attention, movement and energy, stress etc.
So the part of the body that is affected the most with the long-term use of stimulants like cocaine, nicotine, methamphetamine is the brain of course, which is where these substances have the most impact, but the impact on the central nervous system, autonomous nervous system, and neurotransmitter levels is significant.
        
             
        
        
        
Asn or Asp, B	AAT, AAC; GAT, GAC	RAY
 
        
             
        
        
        
your blood which contains a lot of water, carries oxygen to all the cells in your body. 
 
        
                    
             
        
        
        
Answer:
The current answer is b) bacteria need for proper growth and cannot make themselves.
Explanation:
An essential nutrient is one which is required to the cell for the proper growth from the environment because it cannot be synthesized by the cell itself.
Some essential nutrients that bacteria require for their growth are carbon, nitrogen, water, iron, inorganic salts, and many other molecules.  
These nutrients should be given from an easily available source to the bacteria for their proper growth because these nutrients are required to perform essential metabolic activities and can not be synthesized by bacteria on their own.