The correct answer to this is:
“Astrocytes”
Astrocytes also called star cells due to their shape are the
most abundant glial cells in the brain. Extensions from these cells encase
capillaries and offer extra control over which materials enter or leave the
intercellular fluid of the CNS thus acting like a permeability membrane.
Answer: The receptor site is the location that a drug binds to, altering the function of a biomolecule.
Explanation:
The drug receptors site, are the sites where the sites where the drug molecules bind. Basically, a low number of receptors exists and the extent to which the molecules occupy their sites differ with the concentration of drug. The receptor site changes the conformation and function of the binding molecule of the drug.
First, we can eliminate 2 options. The simple unit of protein is amino acid, instead, the simple unit of fat and lipids are fatty acids and glycerol, therfore we can eliminate option A and D because fatty acids does not exist in protein.
Now we are left with B and C. To solve that, we need to understand that protein is made of a chain of amino acids, a lot of amino acids are chemically combined and cannot be broken down unless the use of enzymes. Amino acid are actually the monomers that forms protein.
Therefore, the answer is C. amino acid combine to form a protein chain.