Indicate the net charge of lysine at pH 9.5.

Explanation:

An amino acid like lysine has both the acidic and basic group . They are amphoteric in nature ie they can react with both acid and base . In acidic or basic medium they carry charge of either positive or negative nature .

Lysine is also an amino acid . It has both acidic and basic group . The pka value of its basic side chain is 10.5 . Hence at pH more than it it is neutral or have no charge but at pH value less than 10.5 , it acquires H⁺ ion and becomes positively charged

Hence at pH value of 9.5 which is less than 10.5 , it will be positively charged . It will have net charge of + 1 .

   NH₂  + H⁺ =     NH₃⁺

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