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The structure of $L -(-)$-glucose is
$(1)$ $\begin{matrix}
C{{H}_{3}} \\
|\,\,\,\,\,\, \\
ZNH\,C\,HC{{O}_{2}}H \\
\end{matrix}$ $(2)$ $\begin{matrix}
C{{H}_{3}}\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, \\
|\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, \\
{{H}_{2}}N\,C\,HC{{O}_{2}}C{{H}_{2}}{{C}_{6}}{{H}_{5}} \\
\end{matrix}$
$(3)$ $\begin{matrix}
\,\,\,\,\,\,\,\,\,\,\,\,C{{H}_{3}}{{C}_{6}}{{H}_{5}} \\
|\,\,\,\,\, \\
ZNH\,C\,HC{{O}_{2}}H \\
\end{matrix}$ $(4)$ $\begin{matrix}
C{{H}_{2}}{{C}_{6}}{{H}_{5}}\,\,\,\,\, \\
|\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, \\
{{H}_{2}}N\,CHC{{O}_{2}}C{{H}_{2}}{{C}_{6}}{{H}_{5}} \\
\end{matrix}$
$(i)$ Glucose $+ ROH \quad \stackrel{\text { dry } HCl }{\longrightarrow}$ Acetal
$\xrightarrow[{{{\left( {C{H_3}CO} \right)}_2}O}]{{x\,eq.of}}$ acetyl derivative
$(ii)$ Glucose $\xrightarrow{{Ni/{H_2}}}A\xrightarrow[{{{\left( {C{H_3}CO} \right)}_2}O}]{{y\,\,eq.\,of}}$ acetyl derivative.
$(iii)$ Glucose $\xrightarrow[{{{\left( {C{H_3}CO} \right)}_2}O}]{{z\,ed.\,of}}$ acetyl derivative.
$' x ^{\prime},{ }^{\prime} y ^{\prime}$ and ${ }^{\prime} z^{\prime}$ in these reactions are respectively.
$(1)$ Denaturation of proteins causes loss of secondary and tertiary structures of the protein.
$(2)$ Denaturation leads to the conversion of double strand of $DNA$ into single strand.
$(3)$ Denaturation affects primary structure which gets distorted.