Q33 / 160 · AP EAMCET 2019 (20 Apr Shift 1) · Chemistry

Identify the correct set of monosaccharides present in sucrose \((X)\), lactose \((Y)\) and maltose \((Z)\).

  • A
    \(\begin{array}{|c|c|c|c|} \text{X} & \text{Y} & \text {Z} \\ \begin{array}{l} \text { glucose, } \\ \text { fructose } \end{array} & \begin{array}{l} \text { galactose, } \\ \text { glucose } \end{array} & \begin{array}{l} \text { glucose, } \\ \text { fructose } \end{array} \end{array}\)
  • Correct answer
    B
    \(\begin{array}{|c|c|c|c|} \text{X} & \text{Y} & \text {Z} \\ \begin{array}{l} \text { glucose, } \\ \text { fructose } \end{array} & \begin{array}{l} \text { galactose, } \\ \text { glucose } \end{array} & \begin{array}{l} \text { glucose, } \\ \text { glucose } \end{array} \end{array}\)
  • C
    \(\begin{array}{|c|c|c|c|} \text{X} & \text{Y} & \text {Z} \\ \begin{array}{l} \text { glucose, } \\ \text { glucose } \end{array} & \begin{array}{l} \text { galactose, } \\ \text { glucose } \end{array} & \begin{array}{l} \text { glucose, } \\ \text { glucose } \end{array} \end{array}\)
  • D
    \(\begin{array}{|c|c|c|c|} \text{X} & \text{Y} & \text {Z} \\ \begin{array}{l} \text { galactose, } \\ \text { glucose } \end{array} & \begin{array}{l} \text { glucose, } \\ \text { fructose } \end{array} & \begin{array}{l} \text { glucose, } \\ \text { glucose } \end{array} \\ \end{array}\)

Solution

\((X) \longrightarrow\) Sucrose on hydrolysis gives glucose and fructose. i.e. Sucrose \(\longrightarrow\) glucose + fructose \((Y) \longrightarrow\) Lactose on hydrolysis gives D-glucose and D-galactose. i.e. Lactose \(\longrightarrow\) D-glucose + D-galactose \((Z) \longrightarrow\) Maltose on hydrolysis gives 2 units of glucose. i.e. Maltose \(\longrightarrow\) glucose + glucose Thus, correct option is (b).

Hence, the correct answer is option: 'B'.

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