Which element is present in the structure of thiamine and biotin?

Match the following.

Column-$I$	Column-$II$
$(a)$ Nitrogen	$(1)$ Activation of some enzymes
$(b)$ Potassium	$(2)$ For the work done by $F_1$
$(c)$ Phosphorus	$(3)$ Ionic balance
$(d)$ Calcium	$(4)$ In structure of vitamin

$Mg^{2+}$ is an activator of:
$I.$ Alcohol dehydrogenase
$II.$ Nitrogenase
$III.$ Ribulose bisphosphate carboxylase oxygenase
$IV.$ Phosphoenol pyruvate carboxylase
Choose the correct option.

Which of the following mineral elements plays an important role in the synthesis of $ATP$ and carbohydrates?

Which one of the following elements is necessary for the translocation of sugars in plants?

Fluorine helps in maintaining the: