Which one of the following is an antioxidant vitamin?

Which of the following protects from scurvy?

Match the following:

Column $I$	Column $II$
$(a)$ Aquaporin	$(i)$ Amide
$(b)$ Asparagine	$(ii)$ Polysaccharide
$(c)$ Abscisic acid	$(iii)$ Polypeptide
$(d)$ Chitin	$(iv)$ Carotenoids

Select the correct option:

Molecules are always moving. Some molecules move faster than others; . . . . . . is a measure of their average velocity of movement.

$A$ pyrophosphate cleavage takes place when

The nitrogen content of urea is: (in $\%$)