$A$ deficiency of which of the following causes continuous bleeding from an injured part of the body?

Which of the following substances is found in fruit juices?

Match the following:

$(a)$ Inhibitor of catabolic reaction	$(i)$ Ricin
$(b)$ Contains peptide bond	$(ii)$ Malonate
$(c)$ Cell wall material in fungi	$(iii)$ Chitin
$(d)$ Secondary metabolite	$(iv)$ Collagen

Select the correct option:

Which property of water is responsible for maintaining the homogeneity of the cytoplasm?

Pellagra is caused by the deficiency of

The given structure represents a low molecular weight organic compound found in living tissues. Identify the category and the missing component $X$ in the structure.
Category $-$ Component