Fumarase enzyme belongs to which class?

The given graphical representation relates to enzyme activity under three conditions ($pH$,temperature,and substrate concentration). What do the given axes $X$ and $Y$ represent?
$X$-axis $-$ $Y$-axis

Select the correct match for $X$ and $Y$:

Column $X$	Column $Y$
$(1)$ Transferases	$(P)$ Maltase
$(2)$ Hydrolases	$(Q)$ Hexokinase
$(3)$ Lyases	$(R)$ Fructose isomerase
$(4)$ Isomerases	$(S)$ Aldolase

At which temperature do enzymes lose their native conformation?

The enzyme phosphoglucomutase belongs to which of the following classes?

Which enzyme catalyzes the transfer of a group from one substrate to another?