Basically how many types of enzymes have been recognised by the International Union of Biochemistry?

Which of the following processes are affected by temperature?

The given graph shows the effect of substrate concentration on the rate of reaction of the enzyme green-gram-phosphatase. What does the graph indicate?

What is an enzyme that catalyzes hydrolysis called?

Match the following Column-$I$ with Column-$II$ and select the correct option.

Column-$I$	Column-$II$
$(A)$ Transferases	$(i)$ $H_4P_2O_7$ related reactions
$(B)$ Lyases	$(ii)$ Hexokinase
$(C)$ Isomerases	$(iii)$ Cytochrome oxidase
$(D)$ Ligases	$(iv)$ Aldolase
$(E)$ Oxidoreductases	$(v)$ Glucose-$6$-phosphate $\rightarrow$ Fructose-$6$-phosphate

Enzymes are proteins. Proteins are long chains of amino acids linked to each other by peptide bonds. Amino acids have many functional groups in their structure. Many of these functional groups are ionisable. As they are weak acids and bases in chemical nature,this ionisation is influenced by the $pH$ of the solution. For many enzymes,activity is influenced by the surrounding $pH$. This is depicted in the curve below. Explain briefly.