How changes in pH can affect the rate of enzyme reactions

Q9. Explain how changes in pH can affect the rate of enzyme reactions. How would you be able to demonstrate this in the lab? (300 words)
To meet a/c 6.1:-
Q11. Draw a diagram to show how DNA is replicated before a cell divides. Label and annotate your diagram to explain how replication happens.
Q12. Draw a flow diagram to show how DNA is involved in protein synthesis. Start with the DNA present in chromosomes in the nucleus and show the different stages involved to produce a protein in the cytoplasm.