2) ADP is similar to rechargeable batteries because it can be continuously combined with inorganic phosphate to produce ATP which is hydrolysed in any energy requiring process back to ADP which can be recombined with inorganic phosphate to reproduce ATP.
3)ATP is manufactured in the mitochondria.
4) Not sure what a macromolecule is. (I did the old GCSE.)
5) From the electron transport chain when electrons gradually lose energy (from photo-excitation) as they are passed from one electron carrier to another.
Errors in transcription are less potentially harmful compared to DNA replication errors because:
1. Unlike DNA, RNA does not permanently store genetic information in the cell.
2. RNA strands have a very short life span. Because of this the errors do not normally have serious impact on the body system.
Also, many copies of RNA are usually made.