The Masked Microbiologist

You're trying to find out the amount of benzoic acid and sodium benzoate to add. Not using the concentrations of your stock solution. You need to find the relative concentrations you need. Start by solving for the ratio [A-]/[HA]. Once you get that, figure out how to use this ratio to determine the relative abundances you need (remember, that is a ratio of one to the other, not one to the total). Hope that helps!

The biological effect depends on where the mutation occurs (where that mispaired base gets put in). If its put into a gene, then there may be a problem. Look up what a codon is, and imagine how changing a base pair may result in a different amino acid being put in (if it is put in the first or second position, not always the third, due to whats called "wobble"). If this affects the folding or the active part of the protein (the part that does the work) it could render it useless. how would this affect the cell? Also, look up sunburns, and other mechanisms like that, where UV radiation affects the body. Pay attention to "thymine dimers" and how this affects the machinery - how DNA and proteins are made. Imagine a train, wtih a rock on the rail. Some, even, are so strong that they literally rip pieces apart. Look up gamma rays, read about how they do damage.