DNA ( the poluymer) consists of 2 chains of nuceotise ( the monomer) line up side by side with the "base" part lined up with each other. 1 ring bases are across from a 2 ring bases. Some bases form 2 hydrogen bonds other form 3 hydrogen bonds.
A = T, C = G
DNA codes for how to make proteins
A mutation is a change in the DNA. A mutation may cause harm to the cell , give the cell an added advantage, or make no change.
If it makes a difference, its not good.
1. Spontaneous mutations
3. By picking up genes from other bacteria
Sometimes errors are made in copying the DNA. Cells have repair enzymes to deal with these errors , but they arent always fool proof and sometimes the mutation remains.
** VIruses dont have repair enzymes so they are prone to mutations.
1. destroying the drug - A mutated enzyme is made that changes the antibiotic in a way that renders it useless.
2. Changing the target of the drug - A normal structure or pathway in the bacteria cell is change due to mutation. antibiotic no longer works
3. Keeping the antibiotic out fo the cell by changing the transporter protein or passageway throught the bacterial envelope and the antibiotic cant enter.
4. by pumping the antibiotic out of the cell before it can damage it.