DNA Replication

Supercoiled DNA

Why do we need more DNA? Each new cell that is created, needs its own set of DNA.

Enzymes control the world! 3 Steps in Replication 1 st - A DNA HELICASE “unzips” the DNA, by cutting the hydrogen bonds between the bases.

2 nd - The enzyme DNA POLYMERASE finds a correct, new base and attaches it to the old DNA strand.

3 rd - The DNA polymerase “proof reads” for any mistakes in the newly made DNA.

“Mistakes” are MUTATIONS! Original: The fat cat ate the wee rat. Mutation:The fat hat ate the wee rat. The mistake can result in a wrong protein being produced or…

Mutations can result in… There are many types of mutations that change not the protein itself but where & how much of a protein is made. These types of changes in DNA can result in proteins being made at the wrong time or in the wrong cell type. Changes can also occur that result in too much or too little of the protein being made.

Semi-Conservative Replication Each new DNA helix produced contains one original strand and one newly created strand. BLUE = OLD YELLOW = NEW