DNA structure and Replication

DNA has what structure…

Has a Double Helix and phosphodiester

DNA polymerase

Add as a new DNA Strand

Base pairing between DNA strand?

Adenine, Thymine, Cytosine, Guanine

Helicase does what?

Separate the DNA Into two Strand
Creating a fork shape.

Leading strand

Synthesis is continuous 5'to’3

Lagging strand?

Synthesis involves okazaki fragment 3’ to ‘5

Primase

Serve as a starting Point for DNA Synthesis.

Telomerase

Helps the talomere to continue cell division without shorten (slowing aging)

Nucleotide is made of what?

Sugar, Phosphate group, Nitrogenous base.

Anti-parallel

Moving opposite from each other.

DNA ligase

Joins Okazaki fragments on the lagging strand.

Mutation

A mutation is a change that occurs in our DNA sequence, either due to mistakes when the DNA is copied or as the result of environmental factors such as UV light and cigarette smoke.

Methylation

Helps Polymerase to distinguish between old and new strand

Telomores

Are protective caps at the ends of chromosomes. They Shorten due to cell division

Polymorphism

• Genetic change that occur in more than 1% os the Population.

• Its responsible for many differences, between people, eye color, hair color, and blood type.

Mosaicism

Somatic mutations that happen in a Single cell early in embryonic development can lead to situation called mosaicism.

Hereditary mutation

Change that ls Inherited from a parent and are present through out a person's life in virtually every cell in the body.

Proofreading

Correct errors during replication. (DNA Polymerase)

Major Mutations types

Substitution, Deletion, Insertion, Translocation.

Nucleotide Excision

Repairs thymine dimers when exposed to UV.

Mismatch Repair

Sometimes the Incorrectly added base is detected after replication. So the mismatch repair those incorrect added base.