DNA UNIT: Learning Outcomes It is expected that students will: name the four bases in DNA and describe the structure of DNA using the following terms: nucleotide (sugar, phosphate, base) complementary base pairing double helix hydrogen bonding

DNA UNIT: Learning outcomes describe DNA replication with reference to three basic steps: "unzipping" complementary base pairing joining of adjacent nucleotides

FOUR DNA NUCLEOTIDES: SUGAR PHOSPHATE BASE

DNA is a polymer:

STRUCTURE OF DNA: Base pairs are bonded in a complementary fashion: A-T & C-G Bonds are hydrogen bonds Sides are made from phosphate and the sugar: deoxyribose Single sugar,phosphate and base unit are called nucleotides

DNA REPLICATION DNA replicates in a semi- conservative manner: each new helix contains one older (parent) strand and one new strand. Enzymes help the process: DNA Polymerase,Helicase, and Ligase. Replication occurs in three steps: 1.Unzipping of parent strand 2. Complementary pairing of new nucleotides 3. Hydrogen bonding between bases

DNA being unzipped and copied:

DNA Unzipping: 1.The enzyme helicase unwinds the parent strand. 2. The enzyme DNA polymerase binds to each strand. 3. New nucleotides are matched in a complementary fashion A-T and C-G. 4. Ligase seals up the phosphate sugar bonds, hydrogen bonds form between nucleotides.

DNA REPLICATION VIDEO

Recombinant DNA DNA that has been recombined through genetic engineering is called Recombinant DNA. Often human DNA is combined with bacterial DNA to get the bacteria to make human proteins for medicine. This process of making Recom. DNA requires special enzymes: restriction enzymes (cut DNA); ligase glues DNA together and DNA polymerase copies DNA.

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