Deoxyribonucleic Acid BIOLOGY 12 Deoxyribonucleic Acid

Amazing Facts about DNA DNA has a width of 2nm, with the bases 0.34nm apart (1nm = 0.000001cm) the human genome consists of an estimated 3 billion base pairs it would take a person typing 60 words per minute, 8 hours a day, for 50 years to type out the human genome

the DNA in one human cell would have a total length of 1.7 meters if you unwrap all the DNA in all of your cells, it would reach the moon 6000 times red blood cells are the only cells in the human body that do not have DNA

DNA Deoxyribonucleic Acid a double stranded polymer of nucleotides carries that genetic information of an organism

Nucleotides 3 Parts of a Nucleotide: deoxyribose sugar phosphate group nitrogenous base Thymine Adenine Cytosine Guanine

Nucleotides

Nitrogenous Bases Purines: characterized by a double ring Adenine and Guanine Pyrimidines: characterized by a single ring Thymine and Cytosine

Nitrogenous Bases Purines Pyrimidines

Base Pairings Adenine and Thymine Cytosine and Guanine Purines only pair with Pyrimidines. Only pair this way because of bonds. A and T form 2 hydrogen bonds. C and G form 3. page 210 and 213

Base Pairings

DNA Structure the deoxyribose sugar is a five-carbon ring each carbon is numbered 1 prime (1’) through to 5 prime (5’) the nitrogenous base is attached to the 1’ carbon by a glycosyl bond the phosphate group is attached to the 5’ carbon by an ester bond

DNA Structure DNA is a double helix backbone is composed of the sugar and phosphate groups stabilized by hydrogen bonds between the bases

DNA Structure each strand has a direction DNA strands are antiparallel the direction of one strand is opposite to the direction of the other strand 5’ end – terminates with a phosphate group 3’ end – terminates with a hydroxyl group

Questions Page 216 #2, 3, 5, 6, 7