Deoxyribonucleic Acid Structure of DNA Deoxyribonucleic Acid

DNA Found in the nucleus of eukaryotic cells Found in the cytoplasm of prokaryotic cells DNA coils around histones (proteins)to make chromosomes A segment of DNA is called a gene

DNA Structure DNA (Deoxyribose nucleic acid) is arranged in a double helix or “twisted ladder.” Scientists Watson and Crick discovered this structure in 1953. They received the Nobel Prize for this.

Subunits of DNA DNA is a long molecule made up of subunits called nucleotides (3 parts) phosphate five-carbon sugar (deoxyribose) nitrogen base (there are 4 different nitrogen bases)

Nitrogen Bases Purine-double ring of C and N atoms Guanine (G) Adenine (A) Pyrimidines-single ring of C and N atoms Cytosine (C) Thymine (T)

The ladder The sides of the DNA chain are made of alternating sugars and phosphates. It is referred to as the sugar-phosphate backbone. The rungs of the “ladder” are made up of the nitrogen bases joined by weak hydrogen bonds. These bonds will only be formed between specific pairs of bases.

Base Pairing Rules Adenine always bonds with Thymine (2 H bonds) Guanine always bonds with Cytosine (3 H bonds)

DNA Vocabulary Foldable Create a foldable for the words/phrases provided. FOR THE BASES TELL WHAT IT PAIRS WITH AND IF IT’S A PURINE OR PYRIMIDINE