S: DNA Structure
BC: The End
FC: Banhi Nandi | DNA Structure
1: SB2. Students will analyze how biological traits are passed on to successive generations. | 9th Grade Biology
2: DNA is a polymer, made up of Nucleotides.
3: DNA is a double stranded macromolecule. Two polynucleotide chains, held together by weak thermodynamic forces to form a DNA helix. The two polynucleotide chains run in opposite directions. The sugar-phosphate backbones of the two DNA strands wind around the helix axis and form a sprial staircase. The bases of the individual nucleotides are on the inside of the helix and form the steps of the staircase.
4: Each strand has a direction (known as polarity), 5'- to 3'- from top to bottom
5: Each nucleotide consists of a 5-carbon sugar (deoxyribose), a nitrogen-containing base attached to the sugar, and a phosphate group.
6: There are four different types of nucleotides: A is for adenine G is for guanine C is for cytosine T is for thymine
7: The DNA backbone is alternating sugar-phosphate sequence. The deoxyribose sugars are joined at both the 3'-hydroxyl and 5'-hydroxyl groups to phosphate groups by "phosphodiester" bonds.
8: The deoxyribose sugar of the DNA backbone has 5 carbons and 3 oxygens. Deoxyribose lacks an hydroxyl group at the 2'-position when compared to ribose, the sugar component of RNA.
9: Two different bases are there: Purine and pyrimidine. Cytosine and thymine are pyrimidines. Adenine and guanine are purines.
10: A forms 2 hydrogen bonds with T on the opposite strand, and G forms 3 hyrdorgen bonds with C on the opposite strand.