Question

Dna double helix is composed of two strands of dna; each strand is a polymer of dna nucleotides. each nucleotide consists of a sugar, a phosphate group, and one of four nitrogenous bases. the structure and orientation of the two strands are important to understanding dna replication. drag the

Answer 1

DNA is structured as a double helix, with two strands made up of nucleotide monomers linked together. These strands run antiparallel and are connected by hydrogen bonds between the complementary nitrogenous bases. The double helix's shape and strand orientation are essential for DNA replication and genetic information processing.

Step-by-step explanation:

DNA Structure and Replication

The double helix is a fundamental structure of DNA, consisting of two antiparallel strands of nucleotides, which are twisted around each other. Each nucleotide is composed of three components: a five-carbon sugar called deoxyribose, a phosphate group, and one of four nitrogenous bases: adenine (A), thymine (T), cytosine (C), or guanine (G). The two strands are connected via hydrogen bonds between the complementary pairs of these nitrogenous bases where adenine always pairs with thymine, forming two hydrogen bonds, and guanine always pairs with cytosine, forming three hydrogen bonds. The sugar and phosphate groups create the backbone of the DNA molecule, which is on the exterior, while the bases are on the interior, paired in a way that resembles the steps of a staircase.

Each strand of DNA has a directionality, with one end being the 5' end, where a free phosphate group is attached, and the other being the 3' end, with a free hydroxyl group. This antiparallel orientation is crucial for DNA replication and various nucleic acid interactions. Understanding the precise arrangement and orientation of these strands is essential as it is directly related to how DNA replicates and transfers genetic information.

Answer 2

The DNA double helix is constructed from two strands of DNA, each with a sugar-phosphate backbone and nitrogenous bases that form hydrogen bonds, holding the two strands together. Each DNA strand has two unique ends. The 3' end has a hydroxyl (-OH) group on the deoxyribose sugar, whereas the 5' end has a phosphate group. In the double helix, the two strands are antiparallel, that is, they run in opposite directions such that the 3' end of one strand is adjacent to the 5' end of the other strand.