Question

explain structure of DNA (sugars, phosphates, placements, etc what 3' and 5' mean)

Answer 1

Answer: - Structure of DNA.

The basic building block of DNA is called a nucleotide. A nucleotide is made up of several smaller molecules that include a five carbon sugar called deoxyribose, a phosphate molecule and four different nitrogenous bases (adenine, thymine, cytosine, and guanine). DNA consists of 2 polynucleotide chains or strands. Nucleotides are attached together to form two long strands that wound together to create a structure called a double helix. The shape of this double helix resembles a twisted ladder. The sugar-phosphate backbones of the DNA strands constitute the outside of the helix and the nitrogenous bases form the inside. Hydrogen bonding between nitrogenous base pairs holds the DNA strands together. Adenine and thymine are paired by two H bonds, whereas cytosine and guanine are paired by three H bonds. Both the stands are arranged in an antiparallel manner meaning if one of the strands is arranged from 5'-3' direction then the other stand attached to it will be arranged in 3'-5' direction. A 5' and 3' indicates the carbon numbers in the DNA's sugar backbone. The 5' carbon has a phosphate group attached to it and the 3' carbon a hydroxyl (-OH) group. The pictures below makes the understanding of DNA structure easy to understand.

* Images are taken from google search