Structure of DNA

Structure of DNA - paired with a...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Structure of DNA DNA is composed of units called nucleotides. Each nucleotide contains a phosphate group, a deoxyribose sugar, and a nitrogenous base. The nucleotides joined together to form a chain. The phosphate end of the chain is referred to as the 5' end. The opposite end is the 3' end. DNA is composed of two chains of nucleotides linked together in a ladder-like arrangement with the sides composed of alternating deoxyribose sugar and phosphate groups and the rungs being the nitrogenous bases as indicated by the diagram below.
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
The "A" of one strand is always paired with a "T" on the other. Similarly, the "G" of one strand is
Background image of page 2
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: paired with a "C" on the other. The two strands are held together by hydrogen bonds (electrostatic attraction). Two hydrogen bonds hold adenine to thymine. Three bonds attach cytosine to guanine as indicated in the diagram above. During the process of cell division, the DNA becomes tightly coiled, forming structures called chromosomes . The diagram below is a portion of a double-stranded chromosome showing the centromere and a portion of the base sequence. The diagram does not show the extensive looping and coiling and the proteins associated with coiling. Notice that the base sequence in the two chromatids is identical....
View Full Document

Page1 / 2

Structure of DNA - paired with a...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online