Figure 1.6 presents simplified depictions of nucleotides containing deoxyribose, a nucleotide base, and a phosphate group. Use this simplified method of representation to illustrate the sequence 3'-AGTCGAT-5' and its complementary partner in a DNA duplex.

How many phosphodiester bonds are present in this DNA duplex?

Key Concepts

Nucleotides

Nucleotides are the building blocks of DNA and RNA, consisting of three components: a sugar (deoxyribose in DNA), a phosphate group, and a nitrogenous base. In DNA, the sequence of these nucleotides encodes genetic information. Understanding the structure of nucleotides is essential for illustrating DNA sequences and recognizing how they pair with complementary strands.

Complementary Base Pairing

Complementary base pairing refers to the specific pairing of nitrogenous bases in DNA: adenine (A) pairs with thymine (T), and guanine (G) pairs with cytosine (C). This pairing is crucial for the formation of the double helix structure of DNA and ensures accurate replication and transcription of genetic information. Recognizing these pairs is necessary for determining the complementary sequence of a given DNA strand.

Phosphodiester Bonds

Phosphodiester bonds are covalent linkages that connect the phosphate group of one nucleotide to the sugar of another, forming the backbone of the DNA strand. Each bond is formed during DNA synthesis and is essential for maintaining the integrity and stability of the DNA molecule. The number of phosphodiester bonds in a DNA duplex can be calculated based on the number of nucleotides present in each strand.