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Multiple Choice
The DNA double helix does not have which of the following structural features?
A
Hydrogen bonds
B
Phosphodiester bonds
C
Major and minor grooves
D
Beta sheets
Verified step by step guidance
1
Understand the structure of the DNA double helix: DNA is composed of two strands that coil around each other to form a double helix. Each strand is made up of nucleotides, which include a phosphate group, a sugar molecule, and a nitrogenous base.
Identify the types of bonds present in DNA: The backbone of each DNA strand is formed by phosphodiester bonds, which link the sugar of one nucleotide to the phosphate group of the next. Hydrogen bonds occur between complementary nitrogenous bases on opposite strands, holding the two strands together.
Recognize the presence of major and minor grooves: The double helix structure of DNA creates two types of grooves, known as the major and minor grooves. These grooves are important for protein binding and DNA interactions.
Understand what beta sheets are: Beta sheets are a type of secondary structure found in proteins, not in DNA. They are formed by hydrogen bonds between different segments of a polypeptide chain, creating a sheet-like structure.
Conclude that beta sheets are not a feature of DNA: Since beta sheets are a structural feature of proteins and not DNA, they are not present in the DNA double helix. Therefore, the correct answer is that the DNA double helix does not have beta sheets.