Enzymes that break down DNA catalyze the hydrolysis of the covalent bonds that join nucleotides together. What would happen to DNA molecules treated with these enzymes? a. The two strands of the double helix would separate. b. The phosphodiester linkages of the polynucleotide backbone would be broken. c. The pyrimidines would be separated from the deoxyribose sugars. d. All bases would be separated from the deoxyribose sugars.

Verified step by step guidance

1. Understand the role of enzymes that break down DNA: These enzymes, such as DNase, catalyze the hydrolysis of the covalent bonds that join nucleotides together in a DNA molecule.
2. Identify the type of bonds affected: The covalent bonds targeted by these enzymes are the phosphodiester linkages in the polynucleotide backbone of DNA.
3. Analyze the consequences of breaking phosphodiester linkages: Breaking these bonds results in the cleavage of the DNA backbone, leading to the fragmentation of the DNA into smaller pieces.
4. Evaluate the answer choices in relation to the action of the enzyme: Since the enzyme specifically breaks the phosphodiester bonds, it affects the structural integrity of the DNA strand but does not separate the bases from the sugars or the strands from each other.

Key Concepts

Enzyme Function

Enzymes are biological catalysts that speed up chemical reactions by lowering the activation energy required. In the context of DNA, specific enzymes, such as nucleases, facilitate the hydrolysis of covalent bonds between nucleotides, leading to the breakdown of DNA molecules. Understanding how enzymes interact with substrates is crucial for predicting the outcomes of biochemical reactions.

Covalent Bonds in DNA

DNA is composed of nucleotides linked by covalent bonds known as phosphodiester linkages, which form the backbone of the DNA strand. These bonds connect the phosphate group of one nucleotide to the sugar of the next, creating a stable structure. When enzymes that target these bonds are introduced, they can cleave the backbone, leading to the fragmentation of the DNA molecule.

DNA Structure and Function

DNA consists of two strands forming a double helix, with each strand made up of a sequence of nucleotides. Each nucleotide contains a deoxyribose sugar, a phosphate group, and a nitrogenous base. Understanding the structural components of DNA is essential for comprehending how enzymes affect its integrity and the implications of breaking down its components.