A1.2.3 Sugar–phosphate bonding and the sugar–phosphate “backbone” of DNA and RNA Flashcards
What charge do phosphate groups carry?
Phosphate groups carry a negative charge.
What is the directionality of the sugar-phosphate backbone?
The backbone runs from 5’ to 3’.
What sugar does RNA use?
RNA uses ribose.
How does the negative charge affect the sugar-phosphate backbone?
It makes the backbone hydrophilic, allowing it to interact with water.
What type of bond forms the sugar-phosphate backbone?
Phosphodiester bonds.
How do phosphodiester bonds form?
One bond connects to the 5’ carbon of one sugar and another connects to the 3’ carbon of the next sugar.
How many backbones does DNA have?
DNA has two antiparallel backbones.
What is the effect of the extra OH group in RNA’s ribose?
It makes RNA more chemically reactive and less stable than DNA.
What is the overall charge of the sugar-phosphate backbone?
The backbone has an overall negative charge.
What role does the sugar-phosphate backbone play in stability?
It provides physical protection and chemical stability to the DNA/RNA structure.
What is the key difference between deoxyribose and ribose?
Deoxyribose lacks an oxygen atom at the 2’ carbon position.
What can break the sugar-phosphate bonds?
Specific enzymes called nucleases can break these bonds when needed.
What are the three components of a nucleotide?
A nucleotide consists of a phosphate group, a five-carbon sugar, and a nitrogenous base.
How many backbones does RNA typically have?
RNA usually has a single backbone.
What sugar does DNA use?
DNA uses deoxyribose.
Why is the directionality of the backbone important?
It is crucial for DNA replication and RNA synthesis.
What is a key difference in the stability of DNA and RNA?
DNA is more stable due to the use of deoxyribose, while RNA is more reactive due to ribose.
