RNA and DNA Flashcards Preview

Biology > RNA and DNA > Flashcards

Flashcards in RNA and DNA Deck (10):

What are the three main components of a nucleotide?

A pentose sugar
A phosphate group
and a nitrogen containing organic base


What does C T G A U stand for



How is a nucleotide formed?

In a condensation reaction.


How does one nucleotide bond with another?

they are joined between the deoxyribose (pentose sugar) of one molecule and the phosphate group of another. This is a phosphodiester bond and one of these forms a dinucleotide, many form a polynucleotide.


What is RNA?

Short polynucleotide chain. where the pentose sugar is a ribose and the organic bases are AGCU.


What are the uses of RNA?

One type transfers genetic information from DNA to ribosomes, RNA also makes up ribosomes and proteins. A third type is involved in protein synthesis.


What is DNA?

Made up of two very long polynucleotides that are joined by hydrogen bonds between the nitrogen bases. the pentose sugar is deoxyribose and the organic bases are A T G and C.


What is base pairing?

When two strands of DNA attatch via hydrogen bonding:
Adenine to thymine (in RNA thymine is uracil)
Guanine to cytosine


Why is DNA stable?

- It has a phosphodiester backbone which protects the more chemically reactive bases inside the double helix
- many hydrogen bonds between the phosphodiester uprights, so hard to separate resulting in a more stable molecule
- 3 hydrogen bonds between cytosine and guanine so the grater the number of c-g binds the more stable the molecule


What is the function of DNA?

- Stable structure, so rarely mutates
- The two strands linked only by h bonds so easier to separate in DNA replication and protein synthesis
Large molecule so can carry lots of info
- The helical cylinder shape allows the deoxyribose backbone to protects the genetic information.