RNA and DNA Flashcards Preview

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Flashcards in RNA and DNA Deck (10):
1

What are the three main components of a nucleotide?

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

2

What does C T G A U stand for

cytosine
thymine
uracil
adenine
guanine

3

How is a nucleotide formed?

In a condensation reaction.

4

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.

5

What is RNA?

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

6

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.

7

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.

8

What is base pairing?

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

9

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

10

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.