RNA and DNA

Question 1

What are the three main components of a nucleotide?

Answer 1

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

Question 2

What does C T G A U stand for

Answer 2

cytosine 
thymine 
uracil 
adenine 
guanine

Question 3

How is a nucleotide formed?

Answer 3

In a condensation reaction.

Question 4

How does one nucleotide bond with another?

Answer 4

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.

Question 5

What is RNA?

Answer 5

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

Question 6

What are the uses of RNA?

Answer 6

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

Question 7

What is DNA?

Answer 7

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.

Question 8

What is base pairing?

Answer 8

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

Question 9

Why is DNA stable?

Answer 9

• 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

Question 10

What is the function of DNA?

Answer 10

• 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.