Nucleic Acids

Question 1

What is the basic function of DNA?

Answer 1

Holds genetic information which codes for polypeptides (proteins)

Question 2

What is the basic function of RNA?

Answer 2

Transfers genetic information from DNA to ribosomes

Question 3

Which two molecules make ribosomes?

Answer 3

RNA and proteins

Question 4

What are the differences between DNA nucleotides and RNA nucleotides?

Answer 4

In DNA the pentose sugar is deoxyribose, In RNA the pentose sugar is ribose.
In DNA the base can be thymine, in RNA the base can be uracil

Question 5

How do nucleotides join together to form polynucleotides?

Answer 5

Condensation reaction, removing water molecule
Between phosphate of one nucleotide and deoxyribose/ribose of another
Forming phosopodeister bonds

Question 6

Which bases go together?

Answer 6

AT
CG

Question 7

Describe the structure of DNA

Answer 7

Polymer of nucleotides (polynucleotide)
Each nucleotide is formed from deoxyribose, phosphate group and a nitrogen containing organic base
Phosphodiester bonds join adjacent nucleotides
2 polynucleotide chains are held together by H bonds
Between specific complementary base pairs - AT and CG
Double helix

Question 8

Describe the structure of mRNA

Answer 8

Polymer of nucleotides (polynucleotide)
Each nucleotide formed from ribose, a phosphate group and a nitrogen containing organic base
Bases are U A C G
Phosphodiester bonds join adjacent nucleotides
Single helix

Question 9

Compare the structure of DNA and mRNA

Answer 9

DNA pentose sugar is deoxyribose
DNA base is thymine
DNA is double stranded/double helix
DNA is long (many nucleotides)
DNA has H bonds/base pairings
RNA pentose sugar is ribose
RNA base is uracil
RNA is single stranded/single helix
RNA is shorter (fewer nucleotides)
RNA doesn’t have base pairings

Question 10

How do the structures of DNA relate to its functions?

Answer 10

Two strands - both act as templates for semi conservative replication
Weak H bonds between bases - strands can be separated for replication
Complementary base pairing - accurate replication
Many H bonds between bases - strong/stable molecule
Double helix with sugar phosphate backbone - protects bases/H bonds
Long molecule - store lots of genetic information that codes for polypeptides
Double helix coiled - compact