Nucleic acid: structure of DNA and RNA

Question 1

Function of DNA

Answer 1

Holds genetic information

Question 2

Function of RNA

Answer 2

transfers genetic information from DNA to ribosomes.

Question 3

What are the differences between the DNA and RNA structures

Answer 3

-DNA nucleotide has pentose sugar deoxyribose whereas RNA nucleotide has ribose
-DNA nucleotides can have thymine whereas RNA nucleotide has Uracil
-DNA molecules are double stranded whereas RNA molecules are single stranded.
-DNA is longer whereas RNA is shorter.

Question 4

How does a Phosphodiester bond form

Answer 4

Condensation reaction between 2 nucleotides

Question 5

How is DNA molecule different to RNA

Answer 5

DNA has strands joined in anti-parallel held together by H bonds between the base pairs -AT and CG

Question 6

How is the structure of DNA related to its function

Answer 6

-Large number of weak H bonds between complementary bases on different strands allow the molecule to be stable and can be unzipped for replication.
-Double helix allows for protection of bases.
-Long molecule so stores lots of genetic information
-Double stranded so allows for semi-replication of DNA as both strands act as templates
-Complementary base pairing so identical copies can be made
-double helix is coiled so its is compact.

Question 7

structure of DNA

Answer 7

Polymer of nucleotides
Each nucleotide formed from deoxyribose, a phosphate (group) and a nitrogenous base
Phosphodiester bonds (between nucleotides);
Double helix held by hydrogen bonds;
Hydrogen bonds between adenine, thymine and
cytosine, guanine