Nucleic

Question 1

What are nucleic acids?

Answer 1

• Information-carrying polymers.
• They are constructed by the condensation of nucleotide monomers.

Answer 2

An individual DNA or RNA nucleotide is made up of 3 components:

• A phosphate
• A pentose sugar (monosaccharide with 5 carbons)
• A nitrogenous organic base

Question 3

What are the different pentose sugars?

Answer 3

• Ribose (RNA)
• Deoxyribose (DNA)

Question 4

What are the different bases?

Answer 4

• Adenine
• Thymine (Uracil in RNA)
• Guanine
• Cytosine

Question 5

What is the bond that links the nucleotides together?

Answer 5

Phosphodiester

Question 6

What elements are present in nucleic acid?

Answer 6

• Carbon
• Oxygen
• Hydrogen
• Phosphorus
• Nitrogen

Question 7

What is the structure of RNA?

Answer 7

• Single stranded polynucleotide chain that is relatively short
• Pentose sugar is always ribose
• The bases are either Adenine, Guanine, Cytosine or Uracil

Question 8

What is the structure of DNA?

Answer 8

• A double helix structure - made up of two polynucleotide strands
• DNA molecules are extremely long
• DNA strands are antiparallel
• The pentose sugar is always deoxyribose
• The bases are either Adenine, Thymine, Guanine or Cytosine.

Question 9

Why is DNA a stable molecule?

Answer 9

• The phosphodiester backbone protects the bases inside the double helix (which carries the genetic code) - so protected from outside chemical and physical forces.
• The bases on each strand are linked by hydrogen bonds.
• Many hydrogen bonds are strong together (but weak on their own).