BioChem 2.6 DNA and RNA Structure

Question 1

What is the name of the structure of DNA?

Answer 1

DNA consists of many nucleotides. This is called a polynucleotide.

Question 2

How are DNA polynucleotide monomers linked?

Answer 2

DNA polynucleotide monomers are linked together by covalent bonds into single strand DNA polymers.

Question 3

Draw a labelled diagram of single DNA Nucleotide.

Answer 3

Composed of deoxyribose sugar, nitrogenous bases and phosphorus group.

Question 4

What are the 4 different nitrogenous bases for DNA?

Answer 4

A - Adenine G - Guanine T - Thymine C - Cytosine (Always go to chemistry)

Question 5

What nitrogenous base is complementary to Adenine?

Answer 5

Adenine is complementary to Thymine. Double Hydrogen Bond.

Question 6

What nitrogenous base is complementary to Cytosine?

Answer 6

Cytosine is complementary to Guanine. Triple Hydrogen Bond.

Question 7

What are the base pairing rules?

Answer 7

Adenine double bond Thymine Cytosine triple bond Guanine

Question 8

Which nitrogenous bases are Purines?

Answer 8

Adenine and Guanine are purines.

Question 9

Which nitrogenous bases are pyrimidine?

Answer 9

Thymine and Cytosine are pyrimidine.

Question 10

Draw a structure of DNA with 6 DNA nucleotides.

Answer 10

DNA strands are antiparallel to form a double helix. Include: - Sugar phosphate backbone - complementary base pairs - Hydrogen bases between bases of two strands (dotted line)

Question 11

What is the general structure of a DNA polynucleotide?

Answer 11

a DNA polynucleotide is a double stranded helix. The DNA strands are antiparallel linked by hydrogen bonds between the complementary nitrogenous base pairs.

Question 12

Describe the structure of RNA.

Answer 12

RNA is a polynucleotide. RNA nucleotide monomers are linked together by covalent bonds into single stranded DNA polymers.

Question 13

What are RNA nucleotides composed of?

Answer 13

RNA nucleotides are composed of ribose, one sugar phosphate group and a nitrogenous base.

Question 14

What are the RNA complementary base pairing rules?

Answer 14

Adenine and Uracil Cytosine and Guanine

Question 15

Draw a labelled RNA polynucleotide

Answer 15

Include sugar phosphate backbone.

Question 16

Compare the structures of DNA and RNA

Answer 16

Similarities:

• Both have sugar phosphate groups
• Both have nitrogenous bases
• Both have pentose sugars
• Both are poly nucleotides
• Both have covalent bonds
• Both have sugar phosphate backbones
• Both have Adenine and Guanine as purines
• Both store genetic information

Differences:

• DNA has deoxyribose. RNA has ribose
• DNA is a double helix and is therfore double stranded. RNA is single stranded
• DNA must have hydrogen bonds between the nitrogen bases. RNA is mainly covalently bonded and only occasionally has hydrogen bonds.
• DNA has Thymine and Cytosine as pyrimidines. RNA has Uracil and Cytosine as pyrimidines.
• DNA has an anti-parallel structure. RNA with only one strand has only one direction. 5’ to 3’