DNA and RNA

Question 1

What are the essential roles of DNA

Answer 1

• Contains genetic material for development and function of organisms
• Has hereditary material - used to pass on genetic material to offspring

Question 2

Describe the structure of DNA

Answer 2

It is a polymer made up of nucleotide polymers

Question 3

What is a mono nucleotide

Answer 3

A molecule that is composed of a pentose sugar, a phosphate group and an nitrogen containing organic base. Monomer unit of nucleic acids

Question 4

What is a nucleotide made up of

Answer 4

• pentose sugar (5 carbons)
• Phosphate group (Contains phosphate ion)
• Nitrogenous base

Question 5

What is the pentose sugar in DNA

Answer 5

Deoxyribose

Question 6

What are the 4 organic bases in DNA

Answer 6

Guanine, Adenine, Cytosine, Thymine

Question 7

What are the 2 types of organic bases found in nucleotides

Answer 7

• Purine bases (guanine and adenine)

- Pyrimidine bases (cytosine and thymine)

Question 8

What are purine bases

Answer 8

Bases with 2 carbon rings (guanine and adenine)

Question 9

What are pyrimidine bases

Answer 9

Bases with only 1 carbon ring (cytosine and thymine)

Question 10

How are 2 mono nucleotides joined

Answer 10

Condensation reaction

Question 11

Where does the condensation reaction occur between 2 nucleotides

Answer 11

At the hydroxyl groups on the phosphate group and pentose sugar

Question 12

What bond forms between 2 mono nucleotides

Answer 12

Phosphodiester bond which forms and molecule of water

Question 13

What is a polynucleotide

Answer 13

A polymer made up of many nucleotide monomers joined by a series of condensation reactions

Question 14

What part of mono nucleotide is negative

Answer 14

Phosphate

Question 15

What part of mono nucleotide is positive

Answer 15

Nitrogenous base

Question 16

How is a dinucleotide broken into 2 mono nucleotides

Answer 16

Hydrolyses which requires water

Question 17

How are the 2 polynucleotide strands held together in DNA

Answer 17

Hydrogen bonds between the 2 bases

Question 18

How do the correct bases always pair up (A to T and G to C)

Answer 18

• A and T can form 2 hydrogen bonds, where as G and C can form 3 hydrogen bonds
• Purine bases (big) (A and G) try and can only pair with a pyrimidine base (small) (T and C) due to their sizes

Question 19

In what direction do the 2 polynucleotide strands in DNA run

Answer 19

In opposite directions to each other (antiparallel) 5 prime to 3 prime and 3 prime to 5 prime

Question 20

What are the roles of RNA

Answer 20

• Acts as a messenger molecule so helps transfer info from DNA to proteins
• ## Helps regulation and synthesis of proteins

Question 21

How is RNA similar to DNA

Answer 21

It is also a polynucleotide

Question 22

How is RNA different to DNA

Answer 22

• RNA is single stranded but DNA is double stranded
• RNA polynucleotide chains are shorter than DNA chains
• Pentose sugar in RNA is ribose and is deoxyribose in DNA
• Nitrogenous bases are GCAU (uracil)