Nucleotides

Question 1

Nucleotide structure

Answer 1

• A pentose sugar (Ribose on RNA) (2deoxyribose on DNA)
• a nitrogenous base (purine and pyrimidine)
• a phosphate group

Question 2

What’s the differences and similarities between 2deoxyribose and ribose

Answer 2

• both of them are pentose sugars (have 5 carbons)

- however ribose has a hydroxide on its carbon 2 whereas 2deoxyribose only has hydrogen

Question 3

What are the the 2 types of nitrogenous bases and what are the differences between them

Answer 3

• Purine: Adenine and Guanine have two carbon/nitrogen rings
• pyrimidine: Thymine, Cytosine, Uracil, only have one carbon/nitrogen ring

Question 4

Structure and function of ATP

Answer 4

• ATP (Adenosine Triphosphate) is made of adenine, Ribose and 3 phosphate groups
• high energy bonds between the phosphate groups are hydrolysed to release 30.6kj of energy which can be used in the cell

Question 5

Why is DNA replication described as Semi-conservative

Answer 5

-When DNA replicates itself the original strand is broken apart by DNA Helicase, using the 2 original strands as a template for identical daughter strands, therefore conserving the original stand of DNA.

Question 6

how many hydrogen bonds are formed between G-C and T-A

Answer 6

• 3 hydrogen bonds are formed between guanine and cytosine

- 2 hydrogen bonds form between thymine and adenine

Question 7

what is the role of RNA

Answer 7

• role in transport of genetic information from DNA to ribosomes

Question 8

how is a phosphodiester bond formed to create a polynucleotide

Answer 8

-the phosphate group at the fifth carbon of one nucleotide forms a covalent bond with the hydroxyl group at the third carbon of the pentose sugar on the adjacent nucleotide.