DNA and RNA (2.5)

Question 1

Describe the structure of a DNA mononucleotide

Answer 1

a DNA mononucleotide contains a phosphate group, a pentose sugar (deoxyribose) and nitrogenous base.

Question 2

Describe how DNA mononucleotides join
together to form a DNA polymer/strand

Answer 2

DNA moninucleotides undergo a condensation reaction by which a sugar-phosphate bond is formed between the deoxyribose of one nucleotide and the phosphate group of another nucelotide.

Question 3

Describe the structure of a RNA mononucleotide

Answer 3

Similar to a DNA mononucleotide, an RNA nucleotide consists of a phosphate group, and pentose sugar (ribose in this case) and a nitrogenous base consisting of adenine, guanine, cytosine and uracil (not thymine as that’s only DNA.

Question 4

Describe how RNA mononucleotides join
together to form a RNA polymer/strand

Answer 4

RNA mononucleotides join together by a condensation reaction, similar to DNA mononucleotides, where a sugar-phosphate bond is formed between the ribose sugar and the phosphate group of another nucleotide.

Question 5

Describe how DNA forms a double helix

Answer 5

Each molecule of DNA is a double helix formed fromtwo complementary strands of nucleotides held together by hydrogen bonds between G-C and A-T base pairs.