2.6 DNA & RNA STRUCTURE

Question 1

Nucleic acid

Answer 1

very large molecules that are constructed by linking together nucleotides to form a polymer

Question 2

two types of nucleic acid

Answer 2

1. DNA (deoxyribonucleic acid) is a more stable double stranded form that stores the genetic blueprint for cells
2. RNA (ribonucleic acid) is a more versatile single stranded form that transfers the genetic information for decoding

Question 3

differences between DNA and RNA

Answer 3

1. Type of pentose sugar - DNA is deoxyribose and RNA is ribose. Deoxyribose has one fewer oxygen atom then ribose
2. Number of strands present
3. Composition of nitrogenous bases 4 bases in DNA are adenine, cytosine, guanine and thymine.
   4 bases are adenine, cytosine, guanine and uracil

Question 4

structure of DNA

Answer 4

Each strand consists of a chain of nucleotides linked by covalent bonds

The two strands are parallel but run in opposite directions - antiparallel

The two strands are wound together to form a double helix

The strands are held together by hydrogen bonds between the nitrogenous bases (complementary base pairing)

Question 5

Crick and Wantson’s models of DNA structure