The Structure of RNA

Question 1

Like DNA, the nucleic acid RNA (ribonucleic acid) is a poly

Answer 1

polynucleotide

Question 2

Like DNA, RNA nucleotides contain the nitrogenous bases

but it doesn’t include but contains

Answer 2

Like DNA, RNA nucleotides contain the nitrogenous bases adenine (A), guanine (G) and cytosine (C)

Unlike DNA, RNA nucleotides never contain the nitrogenous base thymine (T) – in place of this they contain the nitrogenous base uracil (U)

Question 3

Unlike DNA, RNA nucleotides contain the pentose sugar

Answer 3

ribose (instead of deoxyribose)

Question 4

Unlike DNA, RNA molecules are only made up of

Answer 4

one polynucleotide strand (they are single-stranded)

Question 5

What is the size comparison for RNA and DNA

Answer 5

RNA polynucleotide chains are relatively short compared to DNA

Question 6

Each RNA polynucleotide strand is made up of

Answer 6

alternating ribose sugars and phosphate groups linked together,

with the nitrogenous bases of each nucleotide projecting out sideways from the single-stranded RNA molecule

Question 7

he sugar-phosphate bonds (between different nucleotides in the same strand) are covalent bonds known as phosphodiester bonds

These bonds form what is known as the

Answer 7

sugar-phosphate backbone of the RNA polynucleotide strand

Question 8

The phosphodiester bonds link the

Answer 8

5-carbon of one ribose sugar molecule to the phosphate group from the same nucleotide, which is itself linked by another phosphodiester bond to the 3-carbon of the ribose sugar molecule of the next nucleotide in the strand

Question 9

An example of an RNA molecule is messenger RNA (mRNA), which is the

Answer 9

transcript copy of a gene that encodes a specific polypeptide. Two other examples are transfer RNA (tRNA) and ribosomal RNA (rRNA)

Question 10

You need to know the difference between DNA and RNA molecules (bases, number of strands, pentose sugar present, length).