Biomolecules (Nucleic acids)

All nucleotides consist of:

• Sugar, at least 1 phosphate group, nitrogenous base

• Sugar, at least 2 phosphate groups, nitrogenous base

• Sugar, at least 3 phosphate groups, nitrogenous base

Ribose and deoxyribose differ by the presence or absence of an OH group on carbon _.

• 1

• 2

• 3

• 5

Cytosine, thymine and uracil are __________containing 1 ring.

The bonds formed between nucleotides are called:

• Ether bonds

• Glycosidic bonds

• Peptide bonds

• Phosphodiester bonds

Using the labelled structures given, draw the structure of a nucleotide.

In the boxes given, label the direction of each DNA strand in the diagram.

The ratio of purines to pyrimidines in DNA is always 1:1

True or False?

• True

• False

The ratio of adenine to cytosine in DNA is 1:1

True or False?

• True, as the ratio of purines to pyrimidines is 1:1

• True, as adenine pairs with cytosine

• False, as adenine pairs with thymine

• False, as both adenine and cytosine are purines

Which of the following is NOT true?

The structure of DNA is stabilised by:

• Hydrogen bonds between stacked bases

• Hydrogen bonds between complementary bases

• Phosphodiester bonds between adjacent nucleotides

• Hydrophobic interactions between stacked bases

Among the three types of RNA, only mRNA and tRNA are needed for the process of protein synthesis.

True or False?

• True

• False