Lecture 3

Question 1

What are four classes of biological macromolecules

Answer 1

Nucleic acids
Proteins
Polysaccharides
Lipids

Question 2

Basic functions of all four macromolecules

Answer 2

Nucleic acids - make up genetic information in living things
Proteins - structural, hormonal, transport, receptor
Polysaccharides - energy storage or structural support
Lipids - regulate membrane permeability

Question 3

What are the monomers for nucleic acids, proteins, polysaccharides

Answer 3

Nucleic acid = nucleotides
Proteins = amino acids
Polysaccharides = monosaccharide

Question 4

What is the building block principle for biological polymers

Answer 4

A large molecule made of repeating subunits (monomers). For example,
a carbohydrate is a polymer that is made of repeating monosaccharides.
Nucleic acids are polymers of nucleotides
– 4 different types in different combinations
Proteins are polymers of amino acids
– 20 different types in different combinations
• Polysaccharides are polymers of
monosaccharides
– Usually of only one type (e.g. glucose)

Question 5

Distinguish between pyrimidine and purine

Answer 5

The two-carbon nitrogen ring bases (adenine and guanine) are purines
while the one-carbon nitrogen ring bases (thymine and cytosine) are pyrimidines.

Question 6

Distinguish between ribose or deoxyribose

Answer 6

Ribose, found in RNA, is a “normal” sugar, with one oxygen atom attached to each carbon atom.
Deoxyribose, found in DNA, is a modified sugar, lacking one oxygen atom

Question 7

Distinguish between RNA and DNA

Answer 7

DNA is double-stranded, 
DNA contains thymine
DNA contains deoxyribose. Also, three of the nitrogenous bases are the same in the two types (adenine, cytosine, and guanine), 
RNA contains ribose as a sugar,
RNA is single-stranded. 
RNA contains uracil.