Lecture 2 - Macromolecules

Question 1

What are the 4 macromolecules?

Answer 1

• lipids: high molecular weight molecules soluble in nonpolar solvents
• proteins: comprise one or more chains of amino acid residues
• polysaccharides: long polymer chains of sugars
• nucleic acids: DNA and RNA

Question 2

What is a fatty acid?

Answer 2

a carboxylic acid with an aliphatic chain (no rings). Either saturated or unsaturated (missing hydrogens)

Question 3

What is a triacylglycerol made of?

Answer 3

one glycerol molecule and three fatty acids

Question 4

What are phospholipids made of?

Answer 4

• a hydrophilic head containing a phosphate group
• two hydrophobic tails derived from fatty acids

Question 5

What are polysaccharides?

Answer 5

long-chain polymeric carbohydrates composed of monosaccharide units bound together by glycosidic bonds

Question 6

What are disaccharides?

Answer 6

two monosaccharides joined by a glycosidic bond

Question 7

What functions do polysaccharides have?

Answer 7

they function as storage or structural molecules
- ex starch, glycogen, cellulose, chitin

Question 8

What makes up an amino acid?

Answer 8

an organic molecule with both an amino group and a carboxyl group

Question 9

What are the 4 levels of protein structure?

Answer 9

1. Primary Structure: linear sequence of amino acids as encoded by the DNA
2. Secondary Structure: regions stabilized by hydrogen bonds between the polypeptide backbone. Alpha helices and beta-strands are the main secondary structures
3. Tertiary Structure: overall shape of a polypeptide resulting from interactions between the various amino acids
4. Quaternary Structure: overall structure that results from the aggregation of more than one polypeptide subunit

Question 10

What are the polymers and monomers of nucleic acids called?

Answer 10

monomers: nucleotides
polymers: polynucleotides

Question 11

What is a nucleotide made of?

Answer 11

• nitrogenous base
• 5-C sugar
• 1 phosphate group

Question 12

What are the two families of nitrogenous bases?

Answer 12

pyrimidines and purines

Question 13

What joins nucleotides (bond)?

Answer 13

a phosphodiester bond

Question 14

What is at the 5’ end of DNA, the 3’ end?

Answer 14

5’ end -> phosphate group
3’ end -> a sugar

Question 15

Transcription & Translation

Answer 15

Transcription: RNA polymerase uses DNA as a template to produce pre-mRNA
Translation: a ribosome builds the protein molecule (polypeptide) from a mature mRNA

Question 16

What is the bond between 2 amino acids called?

Answer 16

a peptide bond