Lecture 2 - Macromolecules Flashcards
What are the 4 macromolecules?
- 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
What is a fatty acid?
a carboxylic acid with an aliphatic chain (no rings). Either saturated or unsaturated (missing hydrogens)
What is a triacylglycerol made of?
one glycerol molecule and three fatty acids
What are phospholipids made of?
- a hydrophilic head containing a phosphate group
- two hydrophobic tails derived from fatty acids
What are polysaccharides?
long-chain polymeric carbohydrates composed of monosaccharide units bound together by glycosidic bonds
What are disaccharides?
two monosaccharides joined by a glycosidic bond
What functions do polysaccharides have?
they function as storage or structural molecules
- ex starch, glycogen, cellulose, chitin
What makes up an amino acid?
an organic molecule with both an amino group and a carboxyl group
What are the 4 levels of protein structure?
- Primary Structure: linear sequence of amino acids as encoded by the DNA
- Secondary Structure: regions stabilized by hydrogen bonds between the polypeptide backbone. Alpha helices and beta-strands are the main secondary structures
- Tertiary Structure: overall shape of a polypeptide resulting from interactions between the various amino acids
- Quaternary Structure: overall structure that results from the aggregation of more than one polypeptide subunit
What are the polymers and monomers of nucleic acids called?
monomers: nucleotides
polymers: polynucleotides
What is a nucleotide made of?
- nitrogenous base
- 5-C sugar
- 1 phosphate group
What are the two families of nitrogenous bases?
pyrimidines and purines
What joins nucleotides (bond)?
a phosphodiester bond
What is at the 5’ end of DNA, the 3’ end?
5’ end -> phosphate group
3’ end -> a sugar
Transcription & Translation
Transcription: RNA polymerase uses DNA as a template to produce pre-mRNA
Translation: a ribosome builds the protein molecule (polypeptide) from a mature mRNA
