Chapter 5: Organic Molecules of Life (Nucleic Acids)

Genetic Code

Nucleotide triplets of DNA and RNA molecules that carry genetic information in living cells

What are the 2 major types of nucleic acids?

Deoxyribonucleic acid (DNA) and Ribonucleic acid (RNA)

Give an overview of gene expression

Gene along a DNA creates a mRNA molecule → the mRNA interacts with a ribosome to create a polypeptide chain → primary structure protein

What is the monomer and polymer of nucleic acids?

Monomer → nucleotide

Polymer → nucleic acid

How are nucleotides made?

Nitrogenous base, Pentose sugar, 1 or more Phosphate groups

Nucleosides

Monomers with nitrogenous base and pentose sugar, but no phosphate group of nucleotides

What are the 2 types of nitrogenous bases?

Pyrimidines → 1 single six-membered ring

Purines → 2 rings (1 six-membered and 1 five-membered)

What are the bonds between nucleotides called?

Phospho-diester bonds

What bonds together in a phospho-diester bond?

Phosphate of one sugar and an hydroxyl group of another sugar

Sugar-Phosphate Backbone

A repeating pattern of sugar-phosphate-sugar-phosphate

What is the importance of a sugar-phosphate backbone?

It stabilizes the structure of each individual DNA strand

What is the difference between RNA and DNA in terms of construction and bases?

Construction → ribose instead of pentose sugar

Base → uracil instead of thymine

What does it mean for a DNA strand to be antiparallel?

The two strands of a DNA run side-by-side but point in opposite directions

What does transfer RNA (tRNA) do with the mRNA?

tRNA matches the codons read on the mRNA

What determines the 5' and 3' end of a DNA strand?

5′ end → attached to a phosphate group

3′ end → carries a hydroxyl (-OH) group

Human Genome Project

Goal was to map and sequence all the base pairs of the complete human genetic blueprint and identify the genes contained within it

Human Proteome Project

Goal is to map and characterize every protein encoded by the human genome