Nucleic Acids 2

Flashcards covering key concepts from a lecture on nucleic acids, including DNA and RNA structure, properties, and replication.

Nucleic Acids

The biochemistry of DNA and RNA.

Polynucleotides

Covalent bonds formed via phosphodiester linkages, resulting in a negatively charged backbone.

DNA backbone

Fairly stable; hydrolysis accelerated by enzymes (DNAses).

RNA backbone

Unstable; mRNA is degraded in cells in a few hours.

Linear polymers

No branching or cross-links.

Directionality of Polynucleotides

The 5’ end is different from the 3’ end, and the sequence is read from 5’ to 3’.

Hydrolysis of RNA

RNA is unstable under alkaline conditions; hydrolysis is also catalyzed by enzymes (RNase).

S-RNase

Prevents inbreeding in plants.

RNase P

A ribozyme that processes tRNA precursors.

Dicer

An enzyme that cleaves double-stranded RNA into oligonucleotides for protection from viral genomes and RNA interference technology.

Hydrogen-Bonding Interactions

Two bases can hydrogen bond to form a base pair; Watson-Crick base pairs predominate in double-stranded DNA (A pairs with T, C pairs with G).

Watson-Crick base pairs

A pairs with T.

Watson-Crick base pairs

C pairs with G.

Discovery of DNA Structure

Watson and Crick's discovery of DNA structure, highlighting its novel features and biological significance.

Complementarity of DNA Strands

Two chains differ in sequence (sequence is read from 5’ to 3’), are complementary, and run antiparallel.

Replication of Genetic Code

Strand separation occurs first, each strand serves as a template for the synthesis of a new strand, catalyzed by DNA polymerases, resulting in one daughter strand and one parent strand.