NUCLEIC ACIDS AND RNA (BIO 4)

Nucleic Acid Components

1. phosphate group

2. five-carbon sugar

3. nitrogenous base

Two groups of nitrogenous Bases

1. Purines (AG, contain nine atoms in their two rings)

2. Pyrimidines (CUT, six atoms in their one ring)

how do they bond to eachother?

Phosphodiester linkage between phosphate group and -OH, polymerization via condensation reaction between nucleic acids (adds two P groups, making nucleoside triphosphates)

DNA vs RNA

primary- ATGC vs AUGC

secondary- bases held by H bonds, Helix held by hydrophobic interactions vs. single strand folded onto itself, H bonds on same strand

tertiary- wired tightly or loosely to form supercoils vs more complex shapes of secondary structure

Histones

DNA binding proteins where supercoils wrap around

DNA Replication

1. two strands are seperated by breaking H bond

2. free deoxyribonucleotides form new H bonds with a complimentary strand

3. template and complimentary strand do base pairing

Ribozymes

RNA’s catalyze reactions, have active sites