BCHM-3050 Lecture Notes - Lecture 3: Random Coil, Streptococcus Pneumoniae, Semiconservative Replication
Chapter 4: Nucleic Acids
Nucleobases of RNA
ď‚·Cytosine (C)
ď‚·Guanine (G)
ď‚·Adenine (A)
ď‚·Uracil (U)
Nucleobases of DNA
ď‚·Cytosine (C)
ď‚·Adenine (A)
ď‚·Guanine (G)
ď‚·Thymine (T)
Nucleic Acid Monomers - Sugar
ď‚·Ribose is a pentose that forms a heterocyclic ring but has more than just the carbons on
the ring, there is also an oxygen.
Deoxyribose is virtually identical, but there is no OH on the 2’ carbon position.
Nucleic Acid Monomers – Nucleobase
ď‚·A nucleobase is attached to the #1 carbon position of every ribose/deoxyribose sugar in a
nucleic acid.
oPurine =7 carbons & 2 rings
oPyrimidines = 6 carbons and 1 ring
ď‚·Each base is formed from either a pruine or a pyrimidine, and is heterocyclic, aromatic,
and planar.
Adenine
ď‚·Used as an energy currency for ATP & NAD(P)H and FADH2.
Guanine
The 6’ carbon is a carbonyl group and the 2’ carbon is an amino group, and they each
have 3 H+ bonds.
Thymine
ď‚·Thymine dimers are caused by exposure to UV light and are responsible for skin cancers
Uracil
ď‚·Primary function is to replace thymine in RNA
Cytosine
ď‚·Capable of making 3 H+ bonds
Methylation at the 5’ carbon – could play a role in transcriptional regulation
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Document Summary
Ribose is a pentose that forms a heterocyclic ring but has more than just the carbons on the ring, there is also an oxygen. Deoxyribose is virtually identical, but there is no oh on the 2" carbon position. A nucleobase is attached to the #1 carbon position of every ribose/deoxyribose sugar in a nucleic acid: purine =7 carbons & 2 rings, pyrimidines = 6 carbons and 1 ring. Each base is formed from either a pruine or a pyrimidine, and is heterocyclic, aromatic, and planar. Used as an energy currency for atp & nad(p)h and fadh2. The 6" carbon is a carbonyl group and the 2" carbon is an amino group, and they each have 3 h+ bonds. Thymine dimers are caused by exposure to uv light and are responsible for skin cancers. Primary function is to replace thymine in rna. Methylation at the 5" carbon could play a role in transcriptional regulation.