NUCLEIC ACIDS

Nucleic Acids

are linear polymers built from individual units called nucleotide connected by bonds called phosphodiester linkages. DNA and RNA are used to store and pass genetic information from generation to the next.

nucleoside

Each nucleotide consists of a nitrogenous base, a pentose sugar, and one more phosphate groups. The portion of a nucleotide without the phosphate group is called a __

Purines

consist of two fused ring structures. Both DNA and RNA have two types of purines.

Helix

the __ consists of two strands running in an anti-parallel fashion. They are held together by a variety of interaction, including hydrogen bonds.

non-polar nitrogenous bases

the inside of the helix consists of the _

negatively-charged phosphate groups

the exterior portion of the helix contains __.

Function of DNA

1. Store genetic information that can be accessed by the organism and used to build proteins.

2. Pass down genetic information to offspring.

Function of RNA

1. Transcribe the information stored in DNA into a form that can be understood and read by the cell.

2.Assist in the protein synthesis process.

Phosphodiester bond

A — occurs when two of the hydroxyl groups in phosphoric acid react with hydroxyl groups on other molecules to form two ester bonds.

3'-to-5' phosphodiester linkages

The sugars of nucleic acids are connected by __

Nucleotides

The monomer unit of nucleic acids are _

Phosphate ester linkages

Nucleotides are connected by __

phosphate and sugar

The backbone of nucleic acids consist of alternating __ units

base sequence

The __ contains the encoded genetic information

5'

The base sequence is always specified as __ end of the nucleic acid

Watson and Crick in 1953

The secondary structure of DNA was proposed by

Erwin Chargaff

_ noted that in DNA, the percentage of pyrimidine bases was approximately equal to the purine bases

Thymine

The mole percentage of adenine is nearly to that of __.

cytosine

The mole percentage of guanine is nearly equal to _.

Test for Phosphate

Which involves the addition ammonium molybdate with dilute nitric acid resulting in a bright yellow precipitate of ammonium phosphomolybdate

Test for Ribose

Essentially the same as the Bial's test

The Bial's reagent contains concentrated hydrochloric acid which dehydrates pentose into furfural and further reacts with orcinol and ferric chloride yielding a blue-green product.

Test for Deoxyribose

This test detects the presence of deoxyribose of DNA and will not interact with ribose in RNA. Also known as the Dische test.

Acidic conditions convert deoxyribose to a molecule that binds with diphenylamine to form a blue complex.

Murexide Test

Chemical test to identify the presence of caffeine and purine derivatives in a sample.

Reaction of KOH solution produces a yellowish-brown precipitate atter heating which indicates a positive result

Test for Pyrimidines

Produces a green coloration when sample is treated with bromine water.

The addition of barium hydroxide will turn the solution purple.