Exam 3 Vocab

Deoxyribonucleic acid (DNA) and ribonucleic acid (RNA)

long linear polymers called nucleic acids that are well suited to function as carriers of genetic information

nucleic acids

carry information in a form that can be passed from one generation to the next

the sequence of the bases constitutes a form of linear information

bases are unique

sugar and phosphates are the same

central dogma

the flow of genetic information from DNA to RNA to proteins

Steps:

1) DNA replication

2) Transcription

3) Translation

nucleotide

each monomer unit within the polymer

consists of a sugar, a phosphate, and one of four bases

a nucleoside joined to 1+ phosphoryl group

ribose

the 5 carbon sugar in RNA

the 2’-carbon atom of the sugar is linked to hydroxyl (-OH) group

• makes it more reactive

• hydroxyl group acts like a nucleophile

deoxyribose

the sugar in DNA

the 2’-carbon atom of the sugar is linked to a hydrogen atom

• lacks hydroxyl group

• more stable, less reactive

• absence of 2’-OH increases resistance to hydrolysis

the backbone of DNA and RNA

consist of sugars linked by phosphodiester bridges

the 3’-OH of one sugar is esterified to a phosphate group which is joined to the 5’-OH of an adjacent sugar

consistent in a nucleic acid

each phosphodiester bridge has a negative charge

• repels nucleophilic species that can hydrolyze the backbone

the bases of DNA and RNA

bases are attacked at 1’ carbon atom of the sugar

two of the DNA bases are derivative of purines = adenine (A) and guanine (G)

two of the DNA bases are derivatives of pyrimidines = cytosine (C) and thymine (T)

RNA contains the pyrimidine derivative uracil (U) instead of thymine (T)

purines

bases that contains two fused rings

pyrimidine

bases with one ring

why is size important when discussing base pairing?

preserves the distance between bases for the double helix

nucleoside

a unit consisting of a base bonded to a sugar

why are DNA molecules long?