CH4710 RM26

gene

a segment of a DNA molecule that contains the information required for the synthesis of a functional biological product, whether protein or RNA

4 classes of RNA

1. ribosomal (rRNA): components of ribosomes

2. messenger (mRNA): intermediates on protein synthesis

3. transfer (tRNA): translate info in mRNA into amino acid sequence

4. noncoding (ncRNA): wide variety of functions

3 components of nucleotides

1. nitrogenous base (pyrimidine or purine)

2. pentose

3. 1+ phosphates

nucleoside

nucleotide without phosphate group

Identify

pyrimidine

Identify

purine

bond within nucleotide

a N-beta-glycosyl bond covalently joins the 1’ carbon of pentose to the base

phosphate is bonded at 5’ carbon of pentose

pyrimidine vs purine bonding to pentose

pyrimidine bond at N-1

purine bond at N-9

nitrogenous bases, purine vs pyrimidine

purine: A and G

pyrimidine: C, T, and U

what are the structural units of DNA

deoxyribonucleotides

“deoxy-”

• adenosine

• guanosine

• thymidine

• cytidine

what are the structural units of RNA

ribonucleotides

• adenosine

• guanosine

• uridine

• cytidine

process of nucleotides carrying chemical energy

hydrolysis of nucleoside phosphates provides chemical energy (similar to ATP)

nucleotides and enzyme relationship

adenine is component of enzyme cofactors

what joins nucleotide chains in DNA and RNA

phosphodiester linkage

describe phosphodiester linkage

between 5’ phosphate of one nucleotide and the 3’ OH of the next nucleotide

why is RNA rapidly hydrolyzed and DNA is not

RNA nucleotides contain 2’ OH groups and DNA does not

OH- can attack that OH group to break phosphodiester linkage

oligonucleotide

short nucleic acid (less than 50 nucleotides)

polynucleotide

longer nucleic acid