Properties of RNA Flashcards
Where is it found in Eukaryotes
Nucleus and cytoplasm
Structure
Primary– sequence of ribonucleotides from 5 to 3
Secondary– 75-94nt cloverleaf H-bonding pattern, 3 loops and a stem Amino acid adds to 3’-OH of 3’-terminal A - forms an ester bond with carboxyl group of amino acid
Anticodon 3 nt sequence that recognizes and base pairs with a particular mRNA codon (3 nt that specify a specific amino acid)
TΨC loop ribosome recognition site for binding tRNA
Tertairy–L shaped, 64 codons and 45 distinct types of tRNA
Characteristics
Absorb at 260nm
less going sequences of complementarity
less base pairs and hence lower viscosity
Uracil rather than Thymine
Cytosine deprotonates to form Uracil
conversion of C to U could result on a heritable change
Ribose rather than deoxyribose
DNA has greater resistance to alkaline hydrolysis
High pH leads to hydrolysis of phosphodiester bonds in RNA
Why have both DNA and RNA
grooves in RNA bigger than DNA allowing access to degrading enzymes making RNA less stable than DNA
ncRNAs
snRNA- process RNA transcripts
miRNA- regular amount of protein made
siRNA- genome defence
lncRNA-regulate gene expression
Introns and Exons
Introns are excised
Exons are spliced together
About secondary structure
single strand make up right handed helix with base-stacking interactions, cannot form a B-DNA type double helix as the 2’-OH groups are a steric hindrance.
