Genetics exam 3 Flashcards
where is the hydroxyl group on RNA located?
2’ carbon of its sugar
what direction does RNA synthesize?
5’-3’
Ribosomal RNA
structural and functional components of ribosome
messenger RNA
carries genetic code for proteins
transfer RNA
helps incorporate amino acids into polypeptide chain
small nuclear RNA
processing and assembly of rRNA
small nucleolar RNA
processing of pre-mRNA
microRNA
inhibits translation of mRNA
small interfering RNA
triggers degradation of other RNA molecules
piwi-interacting RNA
suppresses the transcription of transposable elements in reproductive cells
CRISPR RNA
assists destruction of foreign DNA
long noncoding RNA
eukaryotic nucleus and cytoplasm variety of functions
what is gene collinearity?
continuous sequence of nucleotides in DNA encodes a continuous sequence of amino acids in a protein
what is gene non-collinearity?
discovered by hybridizing DNA with mRNA transcribed from it, nucleotides in a gene and amino acids in a protein should be proportional
what is an intron?
removed from pre-RNA by RNA splicing
what are the components of mature mRNA?
5’ untranslated region, protein-coding region, 3’ untranslated region
what are different pre-mRNA modifications?
addition of 5’ cap, 3’ cleavage and addition of poly (A) tail, RNA splicing, RNA editing
addition of 5’ cap
facilitates binding of ribosome to 5’ end of mRNA, increases mRNA stability, enhances RNA splicing
3’ cleavage and addition of poly(A) tail
increases stability of mRNA, facilitates binding of ribosome to mRNA
RNA splicing
removes noncoding introns from pre-mRNA, facilitates export of mRNA to cytoplasm, allows for multiple proteins to be produced through alternative splicing
RNA editing
alters nucleotide sequence of mRNA
what is the function of the consensus sequence?
determines where splicing were occur, exists at the 5’ and 3’ splice sites and upstream of the 3’ splice site in pre-mRNAs
what is the process of splicing
cleavage at 5’ splice site, cleavage of 3’ splice site, intron removal
what are the function of spliceosomes?
large macromolecular structures containing a set of snRNPs formed from snRNAs and many proteins
