Lecture 2 pt 1 Flashcards
what kind of RNA are translated
mRNA only
what percent of RNA in a cell are mRNAs
3-5%
what percent of RNA in a cell are rRNAs
75-80%
what percent of RNA in a cell are tRNAs
10-15%
what percent of RNA in a cell are all the RNAs other than mRNA, rRNA, tRNA
less than 5%
order the different RNAs in order of percentage in a cell
- most
- rRNA
- tRNA
- mRNA
- everything else
- least
the template strand is the _________ (coding/ non- coding) strand
non-coding
the non-template strand is the _________ (coding/ non- coding) strand
coding strand
RNA has the same sequence as the _______ (coding/ template) DNA strand except U instead of T (and the sugar)
coding
what follows the central dogma
- all cells
- except retroviruses and prions
what is for the permanent storage of genetic info
DNA
what is for the transient storage of genetic info
RNA
what is the final gene product
protein
when is RNA not for the transient storage of genetic info
structural and catalytic RNA
when is protein not the final gene product
when the final product is structural and catalytic RNS
what does mRNA stand for
messenger RNA
what does rRNA stand for
ribosomal RNA
what does tRNA stand for
transfer RNA
what does snRNA stand for
small nuclear RNA
what does snoRNA stand for
small nuclear RNA (same as snRNA)
what does lncRNA stand for
long noncoding RNA
what does miRNA stand for
MicroRNAs
what does siRNA stand for
small interfering RNA
what does piRNA stand for
Piwi-interacting RNA
what do mRNAs do
code for proteins
are exons normally long or short compared to introns
- exons= short
- introns= long
what is one of the central problems in producing proteins from info in genomes
- most steps depend on conventional nucleic acid base pairing
- which is only modestly accurate
what do mRNAs stand for and what do they do
- messenger RNAs
- code for proteins
what do rRNAs stand for and what do they do
- ribosomal RNAs
- form the basic structure of the ribosome and catalyze protein synthesis
what do tRNAs stand for and what do they do
- transfer RNAs
- central to protein synthesis as the adaptors between mRNA and AA
- serve as the adaptors that select amino acids and hold them in place on a ribosome for incorporation into protein
what do snRNAs stand for and what do they do
- small nuclear RNA
- function in a variety of nuclear processes,
- direct the splicing of pre-mRNA to form mRNA
what do snoRNAs stand for and what do they do
- Small nucleolar RNAs
- help to process and chemically modify rRNAs
what do lncRNAs stand for and what do they do
- Long noncoding RNAs
- not all of which appear to have a function; some serve as scaffolds and regulate diverse cell processes, including X-chromosome inactivation
what do miRNAs stand for and what do they do
- MicroRNAs
- regulate gene expression by blocking translation of specific mRNAs and causing their degradation
what do siRNAs stand for and what do they do
- Small interfering RNAs
- turn off gene expression by directing the degradation of selective mRNAs and helping to establish repressive chromatin structures
what do piRNAs stand for and what do they do
- Piwi-interacting RNAs
- bind to piwi proteins and protect the germ line from transposable elements
