RNA #12

Question 1

non canonical bases are more common in RNA or DNA?

Answer 1

in RNA, like dihydrouracil and pseudouracil and hypoxantine

Question 2

inosine pairs with which bases?

Answer 2

adenine, thymine, cytosine

Question 3

which has more molecular species RNA or DNA?

Answer 3

RNA

Question 4

which type of RNA is most unstable?

Answer 4

mRNA

Question 5

self splicing introns are ?

Answer 5

ribozymes

Question 6

what is the function of RNase P

Answer 6

it is a ribonuclease involved in tRNA maturation

Question 7

family tree of RNA

Answer 7

~total RNA can be divided into: coding (2-4%) and noncoding (96-98%)
~coding RNA becomes mRNA
~non coding RNA : tRNA (15%), rRNA (80%), and in eukaryotes (snoRNA, scRNA, snRNA)

Question 8

house keeping RNA are?

Answer 8

tRNA, rRNA, snRNA

Question 9

Molecular heterogeneity?

Answer 9

the # of molecules refers to the # of molecular species. NOT TO THE ACTUAL # OF MOLECULES

Question 10

function of rRNA

Answer 10

constitute ribosomes and provide the peptidyle transferase activity (catalyse protein synthesis)

Question 11

function of tRNA

Answer 11

has a central role in protein synthesis acting as adapters between mRNA and aa

Question 12

function of snRNA

Answer 12

splicing reaction of pre-mRNA

Question 13

function of snoRNA

Answer 13

are used to process and chemically modify rRNA

Question 14

function of scaRNA

Answer 14

used to modify snRNA and snoRNA

Question 15

Function of miRNA

Answer 15

regulate gene expression by interfering with translation and destabilizing mRNA

Question 16

function of siRNA

Answer 16

turn off gene expression by directing degradation of specific mRNA

Question 17

Svedberg Units

Answer 17

is a sedimentation coefficient, the heavier a structure is the more its sedimentation coefficient. Note that these coefficients are not additive

Question 18

what code do all tRNA have at the acceptor stem?

Answer 18

5’- CCA- 3’. this is where the aa bonds

Question 19

how to tRNA move along a rRNA unit

Answer 19

go from the A site to the P site to the E site