Biochem exam 3

Question 1

Topoisomerase type 2 inhibitors

Answer 1

doxorubicin (adriamycin)
etoposide (etopopos)
Ellepticine

Question 2

Topoisomerase type 1 inhibitors

Answer 2

Captothecin
Irinotecan (campto)
Topotecan (hycamtin)

Question 3

RNA Polymerase 1

Answer 3

transcription of major ribsomal RNA genes

Question 4

RNA Polymerase 2

Answer 4

transcription of protein-coding genes and some small RNA genes
-Has a carboxy terminal domain with highly conserved repeats
-Binds to TATA binding protein, TFII A, B, E, F, H

Question 5

RNA Polymerase 3

Answer 5

Transcription of small RNA genes

Question 6

Primary transcript

Answer 6

unprocessed newly synthesis RNA molecule

Question 7

Processing of mRNA

Answer 7

splicing out introns and joining exons for continous sequence
-Adding a 5’ cap
-Adding a 3’ cap
-Degration

Question 8

5’cap

Answer 8

7-methylguanosine link at 5’5 -triphosphate link and protect the RNA from nucleases
-forms binding site for ribosomes

Question 9

exons

Answer 9

coding regions they can be translated

Question 10

introns

Answer 10

non coding regions they are transcribe but not translated

Question 11

group 1 and group 2 introns

Answer 11

self splicing no required additional protein of ATP
-in nucleus, mitochondria and chloroplast

Question 12

Spliceosomal introns

Answer 12

they are splice by spliceosomes
the most common introns
usually in protein coding regions in eukaryotes genomes

Question 13

tRNA introns

Answer 13

they are spliced by protein based enzymes

Question 14

primary trascript is cleaved

Answer 14

by endonuclease

Question 15

mRNA

Answer 15

messenger RNA encode the AA sequence of all polypeptide found in the cell

Question 16

exons are joined

Answer 16

by ATP dependent ligase

Question 17

Alternative splicing

Answer 17

a single gene can yield different peptides depending on the RNA processing
-Particular region can be removed or retained, yielding different mature transcripts

Question 18

tRNA

Answer 18

transfer RNA they match their anticodon to the mRNA while carrying the specific AA for protein synthesis

Question 21

rRNA

Answer 21

ribosomal RNA they encode code large and small ribosomal subunits

Question 22

ribozymes

Answer 22

catalytic RNA molecule act as enzymes

Question 23

miRNA

Answer 23

microRNA they function is gene regulation
-Short non coding RNA of 22 nucleotides
-bind to specific regions in the mRNA and alter translation
they are synthesized by large precursors
they are proccessed by two riboendonucleases= Drosha and Dicer

Question 24

ribonucleases

Answer 24

degradation of mRNA

Question 25

gag

Answer 25

group associated antigen -encodes for long polypeptide that is then cleave into 6 smaller proteins

Question 26

pol

Answer 26

polypeptide they code for protease that cleaves the long polypeptides, reverse transcriptase, integrase to insert the DNA into the host DNA

Question 27

env

Answer 27

encodes viral enveloped

Question 28

LTR

Answer 28

long terminal repeats facilitates incorporation of the virus genome to the host DNA

Question 29

-nucleoside or nucleotide analogous dine or sine -zidovudine (AZT) -didanosine (videx)

Answer 29

reverse transcriptase inhibitors drugs

Question 30

idinavir, saquinavir

Answer 30

protease inhibitors -since protease are use to cleave proteins for packing into new viral particles

Question 31

p-independent

Answer 31

UUU in the 3' end of transcript RNA polymerase will stop and dissociate the mRNA

Question 32

p-dependent

Answer 32

CA rich sequence called a rut site -p protein helicase is proccess until termination is reached -p-protein helicase will bind to the rut site and separate the mRNA from the DNA template