Lec 17 Transcription

Question 1

Gene expression
Central dogma

Answer 1

gene->transcription->RNA->translation->protein

Question 2

Gene expression
what is the chemical structure of RNA

Answer 2

ribose instead of deoxyribose
U instead of T; U pairs with A

Question 3

Gene expression
how does transcription follows the base pairing rule

Answer 3

read and derive the complementary sequence
only one strand of the DNA is used

Question 4

Gene expression
what are the terms of the DNA strands

Answer 4

template strand= antisense (or - strand)
coding strand= sense (or + strand)

Question 5

Gene expression
what are the types of RNA and there function
mRNA
rRNA
tRNA

Answer 5

all single-stranded, have secondary structures
mRNA- code for proteins made by
rRNA- form part of the structure of ribosome
tRNA- carry amino acids for protein synthesis

Question 6

Gene expression in prokaryotes
what is it RNA polymerase (or RNA pol)

Answer 6

two α subunits bind regulatory proteins
β subunit binds RNA nucleoside
β’ subunit binds DNA template
σ binds promoter

Question 7

Gene expression in prokaryotes
what is the start and stop of transcription

Answer 7

promoters; -35 & -10 sequences
terminator: a stretch of FC that forms into a hairpin structure
multiple imitators
both DNA strands could be coding strands

Question 8

Transcription in eukaryotes
what are the three RNA polymerases

Answer 8

RNA pol 1: for rRNA
RNA pol 2: for mRNA and small nuclear RNA
RNA pol 3: for tRNA and small RNA

Question 9

Transcription in eukaryotes
Transcription factors- TF2 families for example

Answer 9

first TF2D complex containing TBP (TATA-box binding protein) binds to the promoter
joined by TF2B, then TF2E and others. the last factor is TF2H
TF2H phosphorylates RNA polymerase 2 and initates transcription

Question 10

transcription in eukaryotes
what is monocistronic

Answer 10

one mRNA for one peptide

Question 11

Transcription in eukaryotes
RNA modifications (only in eukaryotes)

Answer 11

5’ cap (7-mthylguanosine, 5’-5; triphosphate bridge)
3’ poly-A tail (150-250 As)
splicing

Question 12

what is splicing in transcription in eukaryotes

Answer 12

conserved splicing sequences
spliceosome contains small nuclear RNA and proteins (snRNP)
intermediate structure called lariat

Question 13

what is alternative splicing in transcription in eukaryotes

Answer 13

combinations of different exons from the same primary RNA to generate tissue specific version of proteins

Question 14

Explain the central dogma of gene expression

Answer 14

Question 15

What is the ends of amino acid

Answer 15

H2N—COOH

Question 16

coding strand is which strand

Answer 16

sense strand
(+) strand

Question 17

template strand is which strand

Answer 17

antisense strand (-)

Question 18

if given this example what what you do to transcript

Answer 18

Question 19

mRNA function (messenger RNA)

Answer 19

code for proteins

Question 20

rRNA function (ribosomal RNA)

Answer 20

form the core of the ribosome and catalyze protein synthesis

Question 21

miRNA (micro RNA) function

Answer 21

regulate gene expression

Question 22

tRNA (transfer RNA) function

Answer 22

serve as adaptors between mRNA and amino acids during protein synthesis

Question 23

snRNA (other small RNA) function

Answer 23

used in RNA splicing, telomere maintenance, and many other prcoesses

Question 24

RNA Polymerase in Prokaryotes
what is the four big things about it

Answer 24

binds to promoter of genes
able to unwind DNA, starts transcription without primer
only transcribes one of two DNA strands
adds ribonucleotides to the growing 3’ end of an RNA chain

Question 25

what are the 5 subunits in RNA polymerase

Answer 25

a(alpha) x2 binds regulatory proteins b(beta) binds RNA nucleoside subuits b’(beta) binds DNA template s(sigma) binds promoter

Question 26

what are the 5 subunits in RNA polymerase

Answer 26

a(alpha) x2 binds regulatory proteins b(beta) binds RNA nucleoside subunits b’(beta) binds DNA template s(sigma) binds promoter

Question 27

explain structure of RNA polymerase

Answer 27

Question 28

Transcription in Prokaryotes explain promoter

Answer 28

The process starts at RNA polymerase binding sites called promoters on DNA template strand. RNA polymerase begins to unwind DNA helix.

Question 29

Explain promoter and RNA polymerase

Answer 29

Question 30

Transcription in Eukaryotes How does eukaryotic transcription differ from prokaryotic transcription: (4)

Answer 30

3 RNA polymerase enzymes initiation complex forms at promoter and enhancers RNA are modified after transcription One mRNA makes one type of protein (monocistronic)

Question 31

what is monocistronic and is it in pro or euk?

Answer 31

one mRNA makes one type of protein and its in transcription of eukaryotes

Question 32

RNA polymerase 1

Answer 32

most rRNA genes

Question 33

RNA polymerase 2

Answer 33

protein-coding genes, miRNA genes, plus genes for some small RNA

Question 34

RNA polymerase 3

Answer 34

tRNA genes 5S rRNA gene genes for many other small RNA

Question 35

what are splicesome

Answer 35

splicing is carried out by splicesome which contain snRNA and snRNP

Question 36

Splicing: Intron and Exons take out which one to join __

Answer 36

take out intron and join exon