How Genes Direct the Production of Proteins

Question 1

What is it called when DNA is turned into RNA?

Answer 1

transcription

Question 2

What is it called when RNA is turned into proteins?

Answer 2

translation

Question 3

Is DNA or RNA more stable?

Answer 3

DNA
-if you look at RNA funny it will fall apart
-only make RNA when you need proteins in the cell

Question 4

Which DNA strand is transcribed into RNA?

Answer 4

the 3’-5’ strand

Question 5

In which direction is RNA made?

Answer 5

5’-3’

Question 6

What is a gene?

Answer 6

segment of DNA that is transcribed into RNA and its associated transcriptional control regioins

Question 7

What is mRNA?

Answer 7

messenger RNA
-translated into proteins

Question 8

What is tRNA?

Answer 8

transfer RNA
-transfer AA to the growing peptide chain

Question 9

What is rRNA?

Answer 9

ribosomal RNA
-encode ribosomal proteins

Question 10

What is microRNA?

Answer 10

microRNAs
-block translation of specific mRNAs and thereby regulate gene expression

Question 11

What is siRNA?

Answer 11

small interfering RNA
-turn off gene expression by directing the selective degradation of mRNA

Question 12

What is snoRNA?

Answer 12

small nucleolar RNA
-process and chemically modify rRNA

Question 13

What is scaRNA?

Answer 13

small cajal RNAs
-modify snoRNAs and snRNAs

Question 14

What is the most abundant type of RNA?

Answer 14

rRNA (80%)

Question 15

What percentage of RNA is tRNA?

Answer 15

15%

Question 16

What percentage of RNA is mRNA?

Answer 16

3-5%

Question 17

What is responsible for the transcription of most protein coding genes?

Answer 17

RNA polymerase II

Question 18

Where do transcription factors bind to initiate transcription?

Answer 18

TATA box

Question 19

do transcription factors regulate gene expression?

Answer 19

yes

Question 20

Is RNA a linear molecule?

Answer 20

no, it associates with itself and makes secondary structures
-rory RNA cowboy

Question 21

What does the TBP do?

Answer 21

recognize TATA box
*subunit of TFIID

Question 22

What does TAF do?

Answer 22

recognize other DNA sequences near the transcription start point
*subunit of TFIID

Question 23

What does TFIIB do?

Answer 23

recognize BRE element in promoters
-accurately positions RNA polymerase at start site

Question 24

What does TFIIF do?

Answer 24

stabilizes RNA polymerase interactions with TBP and TFIIB
-helps attract TFIIE and TFIIH

Question 25

What does TFIIE do?

Answer 25

attracts and regulates TFIIH

Question 26

What does TFIIH do?

Answer 26

unwinds DNA at transcription start point

Question 27

What does RNA polymerase I transcribe?

Answer 27

rRNA genes

Question 28

What does RNA polymerase II transcribe?

Answer 28

all protein coding genes

Question 29

What does RNA polymerase III transcribe?

Answer 29

tRNA

Question 30

What is mRNA splicing ?

Answer 30

-preformed by splicesome which is largely made of snRNA complex with 7 protein subunits to form an SNP -snRNAs involved in splicing -snRNAs provide proper base pairing with mRNA*** -RNA-RNA arrangements are dynamic and shift through the splicing process***

Question 31

What does splicing do?

Answer 31

remove introns

Question 32

mutation in intron could lead to...

Answer 32

intron not being able to be spliced

Question 33

What is alternative splicing?

Answer 33

splicing mRNAs in various ways to produce different combinations of exons depending upon the tissue and/or types of cells singlas

Question 34

Characteristics of mature mRNA:

Answer 34

-spliced -5' cap (prevents it from unwinding) -poly A tail -exported from nucleus

Question 35

How do miRNAs regulate translation?

Answer 35

-bind to 3' UTR of target mRNA to form an RNA-inducing silencing complex -suppress protein synthesis and/or induce mRNA degradation -each miRNA can target multiple different mRNAs

Question 36

What is a codon?

Answer 36

three base pair sequence that codes for an amino acid

Question 37

important features of genetic code:

Answer 37

-read frame the beginning to end (reading frame is crucial) -degenerate (more than one codon can bring in the same AA) -third base in triplet codon is less specific than the first two -3 of the 64 possible codons do not code for AA, but signal termination

Question 38

what are the stop codons?

Answer 38

UAA UAG UGA

Question 39

what is the start codon?

Answer 39

AUG

Question 40

What is Roberts syndrome?

Answer 40

prenatal growth retardation, craniofacial abnormalities (microcephaly and cleft lip/palate) and limb formation -homozygous mutation of ESCO2 -decrease rRNA transcription and lead to nucleolar morphology defects -decreases protein synthesis

Question 41

How can we affect gene expression without changing genetic code?

Answer 41

epigenetics