Chapter 11

Question 1

Overview of transcription and translation

Answer 1

DNA to RNA to proteins

Question 2

What is the function of mRNA

Answer 2

It is an intermediate between a gene and a polypeptide

Question 3

What are transcription enzymes?

Answer 3

RNA polymerases

Question 4

RNA polymerase moves in what direction?

Answer 4

3’ to 5’

Question 5

What do RNA polymerases do?

Answer 5

Incorporate nucleotides into an RNA strand, complementary to DNA strand

Question 6

Where is the proofreading function found?

Answer 6

In transcription

Question 7

What are operons?

Answer 7

Genes organized in clusters that are transcribed together as single mRNA molecule encoding for multiple proteins

Question 8

Where does transcription happen in eukaryotes?

Answer 8

In the nucleus

Question 9

Where do RNA processing steps happen in eukaryotes?

Answer 9

In the nucleus

Question 10

Where does translation happen in eukaryotes?

Answer 10

In the cytoplasm

Question 11

Why does translation happen in eukaryotes?

Answer 11

mRNA needs to be exported to cytoplasm

Question 12

How many types of RNA polymerases are there in eukaryotes?

Answer 12

3

Question 13

What are the three types of RNA polymerases in eukaryotes?

Answer 13

RNA pol I, II, and III

Question 14

RNA polymerase I does what?

Answer 14

Transcribed most RNAs

Question 15

RNA polymerase II does what?

Answer 15

Transcribes mRNAs

Question 16

RNA polymerase III does what?

Answer 16

Transcribed tRNAs

Question 17

Which RNA polymerases are only found in plants/

Answer 17

RNA pol IV and V

Question 18

What doe RNA pol IV and V do?

Answer 18

Transcribes siRNAs

Question 19

What are the 3 steps of transcription?

Answer 19

1) Initiation
2) Elongation
3) Termination

Question 20

What do transcription factors binds to?

Answer 20

DNA elements in upstream regulatory regions within upstream promotors and enhancers

Question 21

What forms the preinitiation complex?

Answer 21

RNA pol II and general transcription factors

Question 22

Where do general transcription factors assemble?

Answer 22

Pre-initiation complex, upstream of transcriptional start site

Question 23

What do GTF recruit?

Answer 23

RNA pol II

Question 24

What is the function of the tail and cap on DNA?

Answer 24

Protect from degradation, help export outside nucleus, and translation process

Question 25

Where are mRNAs translated?

Answer 25

On ribosomes

Question 26

What are split genes?

Answer 26

Presence of genes contain intervening sequences

Question 27

What are exons?

Answer 27

Parts of split gene that contribute to mature mRNAs

Question 28

What are introns?

Answer 28

Part of split genes that correspond to intervening sequences

Question 29

What is RNA splicing?

Answer 29

Removal of introns from a pre-RNA

Question 30

Do transcription factors regulate gene expression?

Answer 30

Yes

Question 31

A single gene can be controlled by (different, the same) regulatory proteins?

Answer 31

Different

Question 32

What does the extent to which a gene is transcribed depend on?

Answer 32

Particular combination of transcription factors bound to upstream regulatory elements

Question 33

What gives rise to phenotypes?

Answer 33

Gene expression

Question 34

What does RNA processing do?

Answer 34

Trims primary transcripts

Question 35

How many possible codons are there for 20 amino acids?

Answer 35

64

Question 36

What codon encodes for methionine?

Answer 36

AUG

Question 37

What is the starting signal of translation?

Answer 37

AUG

Question 38

What are the three codons that stop translation?

Answer 38

UAA, UGA, UAG

Question 39

What can decode the info in an mRNA?

Answer 39

tRNA

Question 40

What do all mature tRNAs have at their 3' end?

Answer 40

CCA triplet sequence

Question 41

Does it require energy to add aas to each tRNA?

Answer 41

Yes

Question 42

Translation is:

Answer 42

Protein synthesis

Question 43

What can be seen as the most complex activity of the cell?

Answer 43

Translation

Question 44

3 steps of initiation of translation?

Answer 44

1) Small subunit/AUG binding 2) Aminoacyl tRNA recruitment 3) Assemble initiation complex

Question 45

Overall process of translation

Answer 45

1) Initiation 2) Elongation 3) Elongation step 2 4) Elongation step 3 5) Elongation step 4 6) Termination

Question 46

What plays a major role in selecting tRNAs and ensuring accurate translation?

Answer 46

ribosomal RNAs

Question 47

What is the first step of elongation?

Answer 47

Aminoacyl-tRNA selection

Question 48

What is the second step of elongation?

Answer 48

Peptide bond formation between 3 aas

Question 49

What is the third step of elongation?

Answer 49

Translocation

Question 50

What is the fourth step of elongation?

Answer 50

Releasing the deacylated tRNA

Question 51

What is a polyribosome?

Answer 51

A complex of multiple ribosomes on mRNA, allowing simultaneous translation

Question 52

What do polyribosomes do to the rate of protein synthesis?

Answer 52

Increase rate of protein synthesis

Question 53

What surveillance mechanism is capable of detecting messages with premature termination?

Answer 53

mRNA surveillance mechanism