Lecture 13 (part two of chapter 15)

Question 1

What RNA polymerase transcribes rRNA?

Answer 1

Pol I

Question 2

Eukaryotes have ____ RNA polymerases

Answer 2

three

Question 3

What RNA polmerase transcribes mRNA and some snRNA?

Answer 3

pol II

Question 4

What RNA polymerase transcribes tRNA and some other small RNAs?

Answer 4

pol III

Question 5

Each RNA polymerase recognizes its own _____

Answer 5

promoter

Question 6

RNA Pol I promoters are _____ specific

Answer 6

species

Question 7

RNA Pol II promoters consist of a ____ _______ that can be composed of a number of elements

Answer 7

core promoter

Question 8

T or F: The TATA box is included in the core promoter

Answer 8

True

Question 9

Where RNA Pol III promoters found?

Answer 9

within the gene itself

Question 10

Where is the initiation of transcription at?

Answer 10

Pol II promoters

Question 11

T or F: RNA pol II requires a series of transcription factors

Answer 11

True

Question 12

What are elongation complex factors coordinated by structural features called?

Answer 12

carboxyl terminal domain (CTD)

Question 13

In eukaryotes, the primary transcript must be modified to become ______ mRNA

Answer 13

mature

Question 14

How is the primary transcript modified to become mature mRNA?

Answer 14

-addition of 5’ cap
-addition of a 3’ poly-A tail
-removal of introns

Question 15

Why is the addition of a 5’ cap extremely important?

Answer 15

it provides RNA stabiity

Question 16

What is the process called where GTP is added to 5’ end, with GTP modified by addition of methyl group, called methyl-G cap

Answer 16

addition of a 5’ cap

Question 17

What is the 3’poly-A tail created by?

Answer 17

poly-A polymerase

Question 18

Many eukaryotic genes contain sequences that are ____ represented in mRNA

Answer 18

not

Question 19

What are the non-coding sequences called?

Answer 19

introns

Question 20

What are the sequences that will be translated called?

Answer 20

exons

Question 21

Eukaryotic cells deal with introns by cutting and putting back together the _____ ______ to produce _____ mRNA

Answer 21

primary transcript, mature

Question 22

What is the putting back together the primary transcript to produce mRNA called?

Answer 22

pre-mRNA splicing

Question 23

What particles recognize the intron-exon boundaries?

Answer 23

small ribonucleoprotein particles

Question 24

snRNPs cluster with other proteins to form _______

Answer 24

spliceosome

Question 25

What structure is responsible for removing introns via splicing?

Answer 25

spliceosome

Question 26

T or F: there is no observed rule governing the number of introns per gene, or the size of introns and exons

Answer 26

True

Question 27

What theory explains the presence of introns by suggesting exons are functional domains and intron-exon arrangements represent shuffling of those domains over evolutionary timescale?

Answer 27

exon shuffling

Question 28

What is all the RNAs produced from a genome called?

Answer 28

transciptome

Question 29

What are all the proteins produced from a genome called?

Answer 29

proteome

Question 30

T or F: the ratio of genes o transcripts to proteins is 1:1:1

Answer 30

FALSE

Question 31

What process is of a single primary transcript being spliced into different mRNAs by including different sets of exons being spliced into different mRNAs by including different sets of exons

Answer 31

alternative splicing

Question 32

What process can account for deviation from balanced ratio?

Answer 32

alternative splicing

Question 33

What process can greatly increases the number and variety of proteins encoded in the cell nucleus without increasing the size of the genome?

Answer 33

alternative splicing

Question 34

What is a key macromolecular machine involved in translation that requires interaction with mRNA and tRNA to synthesize proteins

Answer 34

Ribosomes

Question 35

What adds amino acids to the acceptor stem of tRNA?

Answer 35

aminoacyl-tRNA

Question 36

What contains three nucleotides complementary to mRNA codons?

Answer 36

anticodon loop

Question 37

What is the 2d structure of tRNA called?

Answer 37

cloverleaf

Question 38

At what prime is the acceptor end in tRNA?

Answer 38

3'

Question 39

each aminoacyl-tRNA synthetase recognizes only ___ amino acid but ____ tRNAs

Answer 39

one, several

Question 40

What type of RNA has an amino added via a charging reaction using the energy from ATP

Answer 40

charge tRNA

Question 41

What RNA is an activated intermediate molecule that can undergo peptide bond formation spontaneously

Answer 41

charged tRNA

Question 42

Acceptor stem is joined to ______ _______

Answer 42

carboxyl terminus

Question 43

What does it mean when the acceptor stem is joined to carboxyl terminus?

Answer 43

new peptide bonds are formed between amino group and carboxyl group of linked amino acids

Question 44

T or F: ribosomes do verify amino acid attached to tRNA

Answer 44

False

Question 45

What two subunits do ribosomes have?

Answer 45

large and small

Question 46

What tRNA-binding site binds the tRNA carrying the next amino acid

Answer 46

A (aminoacyl) site

Question 47

What are the three tRNA-binding sites?

Answer 47

A,P,E

Question 48

What tRNA binding site binds the tRNA attached to the growing peptide chain?

Answer 48

P (peptidyl) site

Question 49

What tRNA-binding sire binds the tRNA that carried the previous amino acid added?

Answer 49

E (exit) site

Question 50

What are the two primary functions of ribosomes?

Answer 50

1. decode the mRNA 2. form peptide bonds

Question 51

What subunit of the ribosome decodes the mRNA

Answer 51

primarily small subunit

Question 52

What is the enzymatic component of the ribosome?

Answer 52

peptidyl transferase

Question 53

What subunit is peptidyl transferase part of?

Answer 53

the large subunit

Question 54

What does the peptidyl transferase do?

Answer 54

it forms peptide bonds between amino acids

Question 55

Is the activity of ribosomes mostly thought to be carried out by rRNA or the protein component?

Answer 55

rRNA

Question 56

What complex is made up of 1. initiator tRNA charged with N-formylmethionine 2.small ribosomal subunit 3. mRNA strand

Answer 56

initiation complex

Question 57

What sequence of mRNA positions the small subunit correctly

Answer 57

Ribosome binding sequence (RBS)

Question 58

Once the components in the initiation complex are joined what is added to it?

Answer 58

the large subunit

Question 59

What site is the initiator tRNA bound to?

Answer 59

The P site

Question 60

What site is typically left empty?

Answer 60

the A site

Question 61

How is initiations in eukaryotes different than prokaryotes?

Answer 61

1.the initiating amino acid is methionine 2.more complicated initiation complex 3. Lack of an RBS

Question 62

What do eukaryotes have instead of an RBS?

Answer 62

small subunit binds to 5'cap of mRNA

Question 63

What phase adds amino acids?

Answer 63

elongation

Question 64

the ____ charged tRNA can bind to empty A site

Answer 64

2nd

Question 65

In order for elongation to add amino acids it requires a what?

Answer 65

an elongation factor

Question 66

What is the elongation factor called that binds to tRNA and GTP?

Answer 66

EF-Tu

Question 67

After the 2nd charged tRNA binds to the empty A site what can then form?

Answer 67

the peptide bond

Question 68

The addition of successive amino acids occurs as a ____

Answer 68

cycle

Question 69

What is the successive amino acid cycle?

Answer 69

1. matching tRNA anitcodon with mRNA codon 2. peptide bond formation 3. translocation of ribosomes

Question 70

T or F: in wobble pairing there are more tRNAs than codons

Answer 70

FALSE

Question 71

What type of pairing allows for less stringent pairing between the 3' base of the codon and the 5' base of the anticodon?

Answer 71

wobble pairing

Question 72

T or F: Wobble pairing allows a lower number of tRNAs to accommodate all codons

Answer 72

True

Question 73

Elongation continues until the ribosome encounters a ____ codon

Answer 73

stop

Question 74

Stop codons do not bind to ______

Answer 74

tRNA

Question 75

What factors recognize stop codons?

Answer 75

release factors

Question 76

What do release factors do?

Answer 76

they release the polypeptide from the ribosome

Question 77

Where in Eukaryotes can translation occur?

Answer 77

in the cytoplasm or the rough endoplasmic reticulum (RER)

Question 78

What sequence is at the beginning of the polypeptide sequence bind to the signal recognition particle in the cytoplasm?

Answer 78

signal sequence

Question 79

What recognizes the signal sequence and the SRP complex?

Answer 79

RER receptor proteins

Question 80

What holds ribosome to RER?

Answer 80

docking

Question 81

______ is the beginning of the protein-trafficking pathway

Answer 81

protein targeting

Question 82

What is defined as the heritable change in the genetic material?

Answer 82

mutations

Question 83

A ______ mutation leads to single-nucleotide variation in populations

Answer 83

point

Question 84

What is the substitution of one base for another called?

Answer 84

base substitution

Question 85

What are the two categories of base subsitution?

Answer 85

1. transition 2. transversion

Question 86

What type of base substitution is where a purine- purine or pyrimidine-pyrimidine is mutated?

Answer 86

transition

Question 87

What type of base substitution mutation is where a purine-pyrimidine or vice versa is mutated?

Answer 87

transversion

Question 88

What are the three classes of point mutations?

Answer 88

1. silent 2. missense 3. nonsense

Question 89

What type of class of a point mutation is when the same amino acid is inserted, essentially no net effect?

Answer 89

silent mutation

Question 90

What type of class of a point mutation is where it changed the amino acid inserted?

Answer 90

missense mutation

Question 91

What type of class of point mutation is where it changed to a stop codon?

Answer 91

nonsense

Question 92

The gain or loss of 1 to 50 bp is called an ______

Answer 92

insertion/ deletion

Question 93

What characteristics do frameshift mutations have?

Answer 93

1. addition or deletion of a base 2. much more profound consequences 3. they alter the reading frame downstream

Question 94

mutations are the starting point for ______

Answer 94

evolution

Question 95

Human mutation rates can now be measured directly via _____ ______ of parents and their childern

Answer 95

whole-genome sequencing