How Do genes Direct the Production of Proteins

Question 1

Cells achieve their specialized functions based upon (2)

Answer 1

the expression of specific genes and any subsequent post-translational modifications of the resulting proteins

Question 2

DNA is — into RNA, which is — into Protein

Answer 2

transcribed

translated

Question 3

in prokaryotes, when do transcription and translation occur?

Answer 3

simultaneously

Question 4

is DNA or RNA more stable?

Answer 4

DNA is very stable, RNA degrades quickly as pH raises

Question 5

RNA contains (2)

Answer 5

uracil

ribose sugar

Question 6

DNA contains (2)

Answer 6

thymine

deoxyribose is missing an OH group

Question 7

In both Prokaryotes and Eukaryotes only one strand of the DNA is transcribed into RNA depending upon the

Answer 7

gene

Question 8

the RNA molecule being synthesized is made in the — direction and therefore the DNA strand that is used as template is oriented —

Answer 8

5’ to 3’

3’ to 5’

Question 9

in both Prokaryotes and Eukaryotes gene transcription can proceed in opposite directions from

Answer 9

one gene to the next

Question 10

In Prokaryotic organisms the DNA is organized in a linear or contiguous fashion and transcription of the DNA into RNA results in an RNA copy that is ready for use as a

Answer 10

template for protein synthesis (translation)

Question 11

In Prokaryotic organisms the RNA transcript can be translated into a protein during the transcription process as there is

Answer 11

no nucleus

Question 12

In Eukaryotic organisms the DNA is broken up into regions or blocks of sequence that will give rise to

Answer 12

the protein sequence (coding regions or exons)

Question 13

These exons are separated by (2)

Answer 13

regions that do not code for protein (introns) and regions at the 5’ and 3’ ends that do not encode protein called untranslated regions (UTRs)

Question 14

In Eukaryotic organisms one strand of the DNA is first copied in a linear fashion and then the introns are removed by a process called

Answer 14

splicing

Question 15

Subsequent modifications take place that give rise to the mature mRNA, which is transported out of the nucleus for use as the

Answer 15

temple for protein synthesis (translation)

Question 16

In Eukaryotic organisms primary transcripts are often spliced in multiple combinations of exons, known as

Answer 16

alternative splicing

Question 17

alternative splicing gives rise to a

Answer 17

family of possible proteins that can have slightly different functions, regulation and/or tissue specificity (i.e. different splice variants are found in different tissues)

Question 18

what is a gene?

Answer 18

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

Question 19

what regulates gene regulation? (2)

Answer 19

promoters and enhancers

Question 20

what is convolved in gene transcription (2)

Answer 20

RNA polymerase

TF

Question 21

what is involved in genes and RNA? (7)

Answer 21

axons and introns
promoter regions
start site and stop site for transcription 
UTR
splicing 
capping 
polyadenylation

Question 22

mRNA (2)

Answer 22

messenger RNA

translated into proteins

Question 23

tRNA (2)

Answer 23

transfer RNA

transfer amino acids to the growing peptide chain

Question 24

rRNA (2)

Answer 24

ribosomal RNA

encodes ribosomal proteins

Question 25

microRNA

Answer 25

Block translation of specific mRNAs and thereby regulate gene expression

Question 26

siRNA (2)

Answer 26

small interfering RNAs | turn off gene expression by directing the selective degradation of mRNAs.

Question 27

snoRNA (2)

Answer 27

small nucleolar RNAs | process and chemically modify rRNAs

Question 28

scaRNA (2)

Answer 28

small cajal RNAs | modify snoRNAs and snRNAs

Question 29

what are other noncoding RNAs involved in? (3)

Answer 29

telomere synthesis X-chromosome inactivation protein transport into the ER

Question 30

percent abundance of rRNA in a cell

Answer 30

~80%

Question 31

percent abundance of tRNA in a cell

Answer 31

~15%

Question 32

percent abundance of mRNA in a cell

Answer 32

~3-5%

Question 33

percent abundance of other RNA in a cell

Answer 33

<1%

Question 34

Most protein coding genes are transcribed by

Answer 34

RNA Polymerase II

Question 35

Transcription initiates at a specific point in the DNA and requires

Answer 35

unwinding of the DNA to create the proper single-stranded template

Question 36

Gene expression regulatory proteins recognize specific DNA sequences and upon binding regulate

Answer 36

if, when and to what extent a gene is transcribed

Question 37

Gene expression is regulated by numerous transcription factors that interact with

Answer 37

promoter elements in DNA and/or proteins bound to those promoter elements

Question 38

The presence/absence of specific factors is an obligatory first step in the initiation of

Answer 38

TBP/TFIID binding and subsequent RNA Polymerase binding

Question 39

what does TBP TF2D bind to

Answer 39

TATA sequence

Question 40

what does TF2B bind to?

Answer 40

TF2D/TATA

Question 41

helices activity

Answer 41

unwind DNA

Question 42

RNA is not just a --- molecule

Answer 42

linear

Question 43

TF2D subunits (2)

Answer 43

TBP | TAF

Question 44

TBP subunit

Answer 44

recognizes TATA box

Question 45

TAF subunit

Answer 45

recognizes other DNA sequences near the transcription start point, regulates DNA binding by TBP

Question 46

TF2B

Answer 46

recognizes BRE element in promoters; accurately positions RNA polymerase at the start site of transcription

Question 47

RNA polymerase 1 transcribes (3)

Answer 47

5.8S, 18S, and 28S rRNA genes

Question 48

RNA polymerase 2 transcribes (5)

Answer 48

``` all protein coding genes snoRNA genes miRNA genes siRNA genes most snRNA genes ```

Question 49

RNA polymerase 3 transcribes (4)

Answer 49

tRNA genes 5S rRNA genes some snRNA genes genes for other small RNAs

Question 50

what does "s" value refer to

Answer 50

their rate of sedimentation in an ultracentrifuge

Question 51

the larger the S value,

Answer 51

the larger the rRNA

Question 52

mRNA processing (5)

Answer 52

``` capping splicing editing polyadenylation transport ```

Question 53

RNA splicing is performed by the

Answer 53

spliceosome

Question 54

spliceosome is largely made up of

Answer 54

snRNAs in complex with 7 protein subunits to form a SNP

Question 55

snRNAs involved in splicing are (5)

Answer 55

U1, U2, U4, U5 and U6

Question 56

The snRNAs provide for

Answer 56

proper base pairing with the mRNA

Question 57

These RNA-RNA arrangements are

Answer 57

dynamic and shift throughout the splicing process

Question 58

lariat

Answer 58

associated with splicing

Question 59

Many mRNAs can be spliced in various ways to produce different combinations of exons depending upon the

Answer 59

tissue and/or the types of cell signals present/absent

Question 60

The human genome contains --- genes, but the human proteome is estimated to contain ---

Answer 60

~20,000-25,000 | ~250,000 proteins

Question 61

most heavily spliced genes

Answer 61

alpha tropomyosin gene

Question 62

different sliced forms of the alpha tropomyosin gene (5)

Answer 62

``` striated muscle mRNA smooth muscle mRNA fibroblast mRNA fibroblast mRNA brain mRNA ```

Question 63

The 5’cap and splicing of the primary mRNA transcript occur as soon as the

Answer 63

hnRNA emerges from the RNA polymerase

Question 64

The poly-A tail is added to the 3’end of the mRNA by a set of

Answer 64

RNA-binding proteins and RNA-processing enzymes as soon as it emerges from the RNA polymerase

Question 65

Mature mRNA is then exported from the nucleus through a specific export receptor mediated process involving (2)

Answer 65

nuclear bound proteins, some of which are shed during export, and cytoplasmic (ER) located initiation factors involved in protein synthesis

Question 66

miRNA (2)

Answer 66

small non-coding RNA | ~21-25 nt in length

Question 67

how does miRNA regulate translation? (3)

Answer 67

Bind to 3’UTR of target mRNA to form an RNA-inducing silencing complex (RISC) Suppress protein synthesis and/or induce mRNA degradation Each miRNA can target multiple (up to 100) different mRNAs

Question 68

what does pri-mRNA form

Answer 68

a hairpin structure

Question 69

mature mRNA is a

Answer 69

single string

Question 70

the mature mRNA can bind to the ..

Answer 70

3' UTR of target mRNA to interrupt protein synthesis

Question 71

- bases code for one amino acid

Answer 71

3

Question 72

3 base sequence is known as a

Answer 72

codon

Question 73

The genetic code is “---” for all organisms it is essentially the same

Answer 73

universal

Question 74

“commaless”

Answer 74

read from beginning to end so reading frame is critical

Question 75

Degenerate:

Answer 75

more than one codon can make the same amino acid

Question 76

The third base in the triplet codon is less --- that the first two

Answer 76

specific

Question 77

3 of the 64 possible codons do not code for amino acids, but signal ---

Answer 77

termination

Question 78

Roberts syndrome

Answer 78

Prenatal growth retardation (mild to severe), craniofacial abnormalities such as microcephaly and cleft lip/palate and limb malformations (usually limbs are short and the arms are more severely affected than legs).

Question 79

what mutation occurs with Roberts syndrome?

Answer 79

Homozygous mutation of ESCO2

Question 80

Homozygous mutation of ESCO2 encodes

Answer 80

an acetyltransferase important for the formation of the cohesion complex that binds to chromosomes and creates cohesion between sister chromatids

Question 81

Closely related to Cornelia de Lange Syndrome (mutations in Smc1, Smc3, NIPBL), collectively referred to as

Answer 81

Cohesionopathies

Question 82

Studies suggest that the ESCO2 mutations lead to decreased rDNA transcription and subsequent ribosomal biogenesis and the observed defects in

Answer 82

nucleolar morphology

Question 83

This leads to decreased

Answer 83

protein synthesis