Chapter Twelve: Gene Expression at the Molecular Level

Question 1

Whose work on genetics, in the early 1900s, was rediscovered and finally understood?

Answer 1

Gregor Mendel

Question 2

What British Physician in 1908, who was studying the inheritance of the disease Alkaptonuria, proposed a link between genes and the production of enzymes?

Answer 2

Archibald Garrod

Question 3

By 1908, biochemists understood that metabolic pathways consisted of a series of…each one converting one chemical to another

Answer 3

enzymes

Question 4

Garrod applied Mendel’s theory on genes to the pathway for the breakdown of Phenylalanine and the disease…

Answer 4

Alkaptonuria

Question 5

Garrod was the first to link genes with…production

Answer 5

enzyme

Question 6

What did Garrod term defective genes?

Answer 6

Inborn Errors of Metabolism

Question 7

Garrod began the field of…

Answer 7

Human or Medical Genetics

Question 8

Beagle and Tatum saw Garrod’s work while working on the nutritional needs of a mold called…

Answer 8

Neurospora

Question 9

After Beadle and Tatum exposed the mold spores to….(to produce mutations) they isolated a number of mutant strains which could not produce certain nutrients

Answer 9

X-rays

Question 10

Beadle and Tatum were working on the inheritance or genetics of…strains

Answer 10

mutant

Question 11

The metabolic pathway for Arginine production was known to be controlled by how many enzymes?

Answer 11

three

Question 12

Beadle and Tatum found several straight of Neurospora that could not produce…

Answer 12

Arginine

Question 13

Beadle and Tatum found that different stains had different mutations which prevented…synthesis, but at different steps in the pathway

Answer 13

Arginine

Question 14

What theory was proposed by Beadle and Tatum in which each gene controls a separate enzyme?

Answer 14

One Gene, One Enzyme Theory

Question 15

One Gene, One Enzyme Theory
1. Genes control the…of enzymes, but not all genes encode enzymes

Answer 15

production

Question 16

One Gene, One Enzyme Theory
2. Not all enzymes consist of a single polypeptide. Some multimeric enzymes are formed by the product of multiple genes, each producing a separate…which combines to form the enzyme

Answer 16

polypeptide

Question 17

One Gene, One Enzyme Theory
3. some genes are alternatively…to produce multiple proteins, or versions of a protein. So some genes produce multiple proteins - 20,000 human genes produce more than 2 million proteins

Answer 17

spliced

Question 18

The “Central Dogma” of Biology: traces the path of…flow within cells

Answer 18

information

Question 19

Transcription is DNA-directed…synthesis

Answer 19

RNA

Question 20

RNA Polymerase is the one molecule that is concerned with…

Answer 20

Transcription

Question 21

What is this?
- region of gene where RNA Polymerase attaches to Transcribe gene

Answer 21

Promoter

Question 22

What are the three types of RNA?

Answer 22

mRNA
tRNA
rRNA

Question 23

Are all types of RNA transcribed the same way?

Answer 23

yes

Question 24

What type of RNA?
- carries the information from DNA to the Ribosome

Answer 24

mRNA

Question 25

What type of RNA? - a component of Ribosomes

Answer 25

rRNA

Question 26

What type of RNA? - escorts amino acids to the Ribosome

Answer 26

tRNA

Question 27

What is a precursor for Transcription?

Answer 27

Ribonucleoside Triphosphate

Question 28

Mechanism of Ribonucleoside Triphosphate: - removal of…and polymerization of…to 3’ end of growing RNA chain

Answer 28

Pyrophosphate Polymerization

Question 29

Transcription occurs on…strand only

Answer 29

template

Question 30

Transcription occurs on…gene only

Answer 30

one

Question 31

RNA Polymerase attaches to DNA and…DNA

Answer 31

denatures

Question 32

In Eukaryotes, a variety of…are involved in the attachment of RNA Polymerase and DNA

Answer 32

proteins

Question 33

Proteins involved in the attachment between RNA Polymerase and DNA are termed Initiation and…factors

Answer 33

Transcription

Question 34

What lines up opposite DNA Template stand and RNA Polymerase connects them together in the 5’ to 3’ direction?

Answer 34

Ribonucleoside Triphosphates

Question 35

Within a chromosome, different strands of the double stranded DNA form the…strand

Answer 35

template

Question 36

…occurs in a variety of ways in different RNAs. The final product (Primary Transcript), however is not the finished product

Answer 36

Termination

Question 37

…are all Post-transcriptionally modified in a variety of ways

Answer 37

RNAs

Question 38

The addition of a 5’ 7-methyl Guanosine “cap” occurs in…only

Answer 38

mRNA

Question 39

Addition of a Poly-A tail occurs in…only

Answer 39

mRNA

Question 40

Splicing: The removal of…can occur to any type of RNA, from the action of Spliceosomes, a complex of RNA and Proteins

Answer 40

Introns

Question 41

….is a complex of RNA and proteins involved in the action of splicing

Answer 41

Spliceosomes

Question 42

The removal of introns results in an RNA Transcript much…than the corresponding gene (DNA)

Answer 42

shorter

Question 43

Alternative Splicing: Not all…are included in the final mRNA

Answer 43

exons

Question 44

Alternative Splicing: If different introns are used to produce a mRNA, different proteins may be produced in different cells or tissues from the same…

Answer 44

gene

Question 45

The primary transcript may be cut into more than one…(all RNAs exhibit this modification, but it always occurs in rRNA)

Answer 45

RNA

Question 46

RNA Editing is a process by which one or more…in an RNA can be changed, added or removed

Answer 46

nucleotides

Question 47

In…editing, one nucleotide is substituted for another

Answer 47

Substitution

Question 48

In…Editing, nucleotides are added or removed

Answer 48

Insertion/Deletion

Question 49

With Substitution editing,…modify or change one bae into another

Answer 49

enzymes

Question 50

Substitution Editing: Cytidine deaminases coverts a C in the RNA to…

Answer 50

Uracil (U)

Question 51

Substitution Editing: Adenosine deaminase converts an A to Inosine (I), which the ribosome translates as a…

Answer 51

G

Question 52

Insertion/Deletion Editing uses guide RNAs produced by separate genes to bind and identify other RNA molecules in which a…will be added or removed

Answer 52

nucleotide

Question 53

Is RNA editing in all three types of RNA?

Answer 53

Yes

Question 54

Errors in RNA Editing can cause mental diseases such as…

Answer 54

schizophrenia

Question 55

The removal of nucleotides from the 5’ and/or 3’ end occurs in…RNAs

Answer 55

all

Question 56

The…modification of bases occurs in tRNA only

Answer 56

chemical

Question 57

The addition of CCA to 3’ end (if already does not end with CCA) occurs in…only

Answer 57

tRNA

Question 58

Where does this take place? - 5’ methyl-G cap

Answer 58

mRNA

Question 59

Where does this take place? - Poly-A tail

Answer 59

mRNA

Question 60

Where does this take place? - Chem. Modification of bases

Answer 60

tRNA

Question 61

Where does this take place? - Add CCA to 3’ end

Answer 61

tRNA

Question 62

Where does this take place? - Splicing

Answer 62

universal

Question 63

Where does this take place? - cut into >1 RNA

Answer 63

universal

Question 64

Where does this take place? - trimming

Answer 64

universal

Question 65

Where does this take place? - editing

Answer 65

universal

Question 66

All three RNAs are used for…

Answer 66

Translation

Question 67

All three RNAs are used for Translation: - mRNA carries the…

Answer 67

information

Question 68

All three RNAs are used for Translation: - tRNA brings the…

Answer 68

amino acids

Question 69

All three RNAs are used for Translation: -rRNA is a component of…

Answer 69

ribosomes

Question 70

What is this? - a sequence of 3 bases in mRNA which code for an Amino Acid

Answer 70

Codon

Question 71

There are three codons (…) which stops translation rather than insert an Amino Acid

Answer 71

Terminators

Question 72

The codon AUG is the…, it marks the point where Translation begins

Answer 72

Initiation Codon

Question 73

The Genetic Code is degenerate (redundant), most Amino Acids are represented by more than one…

Answer 73

Codon

Question 74

tRNA has a 2-D shape and looks like a…

Answer 74

3-leaf clover

Question 75

tRNA has an…(amino acid is attached to the 3’ end of tRNA)

Answer 75

Acceptor Stem

Question 76

tRNA has a 3-D shape in which it looks like an…

Answer 76

L

Question 77

The…Loop is across from the acceptor stem, it pairs with the codon on mRNA

Answer 77

Anticodon

Question 78

Aminoacyl-tRNA Synthtases load proper AMino Acid onto…using energy from ATP

Answer 78

tRNA

Question 79

1. Aminoacyl-tRNA Synthetase binds…and the specific Amino Acid recognized by that Activating Enzyme. The energy from ATP is transferred to the Amino Acid as AMP

Answer 79

ATP

Question 80

2. Then the Synthetase binds one of the group of tRNAs recognizing that amino acid, and the Amino Acid is transferred from the…. to the tRNA

Answer 80

AMP

Question 81

3. Finally, the tRNA, charged with the appropriate…is released, as is the Enzyme (in an unaltered state)

Answer 81

Amino Acid

Question 82

Ribosomes: structure - large and small subunits each constructed of one or more…and 20-30 proteins

Answer 82

rRNA

Question 83

Self Assembly - the parts automatically come together to form…

Answer 83

Ribosomes

Question 84

The ribosome has how many positions to hold tRNAs?

Answer 84

three

Question 85

What are the three ribosomal positions to hold tRNAs?

Answer 85

A site P site E site

Question 86

What does the A site hold?

Answer 86

new tRNA

Question 87

What does the P site hold?

Answer 87

tRNA with polypeptide chain

Question 88

What does the E site hold?

Answer 88

empty tRNA to exit the ribosome

Question 89

Translation (RNA-Directed Polypeptide Synthesis) 1. small…subunit attaches to 5’ end of mRNA

Answer 89

ribosomal

Question 90

Translation (RNA-Directed Polypeptide Synthesis): 2. first…attaches to small subunit P site. Uses GTP as an energy source

Answer 90

tRNA

Question 91

Translation (RNA-Directed Polypeptide Synthesis) 3. Large ribosomal subunit attaches to form the complete…

Answer 91

Ribosome

Question 92

Translation (RNA-Directed Polypeptide Synthesis) 4. The first Aminoacyl-tRNA has attached at the…Site and the second attaches at the…Site of the Ribosome, matching the 2nd codon of the mRNA

Answer 92

P A

Question 93

The mRNA-Ribosome-tRNA Complex positions the Amino Acids so they are…to one another

Answer 93

adjacent

Question 94

Translation (RNA-Directed Polypeptide Synthesis): 5. …catalyzes a peptide bond between the first two Amino Acids by transferring the first amino acid from the first tRNA to the second amino acid

Answer 94

Peptidyl Transferase

Question 95

Amino Acids are polymerized (connected) with the…

Answer 95

Condensation (Dehydration) Reaction

Question 96

Amino Acids are polymerized (connected) with the Condensation (Dehydration) Reaction. Results in a direct…covalent bond

Answer 96

Carbon-Nitrogen

Question 97

Translation (RNA-Directed Polypeptide Synthesis): 6. …moves the Ribosome to the next codon, using GTP as an energy source, with release of first tRNA from the exit (E) site. The first Amino Acid is attached to the second, which is attached to the second tRNA.

Answer 97

Translocation

Question 98

Translation (RNA-Directed Polypeptide Synthesis): 7. The 3rd aminoacyl-tRNA anticodon attaches to the..Site of the Ribosome according to the 3rd mRNA codon.

Answer 98

A

Question 99

Translation (RNA-Directed Polypeptide Synthesis): 8. Peptidyl Transferase catalyzes the next peptide bond. The Ribosome Translocates in the…direction once more

Answer 99

3’

Question 100

Translation (RNA-Directed Polypeptide Synthesis): 9. Repeat steps…

Answer 100

6-8

Question 101

Translation (RNA-Directed Polypeptide Synthesis): 10. Upon reaching a termination (stop) codon, a…Protein attaches instead of an Aminoacyl tRNA

Answer 101

Releasing

Question 102

The releasing factor binds to the A-Site and causes the release of the last…and the Polypeptide

Answer 102

tRNA

Question 103

The…Ribosomal Subunits are released from the mRNA and are recycled to find the same or another mRNA to Translate

Answer 103

two

Question 104

Each mRNA is…by numerous Ribosomes at the same time. Once the first clears the 5’ end, the next attaches

Answer 104

Translated

Question 105

A…is one mRNA and all the multiple Ribosomes Translating it at the same time

Answer 105

Polysome

Question 106

Once synthesized, proteins with transit sequence may be exported to various…

Answer 106

organelles

Question 107

The Role of the ER in Glycoproteins Synthesis: …causes the Ribosome to be transported to the ER

Answer 107

Signal Sequence

Question 108

When the signal sequence is completed, the…is released in the lumen of the ER and Ribosomal subunits are released to the Cytoplasm

Answer 108

Glycoprotein

Question 109

Once, synthesized, proteins may be modified in what three ways?

Answer 109

Proteolysis Glycosylation Phosphorylation