Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

BIOL-L 112 Exam 3 > Gene Expression; from Gene to Protein > Flashcards

Gene Expression; from Gene to Protein Flashcards

1
Q

Gene Expression

A

he process by which DNA directs protein synthesis, includes two stages

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

The two stages of Gene Expression

A

transcription and translation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Central Dogma of Molecular Biology

A

describes the flow of information from DNA to mRNA to protein.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What does the Central Dogma state?

A

It states that genes specify the sequence of mRNA which specifies the sequence of proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

RNA is the bridge between what?

A

Genes and the proteins that they code

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Transcription

A

The synthesis of RNA using information in DNA, producing mRNA.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Translation

A

The synthesis of a polypeptide, using information in the mRNA, with ribosomes being the sites of translation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Prokaryote Transcription and Translation

A

translation of mRNA can begin before transcription has finished. Transcription & translation are coupled in prokaryotes.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Eukaryotic Transcription and Translation

A

the nuclear envelope separates transcription from translation;Transcription & translation are not coupled.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Eukaryotic RNA transcripts are …

A

modified through RNA processing to yield the finished mRNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How many amino acids are there?

A

20

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

How many nucleotide bases in DNA are there?

A

4

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is a Triplet Codon

A

A series of non-overlapping, three-nucleotide words. The words of a gene are transcribed into complementary non-overlapping three-nucleotide words of mRNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

After genes are transcribed into mRNA, what happens next?

A

These words are then translated into a chain of amino acids, forming a polypeptide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is a Template Strand?

A

During transcription, one of the two DNA strands, provides a template for ordering the sequence of complementary nucleotides in an RNA transcript.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Is the template strand always the same strand for a given gene?

A

Yes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the process called from DNA to Pre-mRNA?

A

Transcription

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the process called from Pre-mRNA to mRNA?

A

RNA Processing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the Process called from mRNA to Ribosome?

A

Translation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What comes out of a Ribosome?

A

Polypeptide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

In a Bacterial Cell; What happens from DNA to mRNA?

A

Transcription

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

In a Bacterial Cell; what happens from mRNA to Ribosome?

A

Translation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What are codons?

A

mRNA base triplets

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

During translation, the mRNA base triplets are read in what direction?

A

5’ –> 3’ Direction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is the job of the codon?

A

To specify the amino acid to be placed at the corresponding position along a polypeptide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

The genetic code is ___

A

Redundant ; more than one codon may specify a particular amino acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Of the 64 triplets, how many codes are for amino acids?

A

61 Codes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Of the 64 triplets, how many codes are for “stop” signals to end translation

A

3 (UAA, UGA, UAG)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Of the 64 triplets, how many codes are TO START CODON?

A

1; AUG

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Where is non-universal genetic code located?

A

Found in the Mitochondria and Protists

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What are the three stages of transcription?

A

Initiation, Elongation, Termination

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What is RNA Polymerase

A

RNA synthesis is catalyzed by this, which pries the DNA strands apart and joins together the RNA nucleotides.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What is a Promoter

A

The DNA sequence that RNA polymerase attaches to

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What is a transcription unit?

A

The stretch of DNA that is transcribed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Does RNA Polymerase need a Primer??

A

No

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

How do Promoters start the process?

A

signal the transcriptional start point and usually extend several dozen nucleotide pairs upstream of the start point

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What are Transcription Factors?

A

They mediate the binding of RNA polymerase and the initiation of transcription.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

What is a Transcription Initiation Complex?

A

The completed assembly of transcription factors and RNA polymerase II bound to a promoter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What is a TATA box?

A

A promoter, that is crucial in forming the initiation complex in eukaryotes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

As RNA polymerase move along the DNA, how many does it untwist?

A

10-20 bases at a time

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

Transcription progresses at a rate of..

A

40 nucleotides/sec in eukkaryotes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

Which end are Nuceotides added to?

A

They are added to the 3’ end

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

Termination of Transcription; Bacteria

A

the polymerase stops transcription at the end of the terminator and the mRNA can be translated without further modification

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

Termination of Transcription; Ekaryotes

A

RNA polymerase II transcribes the polyadenylation signal sequence; the RNA transcript is released 10–35 nucleotides past this polyadenylation sequence

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

When do enzymes in the eukaryotic nucleus modify pre-mrna?

A

Before the genetic messages are dispatched to the cytoplasm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

During RNA processing, what is usually altered?

A

Both ends of the primary transcript

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

Usually, what sections are cut out and the remaining spliced together?

A

Introns are cut out, and exons are spliced together

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

Pre-mRNA molecule is modified with the 5’ and 3’ end recieving what?

A

The 5’ end receives a modified nucleotide 5’ cap (Guanine) and the 3’ gets a poly-A tail

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

Why do both the 5’ and 3’ get modified?

A

They seem to facilitate the export of mRNA to the cytoplasm
They protect mRNA from hydrolytic enzymes
They help ribosomes attach to the 5′ end

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

What are Introns?

A

They are noncoding regions; where NA transcripts have long noncoding stretches of nucleotides that lie between coding regions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

What are Exons?

A

They are eventually expressed, usually translated into amino acid sequences

52
Q

What does RNA cutting & splicing do?

A

removes introns and joins exons, creating an mRNA molecule with a continuous coding sequence

53
Q

In some cases, what is RNA splicing carried out by?

A

Spliceosomes

54
Q

What are spliceosomes

A

consist of a variety of proteins and several small nuclear ribonucleoproteins (snRNPs) that recognize the splice sites.

55
Q

What are Ribozymes?

A

are catalytic RNA molecules that function as enzymes & can splice RNA.

56
Q

Property of RNA that enables it to function as an enzyme (1)

A

It can form a three-dimensional structure because of its ability to base-pair with itself

57
Q

Property of RNA that enables it to function as an enzyme (2)

A

Some bases in RNA contain functional groupsthat may participate in catalysis

58
Q

Property of RNA that enables it to function as an enzyme (3)

A

RNA may hydrogen-bond with other nucleicacid molecules

59
Q

Importance of Introns?

A

Some introns contain sequences that may regulate gene expression
Some genes can encode more than one kind of polypeptide, depending on which segments are treated as exons during ,splicing, also known as alternative RNA splicing

60
Q

What are domains?

A

Proteins often have a modular architecture consisting of discrete regions

61
Q

Why might exon shuffling happen?

A

As a result in the evolution of new proteins

62
Q

Information and Translation

A

Genetic information flows from mRNA to protein through Translation

63
Q

How does cell translate an mRNA message into a protein’?

A

With the help of transfer RNA (tRNA)

64
Q

tRNAs transfer what?

A

Transfer amino acids to the growing polypeptide in a ribosome

65
Q

tRNA carries___

A

one specific amino acid on one end

66
Q

On the other end of a tRNA, there is…

A

an anticodon. The anticodon base-pairs with a complementary codon on mRNA

67
Q

tRNA consists of a single RNA strand that is how long?

A

80 nucleotides long

68
Q

What does a tRNA look like?

A

A cloverleaf

69
Q

Translation requires how many steps?

A

Two

70
Q

Translation Step 1

A

a correct match between a tRNA & an amino acid, done by the enzyme aminoacyl-tRNA synthetase

71
Q

Translation Step 2

A

a correct match between the tRNA anticodon & an mRNA codon

72
Q

What is a wobble?

A

Flexible pairing at the third base of a codon that allows some tRNAs to bind to more than one codon

73
Q

Ribosomes facilitate specific coupling of

A

tRNA anticodons with mRNA codons in protein synthesis

74
Q

Two ribosomal subunits are made of

A

ribosomal proteins (~ 80) and ribosomal RNAs (18S, 5S, 5.8S, 28S)

75
Q

Ribosome has how many binding sites for tRNA?

A

Three

76
Q

What are the three binding sites that a ribosome has for tRNA?

A

P, A, and E site

77
Q

P Site

A

holds the tRNA that carries the growing polypeptide chain

78
Q

A Site

A

holds the tRNA that carries the next amino acid to be added to the chain

79
Q

E Site

A

is the exit site, where discharged tRNAs leave the ribosome

80
Q

Three stages of Translation?

A

Initation, Elongation, Termination

81
Q

Translation ; Initation brings together..

A

mRNA, a tRNA with the first amino acid, and the two ribosomal subunits

82
Q

What happens first in Initation in Translation?

A

a small ribosomal subunit binds with mRNA and a special initiator tRNA (met) Then the small subunit moves along the mRNA until it reaches the start codon (AUG)

83
Q

Proteins called initation factors bring…

A

in the large subunit that completes the translation initiation complex

84
Q

Translation; During Elongation..

A

amino acids are added oneby one to the C-terminus of the growing chain

85
Q

Translation; Elongation; Each addition invovles proteins called

A

elongation factors and occurs in 3 steps: codon recognition, peptide bond formation, and translocation

86
Q

When does energy expenditure occur in Elongation (Translation?

A

During Codon Recognition and Translocation

87
Q

Translation proceeds along the mRNA in a

A

5’ –> 3’ direction

88
Q

Termination; Translation

A

Occurs when a stop codon in the mRNA reaches the A site of the ribosome

89
Q

(Termination; Translation) A site accepts..

A

A protein called a release factor

90
Q

(Termination; Translation) Release factor causes..

A

the addition of a water molecule instead of an amino acid

91
Q

(Termination; Translation) The release factor reaction

A

releases the polypeptide, and the translation assembly comes apart

92
Q

IS translation suffcient to make a functional protein?

A

Often times no

93
Q

Polypeptide chains are modified after..

A

translation or targeted to specific sites in the cell

94
Q

Post-Translational Modification, During Synthesis, polypeptide chain begins to..

A

coil & fold spontaneously to form a protein with a specific 3-D/4-D structure

95
Q

Post-Translational Modifications may be required before…

A

the protein can begin doing its particular job in the cell

96
Q

What two populations of ribosomes are evident in cells?

A

Free Ribosomes (Cytosol) and Bound Ribosomes (Attached to ER)

97
Q

Free ribosomes mostly..

A

synthesize proteins that function in the cytosol

98
Q

Bound ribosomes make..

A

proteins of the endomembrane system and proteins that are secreted from the cell

99
Q

Ribosomes are identical and..

A

can switch from free to bound

100
Q

Where does polypeptide synthesis always begin?

A

In the cytosol

101
Q

Synthesis finishes in ___ unless _______

A

the cytosol unless the polypeptide signals the ribosome to attach to the ER

102
Q

Polypeptides are destined for

A

the ER or for secretion are marked by a signal peptide

103
Q

A Signal-Recognition Particle (SRP)

A

binds to the signal peptide

104
Q

SRP brings…

A

the signal peptide and its ribosome to the ER

105
Q

Polypeptide Formation (1)

A

Polypeptide synthesis begins

106
Q

Polypeptide Formation (2)

A

SRP bings to signal peptide

107
Q

Polypeptide Formation (3)

A

SRP binds to receptor protein

108
Q

Polypeptide Formation (4)

A

SRP detaches and polypeptide synthesis resumes

109
Q

Polypeptide Formation (5)

A

Signal-cleaving enzyme cuts off signal peptide

110
Q

Polypeptide Formation (6)

A

Completed polypeptide folds into final conformation

111
Q

How is a polyribosome (or polysome) formed?

A

Multiple ribosomes can translate a singla mRNA simultaneously to form this

112
Q

Polyribosomes enable a cell to..

A

make many copies of a polypeptide very quickly

113
Q

A bacterial cell ensures astreamlined process by…

A

coupling transcription and translation

114
Q

What are mutations?

A

changes in the genetic material of a cell or virus

115
Q

What are point mutations?

A

chemical changes in just 1 base pair of a gene

116
Q

Change in a single nucleotide in a DNA template strand can lead to..

A

PRoduction of an abnormal protein (sickle cell anemia)

117
Q

Two categories of Point Mutations

A

Nucleotide-Pair Substitutions

One or more nucleotide-pair insertions or deletions

118
Q

Nucleotide-Pair Substitution

A

replaces one nucleotide and its partner with another pair of nucleotides

119
Q

Silent Mutations

A

have no effect on the amino acid produced by a codon because of redundancy in the genetic code

120
Q

Missense Mutations

A

still code for an amino acid, but not the correct amino acid

121
Q

Nonsense Mutations

A

change an amino acid codon into a stop codon, nearly always leading to a nonfunctional protein

122
Q

What are insertions and deletions?

A

Are additions or losses of nucleotide pairs in a gene

123
Q

Frameshift Mutation

A

Result after the Insertion or deletion of nucleotides may alter the reading frame,

124
Q

What are Mutagens?

A

Physical or chemical agents that can cause mutations

125
Q

Structural Gene

A

a region of DNA that can be expressed to produce a final functional product (part of a physical structure within cell) that is either a polypeptide or an RNA molecule (rRNA, tRNA).

126
Q

Regulatory Gene

A

regulates the expression of one or more structural genes by regulating the production of a protein which regulates the rate of transcription.

BIOL-L 112 Exam 3 (4 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions