Brainscape's Knowledge GenomeTM

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


See full index

Biochemistry > The Central Dogma Theory > Flashcards

The Central Dogma Theory Flashcards

1
Q

What does DNA use as an intermediate for protein synthesis?

A

RNA

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

What is the process of synthesizing an RNA molecule from DNA template that will dictate the synthesis of a protein?

A

Transcription

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

Where does transcription take place?

A

Cell nucleus

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

What are the 3 general regions found in all genes?

A

1.) Promotor region
2.) Coding region
3.) Terminator region

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

What does the promotor region of a gene contain?

A

The consensus sequence

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

What happens in the coding region of a gene?

A

It is transcribed into mRNA. Transcription begins.

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

What happens in the terminator region?

A

It specified the end of transcription.

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

What is the template strand?

A

The strand of DNA that is transcribed into RNA.

AKA anti-sense strand

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

What is the template strand’s complimentary partner?

A

The non-template strand

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

What is the main key enzyme for transcription?

A

RNA polymerase

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

What does RNA polymerase do?

A

Moves along the DNA, unwinding the DNA helix just ahead of the active site for polymerization.

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

RNA polymerase catalyzes a new ____________ bond on the newly forming strand of RNA

A

Phosphodiester

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

In which direction does RNA polymerase work in?

A

5’ –> 3’

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

At what rate does RNA polymerase make mistakes? What about DNA polymerase?

A

1 for every 10^4 nucleotides

1 for every 10^7 nucleotides

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

What are the 4 steps of DNA transcription?

A

1.) Initiation
2.) Elongation
3.) Processing
4.) Termination

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

What helps the RNA polymerase recognize where to start?

A

Initiation factors

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

In prokaryotes what is the initiation factor?

A

Sigma factor

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

In eukaryotes, what is an important general transcription factor?

A

TFII

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

In step A of initiation, TFII recognized and binds a __________________ in the promotor region.

A

Consensus sequence

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

What is the TATA box?

A

A specific DNA sequence found in the promoter region of genes that plays a pivotal role in transcription initiation by serving as a binding site.

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

What is the TFII that is specific to the TATA box?

A

TFIID

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

What happens during steps B-D of initiation?

A

B. Other transcription factors join
C. RNA polymerase II joins
D. Transcription initiation complex is complete and transcription can begin

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

What are 2 other binding sites on DNA that influence initiation of transcription, other than TATA box?

A

1.) Repressor proteins bind upstream sequences called silencers (aka negative regulatory elements) **They inhibit gene transcription
2.) Transcriptional activator proteins bind upstream are called enhancers (aka positive regulatory elements)
**Increase the rate of transcription by attracting RNA polymerase II enzyme

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

During elongation, and RNA polymerase begins transcribing DNA, what happens?

A

Most general transcription factors (TFII) are released.

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

What happens to the transcription factors when they are released?

A

They are available to initiate another round of transcription with new RNA polymerase molecule

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

________ moves downstream along the DNA, transcribing the coding region.

A

RNA polymerase

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

Various ____________ factors are needed to help reduce the likelihood that RNA polymerase dissociating from DNA before it reaches the end of the gene

A

Elongation

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

What helps the RNA polymerase navigate the chromatin structure?

A

Chromatin remodeling complexes.

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

What partially disassembles & reassembles nucleosomes as an RNA Polymerase passes through?

A

Histone chaperones

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

As DNA polymerase moves along the DNA double helix it generates ___________.

A

Supercoils

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

In eukaryotes ________________________ removes super-helical tension.

A

DNA topoisomerase

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

How does DNA topoisomerase relieve super-helical tension?

A

By breaking the phosphodiester bond

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q
A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

In what 3 mains ways in the pre-mRNA transcript processed?

A

1.) Splicing
2.) Capping the 5’ end
3.) Polyadenylation of 3’ end

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

Once all pre-mRNA processing is complete, what is the transcript called?

A

mRNA

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

What is added to the 5’ end of the transcribed pre-mRNA for the 7-methyl guanosine cap?

A

A modified guanine nucleotide

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

Does the capping at the 5’ end occur early or late?

A

Early, once ~25 nucleotides of RNA have been transcribed

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

The 5’ cap facilitates export of the mRNA into the ________ and is also involved in ______________.

A

Nucleus/translation

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

Both ______ and ________ sequences are transcribed into __________.

A

intron, exon, RNA

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

Introns are then removed in a process called ____________.

A

RNA splicing

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

What is splicing performed by?

A

Spliceosomes

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

Spliceosomes require a special form of RNA _______ and proteins complexed into _________.

A

snRNA (small nuclear RNA), snRNP (small nuclear ribonucleoprotein)

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

___________ is referred to a spliceosome once it has complexed with the pre-mRNA.

A

snRNP

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

Splicing allows the same gene to produce a variety of different _______________.

A

Proteins

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

95% of human genes are _______ in more than one way.

A

Spliced

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

During step 4, the 3’ end of the mRNA molecule is specified by signals encoded in ______.

A

DNA

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

Once signals are transcribed into RNA and then bind to proteins. What do these proteins facilitate?

A

The cleavage of mRNA from RNA polymerase

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

What do Poly A tails (Poly- A Polymerase (PAP) do for the mRNA?

A

Protect it from degradation and facilitates export from the nucleus

48
Q

True or False. The steps of transcription in prokaryotes are the same as in eukaryotes.

A

True

49
Q

In what ways is the mRNA transcript produced in prokaryotes different from eukaryotes? (3)

A

1.) No processing is required for the prokaryotic mRNA (no 5’ cap, splicing, or poly-A tail)
2.) No export from nucleus (thus translation can begin right away)
3.) mRNA transcript is polycistronic (codes for more than one protein)

50
Q

What does polycistronic mean?

A

Codes for more than one protein

51
Q

Mature mRNA is exported from the nucleus through ___________.

A

Nuclear pore complexes

52
Q

The mRNA sequence is decoded in sets of how many nucleotides? What are they called?

A

3, codons

52
Q

Once in the cytosol, what is the mature mRNA translated into?

A

Protein

53
Q

How many possible combinations of 3 nucleotides are there?

A

64

54
Q

Since mRNA is interpreted in 3-nucleotide codons, the correct polypeptide sequence depends on what?

A

The correct reading frame

55
Q

What are the 3 molecules needed for translation?

A

1.) mRNA transcript
2.) tRNA (bound to the correct AA-“charged tRNA)
3.) Ribosomes (a large and small subunit)

56
Q

True or false. The cell makes a variety of tRNAs, each corresponding to all of the 20 amino acids.

A

False. Each corresponding to one of the 20 AA

57
Q

Which enzyme catalyzes the attachment of correct amino acid to tRNA?

A

aminoacyl-tRNA synthetase

58
Q

What molecule is protein synthesis performed by?

A

Ribosome

59
Q

What helps maintain correct reading frame and ensure accuracy of codon - anticodon interaction?

A

Ribosomes

60
Q

What is the ribosome complex composed of?

A

Various ribosomal proteins and ribosomal RNA (rRNA)

61
Q

What are the 2 subunits of the ribosomal complex?

A

Small ribosomal subunit (SSU) and large ribosomal subunit (LSU)

62
Q

Translation is divided into what 3 steps?

A

1.) Initiation
2.) Elongation
3.) Termination

63
Q

What are the 4 substeps involved in the elongation step of translation?

A

1.) tRNA binding
2.) Peptide bond formation
3.) Large subunit translocation
4.) Small subunit translocation

64
Q

What is the first codon translated on the mRNA?

A

AUG

65
Q

AUG is the codon for which AA?

A

Methionine

66
Q

Where is methionine always the first AA in all newly made proteins?

A

At their N-terminus

67
Q

What side of the mRNA does the small ribosome bind to?

A

The 5’ end

68
Q

True or False.
The 5’ 7-methyl guanosine cap helps with recognition of the 5’ end

A

True

69
Q

How does the scanning mechanism in initiation work? What form of energy does this require?

A

The small ribosome moves along the mRNA (from 5’ to 3’) scanning for the first AUG.

ATP hydrolysis

70
Q

When do the large ribosomal subunits assemble to complete the ribosome complex?

A

After the initiation factors dissociate

71
Q

What is the ribosome-binding site called in prokaryotes?

A

Shine-Dalgnaro sequence

72
Q

What are the 4 steps of elongation?

A

A.) tRNA binding
B.) Peptide bond formation
C.) Translocation of large subunit
D.) Translocation of small subunit

73
Q

In elongation, where does the newly charged tRNA bind to?

A

The A site of the ribosome complex

74
Q

The __________end of the polypeptide chain is released from the tRNA at the _____ site & joins the AA linked to the tRNA at the A site.

A

Carboxyl end, P site

75
Q

When the polypeptide chain goes from the p site to the a site, what enzyme catalyzes this?

A

Peptidyl transferase

76
Q

What are the different functions of the small ribosomal subunit compared to the large ribosomal subunit?

A

The small ribosomal subunit is responsible for finding and attaching to the messenger RNA (the finder)

The large ribosomal subunit plays a crucial role in the actual process of protein synthesis (the builder)

77
Q

Elongation factors enter and leave the ribosome during each cycle & are coupled with _______________.

A

GTP hydrolysis

78
Q

A ______ codon marks the end of tranlation. What are the 3?

A

Stop/ UAA, UAG, UGA

79
Q

What binds to ribosomes with a stop codon in the A site?

A

Release factors

80
Q

What enzyme catalyzes the addition of a water molecule rather than AA

A

Peptidyl transferase

81
Q

Once full translated, what happens next? 3 possibilities.

A

1.) Protein is folded into specific 3-D shape

2.)May be modified in the ER.

3.)Sent to its proper cellular location

82
Q

Where does the synthesis of proteins occur?

A

On polyribosomes (or polysomes)

83
Q

True or False. Just one initiation takes place on each mRNA molecule being translated.

A

False. Multiple initiations

83
Q

True or false.
Polysomes help speed up the rate of protein synthesis

A

True

83
Q
A
84
Q

What is the structural unit for DNA packaging?

A

nucleosome

85
Q

_________ are highly dynamic structures regulated by a host of nuclear proteins.

A

histones

86
Q

_________ can reposition nucleosomes on DNA to either expose or obscure gene regulatory elements

A

Chromatin remodeling complexes

87
Q

__________ can carry out histone modification such as methylation, acetylation, or phosphorylation.

A

Chromatin writer complexes

88
Q

Which step of protein synthesis are histones a part of?

A

transcript regulation

89
Q

What are the 2 types of histone modification?

A

1.) Histone acetylation tends to open chromatin & increase transcription
2.) Histones and DNA can both be methylated

90
Q

What enzyme performs histone acetylation?

A

histone acetyltransferases (aka HAT)

91
Q

____________ reverses the changes made during histone acetylation and promotes chromatin condensation.

A

deacetylation

92
Q

_________ can promote transcriptional activation or repression.

A

DNA methylation (and it typically results in transcriptional silencing.

93
Q

The longer an mRNA last in the cytosol, the more protein can be made via ____________.

A

translation

94
Q

Which protein receptor brings iron into a cell?

A

transferrin

95
Q

Proteins needed for intracellular cytosolic use are translated on free __________ in the cytosol.

A

ribosomes

96
Q

Proteins destined for lysosomes, ER, cell membrane or secretion need to be directed to the ______ _______ for translation. This process is called ______________.

A

rough ER, co-translational transfer

97
Q

A signal peptide sequence is translated, which binds a signal _____ _______.

A

Signal recognition particle (SRP)

98
Q

Binding of SRP (starts/stops) translation and directs the ribosome to the RER when it binds to a SRP receptor

A

stops

99
Q

If a protein needs to be inserted into a cell membrane, it will contain a _________.

A

stop transfer sequence
When the stop transfer sequence comes into contact with the translocator, translation is paused.
Translocator will discharge the polypeptide into the phospholipid bilayer of the ER membrane.

100
Q

_________rule states that the number of purines must equal the number of pyrimidines.

A

Chargaff’s

101
Q

What forces are needed to stabilize the DNA double helix?

A
  1. H-bonds between complementary base pairs
  2. Sugar phosphate backbone
  3. Base stacking
102
Q

Nucleotides are joined together along the sugar phosphate backbone with which bond type?

A

phosphodiester bond

103
Q

Consider the negative charge between phosphate groups within the sugar phosphate backbone, what stabilizes the negative charges from repeling one another?

A

Mg2+

104
Q

_________ are the structural unit for packaging DNA

A

Nucleosomes

105
Q

Nucleosomes are composed of:
How many base pairs wrapped around a histone core

A

147 base pairs: Octamer of H2A, H2B, H3 and H4

H1 linker protein

106
Q

________ is a complex of DNA + tightly bound protein

A

chromatin

107
Q

Chromatin can be found either as densely packed __________ or dispersed _______________

A

heterochromatin/euchromatin

108
Q

In it’s most condensed form, DNA is packaged into ___________

A

chromosomes

109
Q

Which cell types in the human body are haploid, meaning they contain how many copies of each chromosome?

A

sperm cells in males and egg cells (ova) in females

110
Q

Autosomal chromosomes are chromosomes 1 to ____ and they form _________ pairs

A

22/homologous

111
Q

What is the name of the non-coding sequence removed during splicing?

A

intron

112
Q

________ is a segment of DNA containing the instructions for making a particular protein

A

gene

113
Q

________= coding sequence of a gene
_________ = non-coding sequences of a gene

A

exon
intron

114
Q

98.5% of the human genome (does/ does not) encode protein

A

does NOT

115
Q
A

Biochemistry (14 decks)

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