Brainscape's Knowledge GenomeTM

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


See full index

Biology 1A03 > Chapter 16: Transcription and Translation > Flashcards

Chapter 16: Transcription and Translation Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Biology flashcards Biology 101 flashcards
1
Q

What is transcription?

A

Using DNA to code for RNA molecules

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

What main molecules are required for transcription?

A
  • DNA template
  • RNA polmerase
  • rNTP (ribonucleotide triphosphate)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

How many RNA polymerases are in bacteria? Eukaryotes?

A

1 in bacteria, 3 in eukaryotes (RNA pol. I, II, III)

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

The structure of rNTP

A

a base, ribose sugar and 3 phosphates

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

What is the strand that is read by RNA polymerase called?

A

template strand

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

The sequence of mRNA matches with what strand?

A

coding (non-template) strand

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

What protein does RNA polymerase need in order initiate transcription?

A

a sigma protein

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

What does a sigma protein do?

A
  • creates a holoenzyme by binding to RNA polymerase
  • guide RNA pol. to specific locations (promoters) where transcription should begin
  • a regulatory protein
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What binds to DNA first?

A

sigma protein (not RNA pol.)

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

Where on the DNA does sigma bind to?

A

promoter region

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

What are promoters?

A

initiates transcription (NOT actual start)

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

What the 2 promoter regions of bacterial DNA?

A
  • 35 box (TTGACA)

- 10 box (TATAAT)–10 bases from where RNA pol. starts transcription

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

What place does bacterial transcription actually begin?

A

the +1 region

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

Are sigma proteins present in eukaryotes?

A

No.

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

In eukaryotes, what acts analogous to a sigma in bacteria?

A

basal transcription factors (need many to begin transcription)

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

What does RNA pol. I do?

A

synthesis of large ribosomal units

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

What does RNA pol. II do?

A

synthesis or mRNA

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

What does RNA pol. III do?

A

synthesis of small ribosomal units and tRNA

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

In eukaryotes, what is the promoter?

A

TATA box located 30 bases upstream to transcription site

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

What happens once sigma is released from promoter?

A

initiation ends, synthesis (elongation) begins

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

Once DNA helix unwinds to form what (in transcription of Protein synthesis)?

A

Transcription bubble

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

What is elongation?

A

when RNA pol. begins synthesizing mRNA

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

What do zipper amino acids do?

A

help separate the mRNA from the template DNA strand

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

What do rudder amino acids do?

A

help maneuver the template and non-template strand through the channels of RNA pol.

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

How does transcription ends?

A

when RNA pol. reaches a termination signal, RNA loops on itself to form a hairpin, therefore disrupting the interaction between RNA pol. and the mRNA

26
Q

What is the difference between a nucleotide and a nucleoside?

A

nucleosides are similar to nucleotides except that they don’t have a phosphate group

27
Q

How many phosphates can a nucleotide have?

A

up to 3

28
Q

What are ribonucleosides?

A

RNA base + ribose sugar

29
Q

What are deoxyribonucleosides?

A

DNA base + deoxyribose sugar

30
Q

What is nucleic acid?

A

a polymer of nucleotide monomers linked together

31
Q

Why does transcription and translation happen simultaneously in bacteria?

A

because bacterial (prokaryotic) cells lack a nucleus

32
Q

What is an exon?

A

coding region of pre mRNA that is kept after splicing

33
Q

What is an intron?

A

non-coding region of pre mRNA that is removed by spliceosomes

34
Q

In eukaryotes, what types of RNA processing are needed before mRNA can be translated?

A

1) Capping with 5’ cap
2) Poly A tail at the 3’ end of RNA strand
3) Splicing out the introns

35
Q

What is the purpose of capping the 5’ end of mRNA?

A
  • to protect the 5’ end from degradation by exonucleases
  • to stabilize mRNA before translation
  • recognition site for translation?
36
Q

What is the purpose of adding a row of adenine to the 3’ end of mRNA (poly A tail)?

A

-to protect the end from degradation

37
Q

snRNPs are known as:

A

small nuclear ribonucleoproteins

38
Q

In vitro hybridization of mRNA and their DNA templates produce loops of mRNA-DNA hybrids. These loops are

A

single-stranded DNA and they represent introns

39
Q

What happens to the mature mRNA after post-transcriptional processing (in eukaryotes)?

A

exported for translation

40
Q

What is the advantage of alternative splicing?

A
  • a variety of mRNA transcripts can be produced

- this leads to the synthesis of many different proteins

41
Q

What is translation?

A

peptides and proteins are sythesized from mRNA

42
Q

What is a peptide?

A

a short chain of amino acids linked together by a peptide bond (ie. dipeptides, tri-peptides, polypeptides, etc.)

43
Q

What molecules are required for translation?

A
  • mRNA
  • tRNA
  • ribosome
  • amino acids
44
Q

What is an aminoacyl tRNA?

A

tRNA + amino acid

45
Q

What are the main components of tRNA?

A

-anticodon, attached amino acid to CCA region and nucleotides (loops and secondary structured stem)

46
Q

What are ribosomes made up of?

A

large and small subunits

47
Q

What does the large subunit of ribosomes do?

A

-where peptides are formed

48
Q

What does the small subunit of ribosomes do?

A

holds the mRNA in place during translation

49
Q

What are anticodons?

A

set of 3 ribonucletides that form base pairs with the mRNA codon

50
Q

What the 3 sites of ribosomes involved in translation?

A
  • A (acceptor or aminoacyl) site
  • P (peptide formation)site
  • E (exit) site
51
Q

The A site is responsible for:

A

bringing in the tRNA with AA attached

52
Q

What happens in the P site?

A

tRNA holds the growing polypeptide chain

53
Q

What happens in the E site?

A

the tRNA has no AA attached

54
Q

What is the ribosomal binding site?

A

the mRNA sequence that forms complimentary base pairs with the rRNA from the small subunit
-the start of initiation of translation

55
Q

When is initiation complete?

A

when the large sununit joins the ribosomal complex

56
Q

The process of initiation (translation)

A

1) mRNA binds to small subunit via complimentary base pairing
2) Aminoacyl tRNA carrying f-met binds to AUG codon of mRNA
3) Large subunit binds, completing complex and leaving the initiator aminoacyl tRNA in the P site

57
Q

The process of elongation (translation)

A

1) arrival of aminoacyl tRNA to A site
2) peptide bond forms (peptide chain is transferred from tRNA in P site to tRNA in A site)
3) translocation-repeat down the length of mRNA (ribosome moves down length of mRNA in 5’ to 3’ direction)

58
Q

Do tRNAs have a stop anticodon?

A

No.

59
Q

How does protein synthesis end?

A

when release factor fills the empty A site

60
Q

What do release factors do?

A
  • fills A site because similar in shape, size as tRNA
  • hydrolyzes the bond linking tRNA in P site to polypeptide chain
  • releases polypeptide chain
61
Q

What sequences in the tRNA should be conserved? variable?

A

Conserved: the nucleotide part
Variable: the anticodon and amino acid part

Biology 1A03 (4 decks)

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