Brainscape's Knowledge GenomeTM

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


See full index

BIOLOGY 1210 > Transcription, RNA, and Genetic Code > Flashcards

Transcription, RNA, and Genetic Code Flashcards

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

what are the 2 main stages involved in going from a gene to protein? what is their primary function?

A
  1. transcription - synthesis of RNA from a DNA template

2. translation - synthesis of polypeptide

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

when do transcription and translation occur in prokaryotes? Eukaryotes?

A

prokaryotes –> simultaneously
Eukaryotes –> transcription occurs while in nucleus, and
translation while in cytoplasm

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

what is RNA? what does it consist of? what are it’s main roles?

A

ribonucleic acid

  • consists of a single strand of nucleotides
  • main roles are coding, decoding, regulation and expression of genes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

when are all RNAs produced? how are they produced?

A
  • produced during transcription

- produced by copying one DNA strand of a gene (template strand)

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

what is the template strand? which strand is the template?

A
  • the single DNA strand of the gene that is being copied.

- Which strand is the template varies with gene

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

Transcription builds from … end to … end; meaning that the template strand is copied from … end to … end.

A

Transcription –> from 5’ to 3’

Template –> copied 3’ to 5’

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

what is made from the template strand? how is this done?

A
  • a complementary RNA molecule

- done by pairing complementary nitrogenous bases

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

if the following nitrogenous bases are present on the template DNA strand, what is the pairing nitrogenous base that will be produced in the RNA strand? (name the base and the pairing base)

  1. T
  2. A
  3. C
  4. G
A
  1. Thymine (not found in RNA) –> Adenine
  2. Adenine –> Uracil (not found in DNA)
  3. Cytosine –> Guanine
  4. Guanine –> Cytosine
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what enzyme is responsible for carrying out transcription? what does it use as substrates?

A

RNA Polymerase

-uses nucleotide triphosphates: ATP, UTP, CTP, GTP

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

what are nucleotide triphosphates? what do those consist of?

A
  • they are nucleotide monomers that have 2 additional phosphate groups (ATP, UTP, CTP, GTP)
  • these consist of a nitrogenous base (adenine, uracil, cytosine, guanine), a ribose (5-carbon sugar), and 3 phosphates
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what do the 2 extra phosphate groups in nucleotide triphosphates do?

A
  • they’re used as energy sources to drive the energy requiring process of transcription
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what are the three stages of transcription?

A
  1. Initiation
  2. Elongation
  3. Termination
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

during initition stage, what is the promoter?

A

it is the sequence (or region) of DNA at the beginning of the gene (where transcription of a gene is started)

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

what are the steps involved in initiation stage?

A
  1. RNA polymerase binds to promoter and separates DNA strands
  2. RNA polymerase Initiates transcription at start point (Initiation site)
  3. RNA polymerase synthesizes complementary RNA strand by adding complementary nucleotides on template strand
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what happens during elongation stage? what happens to DNA strands?

A

-RNA polymerase adds RNA nucleotides at 3’ end of
the transcript –> causing the RNA transcript to elongate

-DNA strands reform double helix after RNA polymerase passes

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

what happens during termination stage?

A
  1. RNA polymerase stops transcribing RNA from DNA when it reaches terminator sequence on DNA
  2. RNA transcript is released
  3. RNA polymerase releases from DNA
  4. Double stranded DNA reforms
17
Q

what is the terminator sequence?

A

it is the sequence (or region) of DNA at the end of the gene being copied (where transcription of a gene is finished)

18
Q

what are the 3 types of RNA molecules required for translation (made during transcription)?

A
  1. Ribosomal RNA = rRNA
  2. Transfer RNA = tRNA
  3. Messenger RNA = mRNA
19
Q

real quick, what is an amino acid? how many amino acids are there? what is a polypeptide?

A

amino acid –> protein monomer
-20 different amino acids
polypeptide –> protein polymer ie. chain of monomers

20
Q

what is tRNA? what is it’s role? what does it do?

A

Transfer RNA = tRNA

  • its role is to bring amino acids to the ribosome for assembly into polypeptides
  • acts as an intermediate between mRNA and amino acids
  • it translates a particular mRNA codon into a particular amino acid
21
Q

tRNA structure:

  1. single stranded or double stranded?
  2. what shape does it take?
  3. how many nucleotides long is a tRNA strand?
  4. how does it physically act as an intermediate between amino acids and mRNA?
A
  1. single stranded (all RNA molecules are single stranded, silly)
  2. 2D shape drawn as cloverleaf structure to show “double stranded” regions (where it folds back on itself); actually 3D shape is folded L-shape
  3. ~80 nucleotides long
  4. carries an amino acid at one end and “attaches” to mRNA on the other
22
Q

how does tRNA attach to mRNA?

A

-tRNA has an anticodon on one end

23
Q

what is mRNA codon? what is tRNA anticodon? what is the function/purpose of these?

A

mRNA codon –> unit made up of a 3-base segment of an mRNA that will code for a specific amino acid in a ribosome

tRNA anticodon –> unit made up of 3 nucleotides that pair with complementary codon on mRNA

-function is to temporarily bind together so that the tRNA can translate that particular mRNA codon into a particular amino acid

24
Q

what are the functions of a ribosome?

A

-to facilitate specific coupling of tRNA anticodons
with mRNA codons during protein synthesis
- by holding tRNA and mRNA in correct position it allows for the addition of a new amino acid to the end of the polypeptide chain
-catalyzes peptide bond formation

25
Q

what are the subunits of a ribosome? what are these subunits made up of? when do the subunits join together to become a functional ribosome?

A
  • one large and one small subunit
  • subunits made of protein + rRNA
  • large and small subunits join to form a functional ribosome only when attached to a mRNA molecule
26
Q

how many binding sites are there for mRNA/where are they?

A

-only 1 binding site for mRNA, found on small ribosomal subunit

27
Q

how many tRNA binding sites does a ribosome have? what are they called/what are their functions? where are these binding sites located?

A

-3 tRNA binding sites
A site –> where incoming tRNA binds
P site –> where tRNA attached to growing peptide chain is bound
E site –> where tRNA that no longer carries an
amino acid binds briefly before exiting ribosome

-binding sites bridge small and large subunits

28
Q

what is mRNA? what is it translated into/where?

A

messenger RNA
-its a complementary strand to the nucleotide sequence of a specific gene

-Nucleotide sequence is translated into a polypeptide
at the ribosome

29
Q

what does genetic code give us? do all species use the same genetic code?

A

gives sequence of nucleotides which can be translated
into sequence of amino acids
- yes

30
Q

how many nucleotides in mRNA does it take to specify 1 amino acid? how many different nucleotides are there in a mRNA strand? how many different ways can nucleotides be combined into sets of 3, what are these called?

A
  • 3
  • 4
  • can be combined 64 ways to make 64 different codons
31
Q

how many different codons signal start to translation? how many different codons signal stop?

A
  • 1 codon signals a START (when located in correct position at 5’ end mRNA)
  • 3 codons signal a STOP
32
Q

what is meant by the “Genetic code is redundant”?

A

means that most amino acids can be specified (signaled to be translated) by more than one codon

33
Q

what is the specific codon for START? what amino acid does it code for?

A

AUG (adenine, uracil, guanine)

-codes for amino acid Met

34
Q

how is mRNA read? in which direction is it read? hwta needs to be correct in order for the mRNA to be read? what ensures this?

A

-read as series of non-overlapping codons
-read in 5’ to 3’ direction
-the “reading frame” must be correct, meaning the correct sequencing of 3 basses is read togethe
-Start codon ensures translation begins in the
correct reading frame

BIOLOGY 1210 (26 decks)

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