Brainscape's Knowledge GenomeTM

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


See full index

Biology > 3.4.2 - DNA and protein synthesis > Flashcards

3.4.2 - DNA and protein synthesis Flashcards

1
Q

what is a genome

A

the complete set of genes in a cell is known as the cell’s genome

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

what is a proteome

A

the full range of proteins that the cell is able to produce is known as a proteome

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

what is protein synthesis

A

protein synthesis is the production of proteins (polypeptides) from the information contained within a cell’s DNA

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

what is protein synthesis also known as

A

polypeptide synthesis

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

what is the 1st stage of protein synthesis?

A

transcription

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

what is transcription briefly

A

where the DNA code is copied into a molecule called mRNA

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

what is the 2nd stage of protein synthesis

A

translation

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

what is translation briefly

A

where the mRNA joins with a ribosome and the code it carries is used to synthesise a protein

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

what is RNA

A

single polynucleotide strand containing uracil instead of thymine. uracil always pairs with adenine during protein synthesis

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

name 2 different types of RNA

A

mRNA - messenger RNA
tRNA - transfer RNA

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

where is mRNA made?

A

mRNA is made during transcription

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

what does mRNA do?

A

mRNA carries the genetic code from the DNA to the ribosomes, where it’s used to make a protein during translation

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

what is mRNA?

A

mRNA is a single polynucleotide strand

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

what are 3 adjacent bases called in mRNA?

A

in mRNA, groups of 3 adjacent bases are usually called codons (sometimes called triplets/base triplets)

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

what is tRNA involved in?

A

tRNA is involved in translation

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

what does tRNA do?

A

tRNA carries the amino acids that are used to make proteins to the ribosomes

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

what is tRNA?

A

tRNA is a single polynucleotide strand that’s folded into a clover shape

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

what holds tRNA in its shape

A

hydrogen bonds between specific base pairs hold the molecule in this shape

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

tRNA : anticodons

A

each tRNA molecule has a specific sequence of 3 bases at one end called an anticodon and has an amino acid binding site at the other end

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

where does transcription happen in eukaryotic cells?

A

in eukaryotic cells, transcription happens in the nucleus

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

where does transcription happen in prokaryotic cells?

A

in prokaryotic cells, transcription takes place in the cytoplasm

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

what happens first in transcription

A

RNA polymerase attaches to the DNA

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

transcription: RNA polymerase attaches to the DNA
step one

A

transcription starts when RNA polymerase (an enzyme) attaches to the DNA double helix at the beginning of a gene

24
Q

transcription: RNA polymerase attaches to the DNA
step two

A

in eukaryotes, the hydrogen bonds between the 2 DNA strands in the gene are broken by a DNA helicase attached to the RNA polymerase. This separates the strands, and the DNA molecule uncoils at that point, exposing some of the bases. one of the strands is then used as a template to make an mRNA copy

25
Q

what happens second in transcription

A

complementary mRNA is formed

26
Q

transcription: complementary mRNA is formed
step one

A

the RNA polymerase lines up free RNA nucleotides alongside the exposed bases on the template strand. the free bases are attracted to the exposed bases

27
Q

transcription: complementary mRNA is formed
step two

A

specific complementary base pairing means that the mRNA strand ends up being a complementary copy of the DNA template strand (except the base T is replaced by U in RNA)

28
Q

transcription: complementary mRNA is formed
step three

A

once the RNA nucleotides have paired up with their specific bases on the DNA strand, they’re joined together by RNA polymerase, forming an mRNA strand

29
Q

what happens 3rd in transcription

A

RNA polymerase moves down the DNA strand

30
Q

transcription: RNA polymerase moves down the DNA strand
step one

A

the RNA polymerase moves along the DNA, assembling the mRNA strand.

31
Q

transcription: RNA polymerase moves down the DNA strand
step two

A

the hydrogen bonds between the uncoiled strands of DNA reform once the RNA polymerase has passed by and the strands coil back into a double helix

32
Q

what happens 4th in transcription?

A

RNA polymerase reaches stop signal

33
Q

transcription: RNA polymerase reaches stop signal
step one

A

when RNA polymerase reaches a particular sequence of DNA called a stop signal, it stops making mRNA and detaches from the DNA

34
Q

transcription: RNA polymerase reaches stop signal
step two

A

in eukaryotes, mRNA moves out of the nucleus through a nuclear pore and attaches to a ribosomes in the cytoplasm where the next stage of protein synthesis takes place

35
Q

editing mRNA
does transcription produce the same products in eukaryotes and prokaryotes?

A

transcription produces different products in eukaryotes and prokaryotes

36
Q

editing mRNA
in eukaryotes what are copied into mRNA during transcription

A

in eukaryotes, the introns and exons are both copied into mRNA during transcription

36
Q

editing mRNA
splicing

A

mRNA strands containing introns and exons are called pre-mRNA. Splicing then occurs = introns are removed and the exons joined together

37
Q

editing mRNA
where does splicing take place

A

splicing takes place in the nucleus

38
Q

editing mRNA
what happens after splicing

A

the mRNA leaves the nucleus for the next stage of protein synthesis (translation)

39
Q

editing mRNA
how is mRNA produced in prokaryotes

A

in prokaryotes, mRNA is produced directly from the DNA without splicing taking place

40
Q

editing mRNA
why doesn’t splicing occur in prokaryotes

A

there is no need for splicing as there is no introns in prokaryotic DNA

41
Q

where does translation occur

A

in eukaryotes and prokaryotes, translation takes place at the ribosomes in the cytoplasm

42
Q

what happens during translation

A

amino acids are joined together to make a polypeptide chain (proteins), following the sequence of codons carried by the mRNA

43
Q

translation
step one

A

mRNA attaches itself to a ribosome and tRNA molecules carry amino acids to it. ATP gives the energy needed for the bond between the amino acid and the tRNA molecule to form

44
Q

translation
step two

A

a tRNA molecule (carrying an amino acid), with an anticodon that’s complementary to the 1st codon on the mRNA, attaches itself to the mRNA by complementary base pairing. a 2nd tRNA molecule attaches itself to the next codon on the mRNA in the same way

45
Q

translation
step three

A

the 2 amino acids attached to the tRNA molecules are joined by a peptide bond. the first tRNA molecule moves away, leaving its amino acid behind

46
Q

translation
step four

A

a 3rd tRNA molecule binds to the next codon on the mRNA. its amino acid binds to the 1st 2 and the 2nd tRNA molecule moves away. this process continues, producing a chain of linked amino acids (polypeptide chain), until there’s a stop signal on the mRNA molecule

47
Q

translation
step five

A

the polypeptide chain (protein) then moves away from the ribosome and translation is complete

48
Q

what is the genetic code

A

the genetic code is the sequence of base triplets (codons) in mRNA which code for specific amino acids

49
Q

why is genetic code non-overlapping?

A

base triplets don’t share their bases

50
Q

why is the genetic code degenerate?

A

there are more possible combinations of triplets than there are amino acids (20 amino acids, 64 possible triplets)

51
Q

what does the genetic code being degenerate do?

A

some amino acids are coded for by more than 1 base triplet

52
Q

do all triplets code for amino acids

A

not all triplets code for amino acids

53
Q

what are stop signals

A

some triplets are used to tell the cell when to stop production of a protein, found at the end of mRNA

54
Q

what are start signals

A

tell the cell when to start protein production, found at the start of mRNA

55
Q

what does it mean by the genetic code being universal

A

the same specific base triplets code for the same amino acid in all organisms

Biology (12 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions