D1.2 Protein Synthesis

Question 1

The _____ will have the same sequence as the ____ strand of the ____ but all Ts will be replaced with Us.

Answer 1

mRNA, coding, DNA

Question 2

RNA polymerase connects _____ RNA bases to the DNA during _________.

Answer 2

complementary, transcription

Question 3

tRNA brings a amino acid (_____) and reads nucleotides in “series of three” known as a ____.

Answer 3

anticodon, codon

Question 4

The anticodon for AUG is ____ . It codes for ____.

Answer 4

UAC, methionine

Question 5

the tRNA leaves but the amino acid forms a _____ bond with the 2nd amino acid.

Answer 5

peptide bond

Question 6

List complementary base pairs:

Answer 6

A-T and C-G
(The base U pairs with A in RNA.)

Question 7

___ bonds are found between the bases of the DNA strands.

Answer 7

Hydrogen

Question 8

What would be the mRNA stand if the DNA strand was : TAGCGA

Answer 8

AUC-GCU (The mRNA will have the same sequence as the coding strand of the DNA but all Ts will be replaced with Us.

Question 9

The mRNA will have the same sequence as the coding strand of the DNA but all ___ will be replaced with ___.

Answer 9

Thymine, uracil

Question 10

In eukaryotes, Transcription is an essential step in ______ _______.

Answer 10

gene expression

Question 11

Transcription:

Answer 11

synthesising(making) RNA using DNA as a template

Question 12

What’s the function of ribosomes during translation.

Answer 12

catalyse the formation of peptide bonds

Question 13

tRNA __________ during translation.

Answer 13

attaches to and delivers amino acids to the ribosomes

Question 14

The mRNA binds to ________ of the ribosome during translation.

Answer 14

the small subunit

Question 15

Identify which option refers to ‘degeneracy’ in the genetic code.

Answer 15

The existence of multiple codons that can code for the same amino acid.

Question 16

Universality of the the genetic code: is the ____ for all organisms. The codons code for the ___ amino acids regardless of the type of organism.

Answer 16

same

Question 17

To find the amino acid that the tRNA anticodon brings, you can use a _______.

Answer 17

codon chart (reads mRNA sequence)

Question 18

Elongation in translation involves the formation of _____ bonds between ____.

Answer 18

peptide, amino acid

Question 19

Point mutations.

Answer 19

insertions, deletions, and substitutions of a single nucleotide

Question 20

Which mutation occurs in sickle cell anaemia.

Answer 20

substitution mutation

Question 21

In transcription, the RNA polymerase must bind to the _____ region before it can begin transcribing the gene beginning at the start codon.

Answer 21

promoter

Question 22

directionality of transcription refer to

Answer 22

The direction of RNA polymerase movement along the DNA template strand.

Question 23

Due to how it bonds to the ribosome, the mRNA is always read in the _____ direction in ______.

Answer 23

5′ to 3′, translation

Question 24

Describe the role of non-coding sequences in DNA.

Answer 24

They regulate gene expression and provide functional diversity.

Question 25

The alternative splicing process allows for production of multiple _____ from a single gene.

Answer 25

proteins

Question 26

Which refers to post-transcriptional modification of mRNA in eukaryotes.

Answer 26

The processing and modification of pre-mRNA into mature mRNA.

Question 27

Name the post-transcriptional modification of mRNA in eukaryotes.

Answer 27

I. addition of a 5′ cap II. addition of a poly-A tail III. remove introns

Question 28

Identify how alternative splicing produces variants of a protein.

Answer 28

By modifying the sequence of exons included in the mature mRNA. (variety of polypeptides from the same gene.)

Question 29

What's true about variants of a protein generated through alternative splicing.

Answer 29

They have different functions or properties.

Question 30

initiation (translation)

Answer 30

The ribosome binds to mRNA molecule.

Question 31

What's involved in modification of polypeptides to their functional state.

Answer 31

The folding, cleavage and/or chemical modification of the polypeptide.

Question 32

Role of proteasomes.

Answer 32

Breaking down and recycling unwanted or damaged proteins. (provides a source of amino acids to the cell)

Question 33

Role of pre-proinsulin in insulin production.

Answer 33

Pre-proinsulin is an inactive precursor that undergoes post-translational modification to become insulin. (Pre-proinsulin is the translational product of the insulin gene. It is then modified post-translation to become insulin.)

Question 34

The significance of proper protein folding for biological function demonstrates ___________.

Answer 34

the modification of polypeptides to their functional state using pre-proinsulin.

Question 35

transcription-Sense Strand

Answer 35

The DNA sense strand has the same sequence as the mRNA, except that thymine (T) in DNA is replaced by uracil (U) in RNA. (The sense strand is the DNA strand that IS NOT read by the mRNA)

Question 36

Translation-Antisense Strand

Answer 36

the strand that is actually used for transcription (mRNA does base pairing with)

Question 37

DNA is most stable when _____. When strand is temporarily separated ________ can occur.

Answer 37

strands are together, mutations

Question 38

All cells in the body contain the full _____, however not all genes are ______.

Answer 38

genome (genetic code), expressed

Question 39

There is a _____ codon and _____ codon on each mRNA strand

Answer 39

start, stop

Question 40

tRNA stands for ______.

Answer 40

transfer RNA

Question 41

Ribosome has ___ subunits. The small subunit _____. The large subunit _________.

Answer 41

2, binds to mRNA, has tRNA binding sites & catalytic sites to create peptide bonds

Question 42

Possible combinations of the bases

Answer 42

64 amino acid combinations

Question 43

A,P,E site on the large subunit of the ribosome during translation

Answer 43

A - initial binding site for tRNA, peptide bond formed P - "Empty" tRNA moves here as a new tRNA binds to the mRNA in the A site. E - Exit site

Question 44

The movement through the A, P, and E sites result in ______.

Answer 44

elongation of the polypeptide chain

Question 45

Mutations are ____. Base substitutions can ________.

Answer 45

changes in bases sequence(s) of a gene - change one amino acid or overage protein structure

Question 46

______ mutations results in sickle cell anemia

Answer 46

hemoglobin

Question 47

Both transcription and translation happen in the __________ end.

Answer 47

5' to 3'

Question 48

Section of DNA that serves as a binding site for RNA polymerase or other proteins that control transcription: beginning of a gene.

Answer 48

Promoter

Question 49

Molecules that regulate gene expression by promoting or inhibiting transcription

Answer 49

Transcription factors

Question 50

non-coding region.

Answer 50

not coded for polypeptides ( they are not a gene)

Question 51

list examples of non-coding regions:

Answer 51

-base sequences that produce tRNA or rRNA -Promoters -Telomeres (structural DNA at the end of chromosomes) -Introns (edited out after transcription)

Question 52

Post transcriptional modification happens only is _____ cells. This is because they have a _____ which is separated from cytoplasm. It allows to _________.

Answer 52

eukaryotic, nucleus, make different versions of a protein with same gene

Question 53

Mature mRNA is _____________.

Answer 53

the final design of mRNA before it leaves the nucleus. (removal of introns, addition of 5'cap, poly- A tail)

Question 54

Alternative splicing

Answer 54

removing different introns to produce different versions of a protein from a single gene

Question 55

tRNA activating enzyme

Answer 55

attaches correct amino acid to the tRNA (requires ATP)(different enzyme for a new amino acid)

Question 56

Polypeptides become proteins when its ___________ into its _____.

Answer 56

modified/folded, functional shape

Question 57

Proteasomes:

Answer 57

enzyme complex that breaks down proteins into short polypeptides, which can be broken down into amino acids later on (requires enzyme, ATP)

Question 58

Insulin is a polypeptide hormone

Answer 58

- preproinsulin -modified: -insulin codes for 110 amino acids -rough ER removes 24 amino acids (Proinsulin) -proinsulin is folded into tertiary structure with disulfide bonds - Some insulin removed from middles, leaves behind 2 linked chains with 51 amino acids (insulin)

Question 59

Amino acids are joined together at the ___ site by a peptide bond.

Answer 59

P

Question 60

Transcription (initiation)

Answer 60

RNA polymerase binds to a specific DNA sequence called a promoter.

Question 61

Transcription (Elongation)

Answer 61

RNA polymerase synthesizes an RNA molecule (mRNA) by adding nucleotides to the growing chain, moving along the DNA template.

Question 62

Transcription (Termination)

Answer 62

RNA polymerase reaches a termination signal, causing the RNA molecule and RNA polymerase to detach from the DNA.

Question 63

Translation (Initiation)

Answer 63

The small ribosomal subunit binds to the mRNA molecule, and a tRNA molecule carrying an amino acid binds to the start codon on the mRNA.

Question 64

Translation (Elongation)

Answer 64

The ribosome moves along the mRNA, adding amino acids to the growing polypeptide chain, guided by the codons on the mRNA.

Question 65

Translation (Termination)

Answer 65

Translation stops when the ribosome reaches a stop codon on the mRNA, causing the release of the completed polypeptide chain.