TEST 2: Gene Expression and Regulation

Question 1

How does DNA store genetic information?

Answer 1

DNA molecule store, genetic information in the sequence of nucleotides

Question 2

Define gene

Answer 2

A segment of DNA that contains the instructions to build a single protein

Question 3

Define transcription

Answer 3

The process by which the information contained within a single gene is copied from the DNA to a pre-mRNA strand

Question 4

Define mRNA processing

Answer 4

MRNA processing converts, the pre-mRNA strand into an mRNA strand

Question 5

Define translation

Answer 5

The process by which the information of an mRNA strand is used to build a protein

Question 6

Describe the steps a cell uses to make a protein

Answer 6

DNA, which is built using for DNA nucleotides TAG andC go through transcription which breaks it down into an mRNA strand, which is built using four nucleotides UAG and C.

mRNA processing converts pre-MRNA to mRNA

Then the RNA is translated into a protein, which is built using 20 amino acids

Question 7

What is the overall purpose of combine processes of transcription, mRNA processing and translation?

Answer 7

To produce a functional protein from gene

Question 8

What is the purpose of transcription?

Answer 8

To create mRNA copy of a gene DNA sequence to allow genetic information stored in DNA to be used for protein synthesis without damaging the original DNA

Question 9

Three major steps of transcription

Answer 9

Initiation, elongation, termination

Question 10

Describe initiation in transcription

Answer 10

• RNA polymerase binds to the promoter region of the gene
• DNA unwinds, exposing the template strength for RNA synthesis

Question 11

Describe elongation in transcription

Answer 11

• RNA polymerase moves along the DNA template strand
• Complementary RNA nucleotides are added to form a pre-MRNA strand (U instead of T)
• DNA behind the RNA polymerase rewinds back into a double helix

Question 12

Describe termination in transcription

Answer 12

• RNA polymerase reaches a termination sequence in DNA
  -MRNA transcript detach from DNA

Question 13

Define promoter

Answer 13

Specific DNA sequence that serves as binding site for RNA polymerase, marking the beginning of a gene, where transcription starts

Question 14

Where is the promoter located?

Answer 14

Before the start site (TATA box)

Question 15

Define termination sequence

Answer 15

Specific sequence of DNA that signals the end of transcription

Question 16

Where is a termination sequence located?

Answer 16

At the end of a gene

Question 17

How does the temp of DNA strand differ from the complementary DNA strand

Answer 17

The complementary strand is the opposite of the template, directionality, base pairing (U)

Question 18

Purpose of mRNA processing

Answer 18

To prepare the mRNA for export from the nucleus to the cytoplasm, and to ensure that it is properly stabilized for translation into a protein

Question 19

What occurs during mRNA processing?

Answer 19

5‘ capping
Splicing
Poly a tail add

Question 20

Define 5’ capping

Answer 20

A modified guanine nucleotides is added to the 5’ end of the pre-mRNA to protect the mRNA and help the ribosome recognize the mRNA for translation

Question 21

Define splicing

Answer 21

Introns are removed from the pre-mRNA and the exons are joined together to form the mature mRNA

Question 22

Define poly a tail

Answer 22

A string of adenine nucleotides is added to the 3’ end of the mRNA, which helps stabilize the mRNA and aids a nuclear export and promotes translation initiation

Question 23

How does pre-mRNA differ from mRNA

Answer 23

Pre-mRNA has both introns and Exons, no cap and tail, and is not functional for translation

mRNA is a functional transcript, ready to leave the nucleus and translate into protein

Question 24

Define exon

Answer 24

Expressed in the mRNA, present in pre-mRNA and mRNA, contains info to build protein

Question 25

Define Cap and tail and its purpose

Answer 25

Additional nucleotides added to both ends of mRNA Allows the mRNA to move through nuclear poor and to buy two ribosome

Question 26

True or false

Answer 26

MRNA splicing in the addition of the cap and tail are independent processes that are occurring at the same time

Question 27

Define introN

Answer 27

Intervening non-coding sequence that is present in the pre-RNA but not to mRNA, and does not contain information to build the protein, but often contains sequences that regularly whether transcription occurs

Question 28

Purpose of translation

Answer 28

To synthesize a protein based on the information encoded in mRNA

Question 29

Molecules and structures required for translation

Answer 29

mRNA, ribosome, tRNa

Question 30

What does mRNA specify?

Answer 30

The amino acid sequence of a protein

Question 31

What does TRNA do?

Answer 31

Brings a specific amino acid to the ribosome as a protein is being made

Question 32

Three major steps of translation

Answer 32

Initiation allegation and termination

Question 33

Define translation initiation

Answer 33

Robo assembles on mRNA at the start codon

Question 34

Define translation elongation

Answer 34

Ribosome moves along mRNA one codon at a time each step a TRNA with the appropriate anticodon binds to the corresponding codon on the mRNA Amino acid carried by TRNA is blinded

Question 35

Define translation termination

Answer 35

Stop codon as encountered releases, polypeptide, and dissembles

Question 36

Define codon

Answer 36

Sequence of three nucleotides that encodes a specific amino acid or signals the end of protein synthesis

Question 37

Codon location

Answer 37

Found an mRNA sequence arranged, sequential along the mRNA molecule

Question 38

Define anticodon

Answer 38

Sequences of three nucleotides that is complementary to a codon on the mRNA and ensures that the correct amino acid is brought to ribosome during translation

Question 39

Location of anticodon

Answer 39

Located on the TRNA molecule, which is carrying a specific amino acid to the ribosome

Question 40

What evidence do we have that the same genetic code is used by all organisms

Answer 40

The same set of codons in mRNA codes for the same amino acids in all organisms