4_Transcription_Translation_Flashcards

Question 1

What is the central dogma of molecular biology?

Answer 1

DNA → RNA → Protein.

Question 2

What are the two main processes involved in the central dogma?

Answer 2

Transcription (DNA to RNA) and Translation (RNA to Protein).

Question 3

Why are proteins essential for life?

Answer 3

They fight disease, build tissues, act as enzymes, and serve as signals.

Question 4

What determines a protein’s structure and function?

Answer 4

The unique sequence of its 20 possible amino acids.

Question 5

What is transcription?

Answer 5

The process of synthesizing mRNA from a DNA template.

Question 6

Where does transcription occur in eukaryotes?

Answer 6

In the nucleus.

Question 7

What percentage of the human genome is transcribed into mRNA?

Answer 7

Less than 2%.

Question 8

What carries the genetic code from the nucleus to the cytoplasm?

Answer 8

Messenger RNA (mRNA).

Question 9

What is the role of RNA polymerase?

Answer 9

To transcribe DNA into mRNA.

Question 10

What are transcription factors?

Answer 10

Proteins that regulate the initiation of transcription.

Question 11

What is the function of a promoter region?

Answer 11

It binds RNA polymerase to initiate transcription.

Question 12

What are introns and exons?

Answer 12

Introns are non-coding regions, and exons are coding sequences.

Question 13

What happens during initiation?

Answer 13

RNA polymerase binds to the promoter, and DNA unwinds.

Question 14

What happens during elongation?

Answer 14

RNA polymerase synthesizes mRNA in the 5’ to 3’ direction.

Question 15

What signals the end of transcription?

Answer 15

A termination signal in the DNA.

Question 16

What is added to the 5’ end of mRNA?

Answer 16

A 7-methylguanosine cap.

Question 17

What is added to the 3’ end of mRNA?

Answer 17

A poly(A) tail.

Question 18

What is splicing?

Answer 18

The removal of introns and joining of exons in pre-mRNA.

Question 19

What is alternative splicing?

Answer 19

Producing multiple protein variants from one gene.

Question 20

What is translation?

Answer 20

The process of converting mRNA into a protein.

Question 21

Where does translation occur?

Answer 21

In the ribosome.

Question 22

What are the three main steps of translation?

Answer 22

Initiation, elongation, and termination.

Question 23

What is the role of tRNA in translation?

Answer 23

It carries amino acids to the ribosome.

Question 24

What is a codon?

Answer 24

A three-nucleotide sequence that codes for an amino acid.

Question 25

How many codons specify amino acids?

Answer 25

61 codons.

Question 26

What are the stop codons?

Answer 26

UAA, UAG, UGA.

Question 27

Is the genetic code universal?

Answer 27

Yes, nearly all organisms use the same code.

Question 28

What happens during initiation?

Answer 28

The small ribosomal subunit binds to mRNA, and the first tRNA pairs with the start codon.

Question 29

What happens during elongation?

Answer 29

Amino acids are added one by one, forming a polypeptide chain.

Question 30

What happens during termination?

Answer 30

A stop codon signals the release of the polypeptide.

Question 31

What modifications occur after translation?

Answer 31

Folding, chemical group additions, and cleavage into smaller peptides.

Question 32

Why are post-translational modifications important?

Answer 32

They ensure the protein's proper function and activity.

Question 33

Where does transcription occur in prokaryotes?

Answer 33

In the cytoplasm.

Question 34

Where does transcription occur in eukaryotes?

Answer 34

In the nucleus.

Question 35

Do prokaryotes modify their mRNA after transcription?

Answer 35

No, the primary transcript is the mature mRNA.

Question 36

What type of mRNA do prokaryotes produce?

Answer 36

Polycistronic mRNA (one mRNA can encode multiple proteins).

Question 37

What is an ORF?

Answer 37

A sequence of DNA with a start codon, stop codon, and potential to code for a protein.

Question 38

Why are ORFs important?

Answer 38

They help identify coding regions in DNA.

Question 39

What is the central enzyme in transcription?

Answer 39

RNA polymerase.

Question 40

What molecule brings amino acids to the ribosome?

Answer 40

Transfer RNA (tRNA).

Question 41

What is the first amino acid in protein synthesis?

Answer 41

Methionine (coded by AUG).

Question 42

How is mRNA stabilized in eukaryotes?

Answer 42

By a 5' cap and poly(A) tail.

Question 43

What are ribosomes made of?

Answer 43

rRNA and proteins.

Question 44

Where are ribosomes found?

Answer 44

In the cytoplasm and on the rough ER.

Question 45

What are the ribosome's functional sites?

Answer 45

A-site (aminoacyl), P-site (peptidyl), and E-site (exit).

Question 46

How does tRNA ensure accuracy in translation?

Answer 46

By matching its anticodon to the mRNA codon.

Question 47

What is the role of enhancers and silencers?

Answer 47

To regulate transcription by increasing or decreasing gene expression.

Question 48

What is polyadenylation?

Answer 48

The addition of a poly(A) tail to mRNA's 3' end for stability.

Question 49

What are transcription factors?

Answer 49

Proteins that control the rate of gene transcription.

Question 50

What is the function of ribosomal RNA (rRNA)?

Answer 50

It forms the core of the ribosome's structure and catalyzes protein synthesis.