Protein Synthesis

Question 1

What is the central dogma of molecular biology?

Answer 1

DNA is transcribed into RNA, which is translated into proteins.

Question 2

Where in the cell does transcription take place?

Answer 2

Nucleus.

Question 3

What polymer is synthesized during transcription?

Answer 3

RNA.

Question 4

How does RNA polymerase recognize the start of a gene during transcription?

Answer 4

By binding to the promoter region of DNA.

Question 5

What parts make up the transcription initiation complex?

Answer 5

RNA polymerase, transcription factors, and the promoter region.

Question 6

Where on the DNA strand does transcription initiation form?

Answer 6

At the promoter region.

Question 7

What is the role of hydrogen bonding in transcription?

Answer 7

It stabilizes the DNA-RNA hybrid during transcription.

Question 8

What is the base-pair rule for DNA and RNA?

Answer 8

A pairs with U, T with A, C with G, G with C.

Question 9

Why is the stability of DNA templates crucial in somatic cells that do not divide?

Answer 9

To maintain the integrity of genetic information over time.

Question 10

How do single DNA strands serve as templates for transcription without changing the DNA?

Answer 10

RNA polymerase creates a complementary RNA strand without altering the DNA.

Question 11

What happens during transcription?

Answer 11

RNA polymerase synthesizes an RNA strand using the DNA template.

Question 12

What happens during RNA splicing?

Answer 12

Introns are removed, and exons are joined to form mature mRNA.

Question 13

How is mRNA transported?

Answer 13

It is transported through nuclear pores from the nucleus to the cytoplasm.

Question 14

What happens during translation?

Answer 14

mRNA is decoded by ribosomes to synthesize a polypeptide chain.

Question 15

What is the goal of translation?

Answer 15

To synthesize polypeptides from mRNA’s codon sequence.

Question 16

How is the amino acid sequence determined during translation?

Answer 16

By the matching of mRNA codons with tRNA anticodons.

Question 17

What happens when a ribosome encounters a stop codon during translation?

Answer 17

Release factors terminate translation, and the polypeptide is released.

Question 18

What is the structure of a ribosome?

Answer 18

It consists of large and small subunits, with mRNA and tRNA binding sites.

Question 19

What is the role of tRNA during translation?

Answer 19

It carries amino acids and matches codons with its anticodon.

Question 20

How does tRNA know which amino acid to attach?

Answer 20

By using base-pairing rules with the mRNA codon.

Question 21

Why are humans different despite having the same genetic code?

Answer 21

Genetic variations, mutations, and regulatory differences lead to diverse traits.

Question 22

Do all DNA sequences code for proteins?

Answer 22

No, non-coding regions and regulatory elements do not code for proteins.

Question 23

What is an enhancer in gene expression regulation?

Answer 23

A DNA sequence that binds activators to increase transcription.

Question 24

What is the function of silencers in gene expression?

Answer 24

To inhibit transcription by binding repressors.

Question 25

What is the role of the promoter in gene expression?

Answer 25

It is a DNA region where RNA polymerase binds to start transcription.

Question 26

How does temperature affect gene expression?

Answer 26

It can impact traits like skin pigment through regulatory gene expression.

Question 27

What is the primary function of morphogens during embryonic development?

Answer 27

They regulate gene expression to control body patterning.

Question 28

How does the ribosome catalyze peptide bond formation?

Answer 28

It uses its binding sites to align mRNA and tRNA, facilitating protein synthesis.

Question 29

What are post-translational modifications in protein processing?

Answer 29

Modifications like phosphorylation and glycosylation to activate or stabilize proteins.

Question 30

How does a mutation in the hemoglobin gene cause sickle cell anemia?

Answer 30

It leads to abnormal hemoglobin, which distorts red blood cells.

Question 31

What is the only difference between the nucleotide sequence of the normal hemoglobin gene and the sickle cell hemoglobin gene?

Answer 31

The only difference is a point mutation where glutamic acid is replaced by valine at the 6th amino acid.

Question 32

What happens during the initiation stage of translation?

Answer 32

mRNA binds to the small ribosomal subunit, and tRNA binds to the start codon (AUG) in the P site.

Question 33

What happens during elongation in translation?

Answer 33

tRNA binds to the A site, a peptide bond forms, and the ribosome moves one codon along the mRNA.

Question 34

What occurs during termination in translation?

Answer 34

Translation stops when a stop codon is reached.

Question 35

What is the central dogma of molecular biology?

Answer 35

It describes the flow of genetic information from DNA to RNA to protein.

Question 36

How does CRISPR-Cas9 work as a genetic medicine?

Answer 36

CRISPR-Cas9 edits DNA by inducing cuts at specific sequences, allowing for gene modification.

Question 37

How does gene therapy treat genetic disorders?

Answer 37

Gene therapy delivers a functional gene to replace or supplement defective ones, correcting genetic mutations.

Question 38

What is the role of gene switches in genetic medicine?

Answer 38

Gene switches control gene expression by turning genes on or off as needed.

Question 39

What is exon skipping and how does it correct genetic mutations?

Answer 39

Exon skipping removes defective exons during RNA splicing to restore the reading frame and produce a functional protein.

Question 40

How does RNA interference work as a genetic medicine?

Answer 40

RNA interference silences disease-causing genes by degrading specific mRNA molecules.

Question 41

What are small molecule drugs and how do they treat genetic diseases?

Answer 41

Small molecule drugs target specific proteins or cellular processes, modulating activity to treat diseases.

Question 42

What is the significance of 5' to 3' transcription?

Answer 42

RNA polymerase reads DNA from 5' to 3' to ensure accurate RNA synthesis.

Question 43

What does 5' to 3' translation refer to?

Answer 43

It refers to the direction ribosomes read mRNA to synthesize a polypeptide chain.

Question 44

What role do promoter regions play in gene expression?

Answer 44

Promoter regions initiate transcription by guiding RNA polymerase to the correct gene.

Question 45

How do non-coding regulators of gene expression function?

Answer 45

They control gene expression by interacting with transcription factors to regulate transcription timing and level.

Question 46

What is the function of genes for rRNA and tRNA?

Answer 46

rRNA forms ribosomes, while tRNA delivers amino acids during protein synthesis.

Question 47

What is RNA splicing?

Answer 47

RNA splicing removes introns and joins exons to form mature mRNA.

Question 48

What is the function of the spliceosome?

Answer 48

The spliceosome removes introns and joins exons to produce functional mRNA.

Question 49

How does alternative RNA splicing increase protein diversity?

Answer 49

It selects different exons during splicing to produce various protein isoforms from one gene.

Question 50

What happens after the small ribosome subunit reaches the start codon?

Answer 50

The initiator tRNA binds to the AUG codon in the P site, marking the start of translation.

Question 51

What are the three tRNA binding sites on the ribosome?

Answer 51

A site binds new tRNA, P site holds the growing chain, and E site releases the empty tRNA.

Question 52

How do amino acid properties influence protein folding?

Answer 52

Hydrophilic amino acids face outward, hydrophobic ones face inward, forming protein structure.

Question 53

What is the first step in the modification of pre-proinsulin?

Answer 53

The signal sequence is removed from pre-proinsulin, converting it to proinsulin.

Question 54

How is proinsulin converted into mature insulin?

Answer 54

C-peptide is removed from proinsulin, forming functional insulin with disulfide bonds.

Question 55

Why is recycling amino acids important for a functional proteome?

Answer 55

Recycling ensures a constant supply of amino acids for protein synthesis.

Question 56

What is the role of proteasomes in protein breakdown?

Answer 56

Proteasomes degrade proteins tagged with ubiquitin, releasing amino acids for reuse.

Question 57

How does proteasome-mediated amino acid recycling contribute to protein synthesis?

Answer 57

Proteasomes break down proteins into amino acids, which are reused to synthesize new proteins.

Question 58

What happens to introns and exons during RNA splicing?

Answer 58

Introns are removed, and exons are joined to form the mature mRNA.

Question 59

How is the open reading frame preserved during RNA splicing?

Answer 59

The correct sequence of exons is maintained, ensuring accurate translation into protein.

Question 60

How does the 5' cap and poly-A tail assist mRNA?

Answer 60

They provide stability, aid in mRNA transport, and protect against degradation.