MCB 2050 Lecture Notes #1 Questions and
Answers 100% Solved
How is gene expression regulated by peptide hormone? Correct Answ_Peptide hormone, a
linear chain of amino acid, is unable to permeate the cell membrane.
1. The peptide hormone attaches to membrane-bound receptor proteins and activates.
2. Hormone/receptor complex activates a cytoplasmic protein signal.
3. Cytoplasmic protein transducts a signal to the nucleus.
4. Signal induces a transcription factor.
5. Bound transcription factor stimulates transcription.
When a hormone transmits a signal to a cell, what is this called? Correct Answ_Signal
transduction.
What is significant about the heat-shock protein in its evolutionary history? Correct Answ_It
is a highly conserved polypeptide found in both eukaryotes and prokaryotes.
What types of interactions regulate transcription? Correct Answ_Protein-protein and protein-
DNA interaction.
,What gene transcribes for heat shock protein? Under what environmental condition? Correct
Answ_In Drosophila, HSP70 gene encodes for the heat-shock protein. In order to induce
transcription, the temperature must exceed 33 degrees celsius.
But how is this gene induced? Correct Answ_By HSTF (protein), a mediating polypeptide
which will undergo phosphorylation when heat stressed found in the nuclei. It will bind
specifically to the Heat-Shock Response Elements (HSE/DNA or RNA) upstream which will
activate transcription.
Note HSTF! Where is it found? When it binds to HSE, what is this binding called? Correct
Answ_Remember that HSTF exists in the cytoplasm in an inactivated form until it is
phosphorylated. It is activated once it binds with HSE, transported by a chaperone into the
nucleus. This overall process is called Induction.
Gene regulation at the transcriptional level is the most important step of gene regulation. How is
DNA regulated? Correct Answ_By promoters and enhancers.
How is DNA protein regulated? Correct Answ_By basal (promoter) and special (enhancer)
transcription factors.
, Where are promoters found on the transcript? Correct Answ_Always found upstream.
Protein-protein interaction.
Considering enhancers, why are they important in DNA regulation? Why are there so many
enhancers? Correct Answ_Enhancers play a big role in regulating and inducing transcription.
Enhancers are tissue specific.
What are the three things enhancers do? (BAR) Correct Answ_1. Binding site for
transcription activators and suppressors.
2. Assemble transcription activation complex and increase rate of transcription.
3. Regulates inducible and tissue-specific gene expression
What are the three distinct features of enhancers? Correct Answ_1. They act over large
distances
2. Their influence on gene expression is independent of orientation (can be inverted)
3. Effects are independent of gene position. Even at introns, they have profound effects on gene
expression.
Answers 100% Solved
How is gene expression regulated by peptide hormone? Correct Answ_Peptide hormone, a
linear chain of amino acid, is unable to permeate the cell membrane.
1. The peptide hormone attaches to membrane-bound receptor proteins and activates.
2. Hormone/receptor complex activates a cytoplasmic protein signal.
3. Cytoplasmic protein transducts a signal to the nucleus.
4. Signal induces a transcription factor.
5. Bound transcription factor stimulates transcription.
When a hormone transmits a signal to a cell, what is this called? Correct Answ_Signal
transduction.
What is significant about the heat-shock protein in its evolutionary history? Correct Answ_It
is a highly conserved polypeptide found in both eukaryotes and prokaryotes.
What types of interactions regulate transcription? Correct Answ_Protein-protein and protein-
DNA interaction.
,What gene transcribes for heat shock protein? Under what environmental condition? Correct
Answ_In Drosophila, HSP70 gene encodes for the heat-shock protein. In order to induce
transcription, the temperature must exceed 33 degrees celsius.
But how is this gene induced? Correct Answ_By HSTF (protein), a mediating polypeptide
which will undergo phosphorylation when heat stressed found in the nuclei. It will bind
specifically to the Heat-Shock Response Elements (HSE/DNA or RNA) upstream which will
activate transcription.
Note HSTF! Where is it found? When it binds to HSE, what is this binding called? Correct
Answ_Remember that HSTF exists in the cytoplasm in an inactivated form until it is
phosphorylated. It is activated once it binds with HSE, transported by a chaperone into the
nucleus. This overall process is called Induction.
Gene regulation at the transcriptional level is the most important step of gene regulation. How is
DNA regulated? Correct Answ_By promoters and enhancers.
How is DNA protein regulated? Correct Answ_By basal (promoter) and special (enhancer)
transcription factors.
, Where are promoters found on the transcript? Correct Answ_Always found upstream.
Protein-protein interaction.
Considering enhancers, why are they important in DNA regulation? Why are there so many
enhancers? Correct Answ_Enhancers play a big role in regulating and inducing transcription.
Enhancers are tissue specific.
What are the three things enhancers do? (BAR) Correct Answ_1. Binding site for
transcription activators and suppressors.
2. Assemble transcription activation complex and increase rate of transcription.
3. Regulates inducible and tissue-specific gene expression
What are the three distinct features of enhancers? Correct Answ_1. They act over large
distances
2. Their influence on gene expression is independent of orientation (can be inverted)
3. Effects are independent of gene position. Even at introns, they have profound effects on gene
expression.
