Question

1. What purpose does the regulatory portion of the gene have?

2. In this simulation, the DNA molecule’s different strands are represented as different
colors one blue and one red. What is the significance of the two different
strands? Are they both used in transcription?

3. There are two required components to initiate transcription on the gene. What are they,
and where do they bind on the DNA strand?

4. How would you know if transcription has been successful?

5. How do negative transcription factors impact transcription?

6.Explain the difference in transcription between Gene 1 and Gene 2. Hypothesize the reason for the difference.

Answer 1

1. The coding region of a gene is used to make RNA molecules. This region is controlled by regulatory portions of the gene, which are located upstream of the coding region and determine when, where, and how much they are expressed. When it is time to express a gene (turn it on), when it's not the right time to express a gene (turn it off), lastly if expression needs to be enhanced (increase the amount of protein being produced).

2. In this diagram, one strand represents the coding strand, while the other represents the template strand. The template strand acts as a model for RNA polymerase to synthesize mRNA. The template strand is read by the polymerase, and complementary bases are added to form the mRNA.

3. Two components are required to initiate transcription, including RNA polymerase and transcription factors. In addition, there is also a promoter on the gene, which acts as a sort of "entrance" for the RNA polymerase to bind and begin transcription.

4. If transcription is successful, then you would expect to see RNA being produced.

5. In order to begin transcription, the RNA polymerase/general transcription factor must bind to the promoter. There are different types of transcription factors such as activators and repressors. If a repressor binds to the promoter, this effectively "blocks" the RNA polymerase.

6. There is a difference in transcription rates between Gene 1 and Gene 2 due to differences in regulatory elements and transcription factors. There are enhancers and activators that increase Gene 1's transcription, while silencers and repressors decrease Gene 2's transcription. Signals coming from inside or outside the cell, such as hormones, nutrients, or stress, may trigger these elements and factors.

Answer 2

Here are my answers to your questions:

The regulatory portion of the gene is a sequence of DNA that controls the expression of the gene. It may contain binding sites for transcription factors, which are proteins that activate or repress transcription. The regulatory portion of the gene may also include elements such as enhancers, silencers, and insulators, which can influence the rate and specificity of transcription12.

The two different strands of the DNA molecule are called the template strand and the coding strand. The template strand is the one that is used by RNA polymerase to make a complementary RNA transcript during transcription. The coding strand is the one that is not used by RNA polymerase, but has the same sequence as the RNA transcript (except for T instead of U). Both strands are important for transcription, but only one is directly copied34.

The two required components to initiate transcription on the gene are RNA polymerase and a promoter. RNA polymerase is the enzyme that synthesizes RNA from a DNA template. A promoter is a sequence of DNA near the start of a gene that signals RNA polymerase where to begin transcription. RNA polymerase binds to the promoter with the help of general transcription factors, which are proteins that recognize specific features of the promoter15.

Transcription has been successful if a complete and accurate RNA transcript has been produced from the DNA template. The RNA transcript can be detected by various methods, such as hybridization with a complementary DNA probe, electrophoresis on a gel, or sequencing1.

Negative transcription factors are proteins that repress transcription by binding to DNA and preventing RNA polymerase or other activators from accessing the gene. Negative transcription factors can regulate gene expression by turning off genes that are not needed or harmful in certain conditions67.

Gene 1 and Gene 2 have different transcription rates because they have different regulatory elements and transcription factors. Gene 1 has an enhancer and an activator that increase its transcription, while Gene 2 has a silencer and a repressor that decrease its transcription. These elements and factors may respond to different signals from inside or outside the cell, such as hormones, nutrients, or stress68.