BIOLOGY 305 Lecture Notes - Lecture 15: Trp Operon, Arabinose, Stem-Loop
Get access
Related Documents
Related Questions
Chapter 10
1.Outline the history of our knowledge on DNA up to Watson and Crick. What were the main contributions made by each researcher’s key experiment?
2.Explain the setup of the Hershey and Chase experiment, what would the results have been if protein was the genetic material?
3.Draw the structure of a DNA nucleotide, labeling each main component correctly. How does an RNA nucleotide differ?
4.If a section of double stranded DNA contains 19% Adenine, how much Thymine is present?
5.You are a researcher studying the genetic basis of heart attacks and have been working to determine the expression levels of different genes that might contribute to cancer formation. You obtain the DNA methylation status of five genes of interest (the data are shown in the table below). The plus (+) sign indicates the level of DNA methylation; more plus signs correlates with increased methylation levels.Based on this information which genes would you predict to have the highest rate of transcription?
Gene | Methylation levels |
1 | ++ |
2 | +++++ |
3 | +++ |
4 | ++ |
5 | + |
What are the characteristics of the 3 main DNA forms?
Chapter 11
What are the different types of chromatin?
What are the structures and important roles for telomeres and centromeres?
What are the differences found between eukaryotic chromosomes and mitochondrial?
Chapter 12
Explain each of the different models of replication.
If you grow a culture of bacteria in media with radioactive nucleotides so that all DNA in the cells include radioactive nucleotides and then place the bacteria in new non radioactive media. After two rounds of replication what proportion of the DNA molecules will contain radioactivity?
Summarize the similarities and differences between rolling-circle replication, theta replication and linear eukaryotic replication.
What are the functions of the different DNA polymerases found in eukaryotic cells?
Draw a replication fork and include all key components and orientations. (Leading/lagging strands, DNA helicase, RNA primer and DNA gyrase)
What is the Holliday model of recombination and what are the necessary steps?
Chapter 13
What are the different types of RNA and what roles do they play?
Describe the properties and functions of each of the RNA polymerases and how they differ depending on the organism.
Describe in detail the process and mechanisms of transcription in both prokaryotes and eukaryotes.
Chapter 14
What are the primary purposes of each of the three post transcriptional modifications that occur in eukaryotic cells.
What is alternative splicing and what role does it play in the cell?
How is ribosomal RNA processed after transcription?
How do siRNA and miRNA work, describe/draw out the process in detail.
QUESTION 10
If you can drink milk as an adult, it means that you have inherited a mutation in the promoter of your lactase gene (the gene that encodes the enzyme you need to break down lactose). Predict the effect of this mutation:
The mutation changes the number of domains in the enzyme, which makes it work more efficiently | ||
The mutation changes the amino acid sequence of the lactase protein | ||
The mutation increases the number of copies of the lactase gene that will be found in your genome | ||
The mutation changes whether the lactase sequence is found in an intron or exon | ||
The mutation affects the expression of the lactase gene |
1.2 points
QUESTION 11
A competitive inhibitor is decreasing the activity of an enzyme. Predict the effect of adding more substrate to the reaction.
The substrate will increase the reaction rate by binding to the allosteric site | ||
The substrate will increase the reaction rate by competing with the inhibitor for the active site | ||
The reaction rate will not change unless the inhibitor can be removed | ||
The enzyme adjusts its shape so that the substrate, but NOT the competitive inhibitor, can bind | ||
The substrate will bind to the competitive inhibitor and block its ability to bind to the enzyme |
1.2 points
QUESTION 12
What determines where in the genome a transcription regulator will bind?
Transcription regulators bind to the 5' UTR region of a gene | ||
Regulators bind via complementary base-pairing to certain DNA molecules | ||
Covalent bonds form between the transcription regulator and the atoms of the DNA backbone | ||
Every eukaryotic gene has a different transcription regulator that will bind to the 5' end of the gene | ||
Transcription regulators bind to specific DNA sequences via multiple weak non-covalent interactions |
1.2 points
QUESTION 13
What is the basic premise of cell theory?
DNA -> RNA -> protein | ||
All cells arise from pre-existing cells | ||
DNA provides the complete instructions to create a cell | ||
The identity of a cell is determined through gene expression patterns | ||
All cells contain the same four basic macromolecules |
1.2 points
QUESTION 14
What is the benefit of using BOTH the lac activator and the lac repressor to control gene expression?
Using both an activator and repressor enables cells to more accurately determine the amount of lactose available in the environment | ||
Enzymes to digest lactose are only made when energy is low and lactose is available | ||
The activator can override the inhibition of the lac operon by the repressor | ||
The repressor can control the enhancer, while the activator can control the promoter | ||
When neither the lac activator or repressor is present, expression of the lac operon is too high |
1.2 points
QUESTION 15
What is the histone code used for?
Phosphorylation and acetylation of DNA affect its ability to be compacted | ||
Changes to the sequence of DNA change whether DNA will wrap around histone proteins | ||
Covalent modifications of histones affect the ability of the transcription initiation complex to form | ||
Histones provide the codon sequences needed for translation to occur | ||
The histone code affects which amino acids will get added to a polypeptide |