Gene Regulation
What are cells 2 levels of metabolic control?
Cells can adjust the activity of enzymes that are currently present such as feedback inhibition and cells can adjust the production of certain enzymes such as turning on and off transcription.
Explain Focused Promoters.
Focused promoters are located in a specific nucleotide and are found in simpler eukaryotes. They are usually associated with genes that have high regulated transcription levels.
Unit Factors in pairs states that genetic characters are controlled by unit factors existing in pairs in individual organisms. For each character, an organism inherits a pair of alleles, one from each parent.
What is the product rule?
The product rule helps figure out the probability that two or more independent events will occur at the same time is equal to the product of their individual probabilities.
What is a domain?
A domain is a cluster of amino acids that do not have protein that perform a specific function.
What does the repressor do?
The repressor prevents gene transcription.
Explain Dispersed Promoters.
Dispersed promoters are located in a general area, about 50-100 nucleotide region. They are more commonly found in more complex eukaryotes and are associated with genes that are constantly expressed.
Explain Dominance and Recessives
Dominance and Recessives states that an allele is dominant or recessive. When two unlike unit factors responsible for a single character are present in a single individual, one factor unit is dominant to the other, and the other is said to be recessive.
What is the sum rule?
The sum rule helps look at the probability that one of two or more mutually exclusive outcomes will occur is the sum of the probabilities of the possible outcomes.
What must CAP be activated by?
CAP must be activated by cyclic adenosine monophosphate also known as cAMP.
What does the operon do and what is it consisted of?
The operon is a stretch of DNA that is needed to produce a protein. It controls gene expression in prokaryotes. It is made up of the operator, the promoter and the genes that they control.
What is the difference between silencers and enhancers?
Silencers repress the level of transcription initiation while enhancers are necessary for maximal transcription levels (increase).
Segregation
Segregation states that during the formation of gametes, the paired unit factors separate, or segregate randomly so that each gamete received one or the other with equal likelihood. In other words, two alleles for a heritable character separate during gamete formation and end up in different gametes.
How do you find the number of different gametes can be produced by each parent?
2^n
What is the regulatory site?
The regulatory site is the promoter and the operator and is found on the same DNA strand as the structural genes.
What are constitutive enzymes?
Constitutive enzymes are enzymes that are continuously produced and are created no matter what.
What is the enhancesome?
The enhancesome is a complex where activators bind to enhancers and interact with proteins called coactivators. It helps initiation start more efficiently.
Explain Independent Assortment
Independent Assortment states that during gamete formation, segregating pairs of unit factors assort independently of one another. When there are two traits, whatever goes into the gamete will not affect the sorting of a different gene.
When you have two heterozygous parents, what is the expected phenotypic ratio?
3:1
What is a test cross?
A test cross is a cross between the dominant phenotype and the recessive phenotypes. This will help determine the genotype of the dominant parent when it is not known.
What is the difference between negative and positive control in gene regulation?
Negative gene control is when the gene is always expressed unless an active repressor binds to the operon and turns it off. Positive gene control is when the gene is always off unless an active form of an activator binds to the operon and turns it on.
What are spliceopathies?
Spliceopathies are defects in the regulation of RNA splicing. Examples include Huntington’s Disease and Fragile-X syndrome.
What is the purpose of the Hardy-Weinberg Equilibrium?
The Hardy-Weinberg Equilibrium helps describe a hypothetical population that is not evolving. Therefore, the gene pool remains constant and does not change (evolve) over time. There must be no mutations, random mating, no natural selection, a very large population size and no gene flow.
When you have two heterozygous parents, what is the expected genotypic ratio?
1:2:1
Describe attenuation in detail using the trp operon.
Antennation is an alternate regulatory mechanism for trp. When transcription has already started, attenuation can repress the expression of the operon only if trp is present. Transcription will stop before it reaches the trp structural genes. It can form two different loops, Terminator and Antiterminator. When the trp levels are high, terminator is formed, when trp levels are low, antiterminator is formed.