1. Fill in the table below concerning chromatin modification.

2. A moth census on Wooded Island counted 100 black (BB) moths, 40 gray (Bb) and 60 white (bb) moths. What are the genotypic frequencies? What are the allelic frequencies? Is the population in Hardy-Weinberg equilibrium?   

Ill Rate High

A variety of plants are used as folk medicine in the treatment of hypertension.
Laboratory analyses show that a purified extract from one of these plants decreases
production of aldosterone in an animal model.
Complete the sentences below to explain how this anti-hypertensive plant extract might
work. In each case indicate the enzyme, hormone or receptor targeted and explain how the
action of the extract on this target would result in reduced aldosterone production.
A. The purified extract inhibits…
(60-word limit)
B. The purified extract blocks…
(60-word limit)

TRUE or FALSE? Please explain each answer!

a) The more negative the ∆H value of a reaction the faster it is.

b) The more negative the ∆G value of a reaction the faster it is.

c) If you compare two reactions, the one with the lowest activation energy is faster (tricky!)

d) A catalyst is a substance that lowers the ∆G value of a reaction so it becomes more spontaneous.

e)Enzymes are proteins that lower the activation energies of reactions in the cell.

f) ATP hydrolysis is thermodynamically favorable but the reaction is slow in the absence of the enzyme specialized in catalyzing this reaction.

Considering the Metabolic pathways of Pseudomonas aeruginosa:

A. Briefly evaluate the metabolism of the organism. How do they make PMF, ATP and reducing power? Do they have a broad or a narrow metabolic capacity?

B. How would deleting the TCA cycle affect this organism?

C. What about a mutation in the quinol binding site of the bc1 complex (Complex III) so that it could not accept a quinol?

D. What about a mutation in the gene that encodes glyceraldehyde-3-P dehydrogenase (the enzyme that catalyzes the oxidation of G-3-P)?

The clinical symptoms of two forms of galactosemia show radically different severity.

1. Deficiency of galactokinase
2. Deficiency of UDP-glucose:galactose 1-phosphate uridylyltransferase

Although both types produce gastric discomfort after milk ingestion, deficiency of the transferase also leads to liver, kidney, spleen, and brain dysfunction and eventual death.

Explain, what products accumulate in the blood and tissues with each type of enzyme deficiency? (3 point)

List the symptoms for each type of deficiency. (3 point).

Explain which of these products is more toxic and why?

Question:

DNA polymerase III is the main DNA-synthesizing enzyme in bacteria. Describe how it carries out its role of elongating a strand of DNA.

Answer:

DNA pol III determines which free nucleotide triphosphate is complementary to the base being copied. DNA pol III catalyzes phosphodiester bond formation between the alpha phosphate of the incoming nucleotide triphosphate and the 3’ hydroxyl group of the last nucleotide added to the strand.

Can someone please explain this step by step in a dumbed down version? Thank you!

A protonated histidine residue in the active site of aspartate transcarbamoylase, ATCase, is thought to be important in stabilizing the transition state of the bound substrate.

A) Sketch a graph showing the pH dependence of the catalytic rate, assuming that this interaction is essential and dominates the pH-activity profile of the enzyme. Provide the biochemical basis for your graph.

B) The ATCase mechanism is known to proceed via an ordered mechanism. Draw a Cleland notation diagram showing how this reaction proceeds. Abbreviate the second substrate as CP. Two products are formed.  

Thank you!

Address the following (~200-300 words total):

1. How does a normal cell become a cancerous cell? What has to happen to it?
2. The video resources in the MasteringBio assignment focus on the telomerase enzyme role in cancer development. Explain the connection between telomerase activity and cancer.
3. The textbook essay focuses on a mutation that can happen in white blood cells that leads to blood cancer, leukemia. Explain the connection between BCR-ABL mutation and leukemia.
4. Propose a scenario where telomerase and BCR-ABL proteins are active in the same cell.

1. What would be the concentration of a 16 mM solution after 4–fold dilution?

2. To make 100 mL of a 5% (w/v) glucose solution, how much glucose would you use?

3. How much NaCl would you add to make an aqueous 10% (w/v) NaCl solution with a final volume of 500 mL?

A 1X reaction buffer contains the following concentrations of each compound. Calculate the amount of each compound (in g) that would be needed to make 100 mL of a 5x stock solution.

You have a protein sample at a concentration of 50 mg/mL. You make a 1:5 dilution of this sample and then take out a 200 µL aliquot. How many mg of protein are contained in this aliquot?

You are digesting an unknown plasmid with the restriction enzyme MboII. Use the table below to calculate how much of each component you need to add to your digest for a final volume of 20 µL.

1. One of the roles of the liver is to maintain a blood glucose level between 70 – 120 mg/dL (roughly 3.8 – 6.7 mM). Several factors are involved in the fact that liver cells (hepatocytes) respond differently than other cell types; on of those factors is differential expression of hexokinase isoforms. Most cells express hexokinase I; the liver primarily uses isoform IV, more commonly referred to as glucokinase. The table below summarized some of the differences between these isoforms.

a. Define the term isoform. How can isoforms of the same enzyme be differentially regulated?

b. Explain the physiological logic behind the differences between these isoforms.

c. Using the data provided, sketch a plot of enzyme rate as a function of glucose concentration for both isoforms on a single set of axes. Include curves for each isoform in the presence and absence of glucose-6-phosphate. Explain the reasoning behind your curves, including any decision as the type of inhibition exhibited by glucose-6-phosphate.

d. Hexokinase is also inhibited by ATP. Explain why this makes sense and draw a curve for hexokinase in the presence of ATP on the graph above.