1) Think about the bisubstrate reaction F + G -> H that can be catalyzed by an enzyme that 10) obeys Michaelis-Menten kinetics. Assume that [G] is so high that it is essentially unlimited.

Which one of the following scenarios is the one that can best be described as "first order with respect to F"?

=> [F] is three times lower than the Km.

Explain Why answer is [F] is three times lower than the Km.

14. Choose the answer and Explain Why
    If no ESI complex is ever formed, we can best conclude, based on our coverage of reversible 1inhibitors, that:

    1. A) the inhibitor is an uncompetitive inhibitor (but not the other two types)

    2. B) the inhibitor is a noncompetitive inhibitor (but not the other two types)

    3. C) the inhibitor could be either an uncompetitive or a noncompetitive inhibitor (but not the other type)

    4. D) the inhibitor is a competitive inhibitor (but not the other two types)

    5. E) the inhibitor could be either a competitive or an uncompetitive inhibitor (but not the other

       type)

3. Assume that a bacterial culture is grown on medium containing radioactive thymine until essentially all of the thymine in the DNA is radioactive. Then the bacteria with labeled T were washed and transferred to a medium containing nonradioactive T for one round of replication. Given the four double stranded sequences below, which one is likely to represent the replicated double stranded structure? Note: A,C,T,G represent typical nucleotides, and 3T represents labeled T.)

In PCR reactions, the only enzyme that is needed is a polymerase. Provide reasoning as to why the following essential replication enzymes/components are not needed:

Helicase

Topoisomerase

Ligase

Primase

Replication clamp

Due to system limitations you are attempting to clone a small bacterial gene using a poorly characterised bacterial plasmid. You know that the plasmid contains only two drug resistance markers (one for resistance to tetracycline, another for resistance to ampicillin). You have determined that the restriction enzymes EcoRI and BamHI each cut the plasmid only once while SauIII and RsaI cut the plasmid twice. You also have determined that the EcoRI and SauIII recognition sites are within the tetracycline resistance marker, but the BamHI and RsaI recognition sites are not within or even close to either drug resistance marker. You must use this particular vector: a. Which restriction enzyme(s) should you use and why? b. What will happen if you use the BamHI recognition site? What will happen if you use the RsaI recognition site? (Describe this with regards to the functioning of the drug resistance marker and which antibiotic(s) you should use in the media)

1. Regarding countercurrent mechanisms:
   1. List which structure(s) is/are responsible for establishing the concentration gradient in the renal medulla? Describe how this is accomplished. (5 points)
      1. Note: You do not need to describe the entire positive feedback loop, I am looking more simply for structures or structural modifications and functions of those structures. Do mention how the tubular fluid concentration changes and the interstitial fluid of the medulla is affected as a result.
   2. List which structure(s) is/are responsible for maintaining the concentration gradient in the renal medulla? Describe how this is accomplished. (2 points)
   3. ACE inhibitors (angiotensin converting enzyme inhibitors) are a popular class of drug that treats hypertension. Use your knowledge of the renin-angiotensin-aldosterone system to describe the physiological mechanism of how this medication works at the nephron and kidney level to reduce blood pressure. (3 points)
   4. Predict how ADH hypersecretion would affect the sodium concentration of the urine, and explain why. (2 points)

12) Imagine a pulmonary embolus breaking up and entering the pulmonary artery supplying blood to an entire lobe of the left lung, blocking 75% of the pulmonary arterioles in that lobe. Describe the effects on the arterioles and bronchioles in this lobe in response to this event.

13) Elevated potassium levels in the body (hyperkalemia) is a serious condition, resulting in a severely decreased ability for muscle fibers and neurons to reploarize. The adrenal cortex can respond to this. However, very high osmolarity shuts down this response. Explain this incongruity, by describing the response mechanism of the adrenal cortex. (6 pts)

16) ) A vaccine for Coronavirus is likely to take a longer time than imagined, because the most obvious target of the vaccine should be the external spike protein on the envelope of this enveloped virus. The cellular attachment protein on epithelial cells, which the virus binds to for entry into the epithelial cell, is known to be ACE2, a receptor enzyme. Explain why the production of a vaccine targeting the coronavirus spike protein (S1), is not likely to be successful.

3) You have four tubes containing the same DNA at the sameconcentrationin each tube (pH 7.5) but under different environmental conditions (listed below).  The T_Mfor this DNA molecule is 78°C at physiological salt conditions (~100 mM NaCl):

1. DNA in an aqueous solution that has been digested completely to nucleotideswith DNAse I enzyme.

2. DNA in an aqueous solution containing no salt and has been heated to 78°C.

3. DNA in an aqueous solution containing physiological concentrations of salt and heated to 78°C.

4. DNA in an aqueous solution containing physiological concentrations of salt and is heated only to 37^oC.

Match the samples above with their corresponding OD₂₆₀readings.  Next, explain your reasoning for each of the matches you made.  (For example, “The DNA in sample (a) gives the highest OD reading because…”).

• OD₂₆₀= 1.01 à

• OD₂₆₀= 0.195 à

• OD₂₆₀= 0.713 à

• OD₂₆₀= 0.421 à

3) You have four tubes containing the same DNA at the same concentration in each tube (pH 7.5) but under different environmental conditions (listed below). The TM for this DNA molecule is 78°C at physiological salt conditions (~100 mM NaCl): a. DNA in an aqueous solution that has been digested completely to nucleotides with DNAse I enzyme. b. DNA in an aqueous solution containing no salt and has been heated to 78°C. c. DNA in an aqueous solution containing physiological concentrations of salt and heated to 78°C. d. DNA in an aqueous solution containing physiological concentrations of salt and is heated only to 37oC. Match the samples above with their corresponding OD260 readings. Next, explain your reasoning for each of the matches you made. (For example, “The DNA in sample (a) gives the highest OD reading because…”). • OD260 = 0.620 • OD260 = 0.960 • OD260 = 0.475 • OD260 = 0.271

1. What are some of the major challenges for non-Islamist advocates of democratization and human rights, in the aftermath of the Arab uprisings, especially with regard to political engagement with Islamist groups and political parties?

2. In Egypt, what strategies and methods of political engagement, intervention, or disruption (violent and non-violent) did the Muslim Brotherhood adopt since the 1970s?

1. Can you place the
magnifying glass where the image is magnified even more. If there is such a place, explain.

2.Compare the way a camera works to the way the human eye works. What are the similarities and
differences in the way that each performs its function. In particular, compare the way the camera
and eye focus objects located at different distances.