The H2 antagonist burimamide showed poor bioavailability in clinical trials.

(i) Define the term bioavailability. In your answer, distinguish bioavailablility
from bioactivity.
(ii) Protonation of the imidazole ring was identified as a reason for the low
bioavailability of burimamide. Explain, using appropriate structures, why
thiaburimamide, which features a sulfur atom in the alkyl chain, led to
increased bioavailability.

(iii) Thiaburimamide, also led to a modest increase in bioactivity. Propose a
reason for this increase in activity.

Your project should be on temperature adaptation or thermostability of proteins.

For a temperature adaptation project select an ectothermic organism with sub-species living in different climates. You will then focus on one protein, preferably an enzyme, for which you need to find amino acid sequences (one for each sub-species). You also need at least one crystal structure of this protein with enough sequence similarity to your selected amino acid sequences to make it feasible to create homology models. Finally, you will make comparisons between the structures or homology models while focusing on structural features that promote protein stability.

OR

For a thermostability project select a thermophilic organism (for example a bacterium thriving in a hot spring) and one protein, preferably an enzyme for which a crystal structure is already available. Next, you will need to search for crystal structures and/or amino acid sequences of your selected protein in other non-thermophilic organisms so that you can make comparisons between the crystal structures (or homology models). Aim to identify structural features that promote the thermostability of the protein from the thermophilic organism.

State the parameters of your project:

Species:

Protein(s):

PDB ID:

Confirm that you will have access to protein sequences and at least one protein structure (as a template for homology modeling) so that you can carry out your project. Post the access codes for the sequences and the PDB-ID(s) here:

Make a list of structural features that promote protein stability:

Note: Except the isocitrate dehydrogenase protein.

example like in the below articke

Most stars, including our own sun, undergo nuclear fusion using hydrogen as the primary fuel source. Some stars, however, use helium, carbon, or other elements as their primary fuel, and all stars will have at least trace amounts of many other elements. Describe a way you can use the concepts of atomic spectroscopy to determine the elemental composition of stars.

When Chlorine gas is used to disinfect drinking water, it hydrolyzes with the water to form hypochlorous acid (HOCl, pKa = 7.54), which is a powerful disinfectant. However, when the acid dissociates to its conjugate base, it becomes a less effective disinfectant. The disinfection power of the acid is 88 times better than its conjugate base, OCl-, on a per-mole basis.

1. Calculate the mass of hypochlorous acid you would need to add to 1 liter of water at pH = 13 to get the same disinfectant power you would get by adding 1 g HOCl to 1 liter of water at pH = 2.0.

How many grams of dry NH4Cl need to be added to 1.80 L of a 0.600 M solution of ammonia, NH3, to prepare a buffer solution that has a pH of 8.96? Kb for ammonia is 1.8×10−5

Explain in detail endothermic and exothermic energy and how it is in chemistry and provide examples of each

A) Explain the general responses of ceramics, metals and polymers to mechanical and electrical loads in terms of both primary and secondly chemical bonds

B) Classify the following materials as a polymer, metal, ceramic, or composite: Boron Nitride, Bricks, Plexiglas, Concrete and Manganese.

Pre-lab questions for a Saponification lab:

A student assembled the reflex apparatus. Later the joint was seized and the RBF had to be broken to disassemble the apparatus. What was the cause of this? How could it have been prevented?

Filtering the soap using a washcloth exposes your hands to a very basc solution. What should you be doing to protect your hands from basic hydrolysis?

Thank you!

Your lab is supplied with 1.500 F solutions of HCL, NaOH, acetic acid, (Ka = 1.75x10^-5) sodium acetate. Prepare a 400.0mL o a 0.1000M acetate buffer: pH 4.622 using specified reagents

a) 1.000 F acetic acid and 1.000 F sodium acetate

b) 1.000 F sodium hydroxide

c) 1.000 F sodium acetate and 1.000F HCl

Please show all work!

11.

A 150.0 mL solution of 2.713 M strontium nitrate is mixed with 220.0 mL of a 2.401 M sodium fluoride solution. Calculate the mass of the resulting strontium fluoride precipitate.

mass: g

Assuming complete precipitation, calculate the final concentration of each ion. If the ion is no longer in solution, enter a 0 for the concentration.

[Na+] M

[NO−3] M

[Sr2+] M

[F−] M

Complete the stoichiometry of each reaction, making sure both stoichiometry and charge balance are correct. That is, find the values of the coefficients A, B, C, etc., for each reaction. Show your work and explain your reasoning. [2 Points each]

(a) Oxidation of nitrite to nitrate (a chemoautotrophic process): A·O2 + B·NO2- = C·NO3-

(b) Oxidation of organic matter using nitrite (a step of denitrification, a heterotrophic reaction):

A·CH2O + B·NO2- + C·H+ = D·CO2 + E·N2 + F·H2O
(c) Oxidation of ammonium with nitrite (anammox, a chemoautotrophic process):

A· NH4+ + B·NO2- = C·N2 + D·H2O

[Hint: start by writing the 2 half-reactions for each full reaction, including the number of electrons produced by the oxidation half-reaction, and the numbers of electrons required for the reduction half-reaction. Then balance H+ and H2O if required by stoichiometry, and sum the half reactions, each multiplied by the factor required to have the same number of electrons produced and consumed. End by simplifying terms present in both sides.]

A sample of concrete with a density of 2.35 g/cm³ has a hydrogen content of 0.0085 weight fraction. a) what is the atom density of hydrogen in the concrete? b) what is the atom density of hydrogen in water at room temperature? c) how do these numbers compare (comment)?

Silicon dioxide and solid carbon react to form solid silicon and carbon monoxide.What is oxidized?

2. How would Evelyn Effec affect the products formed from the dehydration of 2-methylhexanol (My product is 1-methylcyclohexene)? How could you modify the experiment to check for the Evelyn Effect?

Natural gas is primarily methane, CH4, and is used to heat homes. A typical home is approximately 2000 ft2 and the ceilings are 8 ft high. The following data may be helpful: The heat capacity of air is 1.01 J/g·K and the and the enthalpy of combustion of methane is -890.8 kJ/mol. Assume that the molecular weight of air is the same as nitrogen, its major component. How many grams of methane are required to raise the temperature in the home from 35°F to 66°F? How many grams of CO2 does this reaction produce?