Misc. Chemistry
Amino Acids
Inhibitors
Enzymes as catalysts
Catalytic mechanisms
100
  1. Theobromine (C7H8N4O2) is a molecule found in chocolate that is toxic to dogs. The amount a dog can eat depends on its weight, for my 24 lb corgi 7.75 X 10-4 moles or more of theobromine can be dangerous. If I used 2 bags of chocolate chips in the cookie dough, with each bag weighing around 340.19 g and containing 0.1552% theobromine by weight, could my dog eat the whole batch of cookies? Answer must include the theobromine content.

No (0.00586 moles)

100

What is the name and three letter abbreviation of the following amino acid



Asparagine (ASN)

100

What are the three types of inhibitors?

Competitive, uncompetitive, mixed

100
Enzymes affect __ not ___

Enzymes affect kinetics not thermodynamics

100

What are the four mechanisms you need to have memorized?

Carbonic, anhydrase, RNase, chymotrypsin, lysozyme

200

How many chiral centers does this molecule have?

5

200

Draw tryptophan


200

What does each type of inhibitor interact with?

Competitive: active site

Uncompetitive: ES complex

Mixed: both

200

Graph a first order reaction with and without an enzyme? (hint: rate on y-axis, concentration on x-axis)

linear relationship for without enzyme, logarithmic with

200

What is the catalytic triad in chymotrypsin? Draw out nucleophile generation

His57, Ser195, Asp102.


300

Hg2Br2 is a slightly soluble solid that dissociates according to the reaction:

If the concentration of Hg22+ in a saturated solution of Hg2Br2 at 25°C is found to be 2.44 × 10−8 M. What is the value of Ksp for this salt?

5.81 X 10^-23

300

Draw the two sulfur-containing amino acids


300

How does each inhibitor impact Vmax and Km?

Competitive: no impact on Vmax, Km increases

Uncompetitive: both decrease

Mixed: Vmax decreases, Km depends

300

How does an increase in Kd affect substrate affinity?

Lower affinity

300

What are the classifications for the two intermediates in the proposed mechanisms for lysozyme?

Covalent and carbocation

400
  1. You are excited to start working in your garden and you want to sow your lettuce seed today, but in order to do so the temperature has to be below 26.67 °C or the seed will go dormant. Unfortunately, you woke up late and missed the beginning of the weather forecast. All you heard was that the dew point is 21.24 °C and the relative humidity is 75%. What is the temperature today?

Given:

299.178 K or 26.03 ℃

400

How many carbons and nitrogens are in the side chains of lysine and arginine?

4 carbons in both. 1 nitrogen in lysine, 3 in arginine

400

Draw the Lineweaver-Burk plots depicting the effects of each type of inhibitor


400

When [ET]=4 nanomolar and Vmax=1.6 micromolar/seconds, what does kcat equal?

400 1/sec

400

Draw out the mechanism for the generation of the catalyst in a carbonic anhydrase reaction

See physical copy

500

Calculate ΔS (for the system) when the state of 2.00 mol diatomic perfect gas molecules, for which Cp,m = 7/2 R, is changed from
25 °C and 1.50 atm to 135 °C and 7.00 atm. 


-2.12 J/K*mol



500

What are the polar neutral amino acids?

Tyrosine, Serine, Threonine, Asparagine, Glutamine, Cysteine.

500

Write out the relationship between alpha and Ki

alpha= 1+ (concentration of inhibitor/Ki)

500

At what substrate concentration would an enzyme with a Kcat of 30.0 1/sec and a Km of 0.0050 M operate at 1/4 of its maximum rate?

1.7x 10^-3 M

500

Draw out the mechanism for the hydrolysis of a phosphodiester bond via RNase