AAMC Scored FL 2 Review Flashcards
I. Remember AMC is attached to the peptide on the carboxyl side.
The COO- group attacks the amine, and forms an amide linkage for attachment.
What is the formula to calculate Kcat of an enzyme?
Compared to the concentration of the proteasome (2nM),by what factor was the substrate concetration(100uM) larger?
5x104
Four organic compounds: 2-butanone, n-pentane, propanoic acid, and n-butanol, present as a mixture, are separated by column chromatography using silica gel with benzene as the eluent. What is the expected order of elution of these four organic compounds from first to last?
A: n-Pentane->2-butanone->n-butanol->propanoic acid
B: n-Pentane->n-butanol->2-butanone ->propanoic acid
C: Propanoic acid->n-butanol->2-butanone->n-pentane
D: Propanoic acid->2-butanone->n-butanol ->n-pentane
A: n-Pentane->2-butanone->n-butanol->propanoic acid.
The compounds have similar MWs, so will elute based on polarity. Silica gel is the stationary phase(polar), and benzene is the eluent(non-polar).
The most non-polar compounds will elute first. (np)Alkenes->ketones->alcohols->COOHs(p).
What is the net charge of sT-loop(KTFCGPEYLA) at pH 7.2?
A:-2
B: -1
C: 0
D: +1
C: 0
The N-terminus will be + charged and the COO- will have a negative charge. In addition, K will carry a + charge and E will have a negative. All the others are neutral.
What type of phosphate is involved in a phosporyl transfer within kinases?
A: alpha-phosphate
B: beta-phosphate
C: gamma-phosphate
D: Delta-phosphate
C: Gamma-phosphate
Consider the equation below…
Would th_e concentration of [Cu(NH3)4]2+ increase_ if the equilibrium were disturbed by adding HCL?
A: Yes, b/c the equilibrium in Equation 1 would shift to the left.
B: No, b/c the quilibrium in Equation 1 would shift to the left.
C: Yes, b/c the equilibrium in Equation 1 would shift to the right.
D: No, b/c the equilibrium in Equation 1 would shift to the right.
B: No, b/c the equilibrium in Equation 1 would shift to the left.
HCL will protonate ammonia in a Bronstead acid-base rxn and reduce the amount of ammonia present. The disturbed equilibrium responds in a way to retore ammonia, which would decrease the concentration of complex ion formed.
Which of the following atoms will be expected to have the smallest second ionization energy?
A: Na
B: C
C: O
D:Ca
D: Ca
Metals have lower ionization energies than non-metals as long as the ionization event involves a valence electron. Since Na is an alkali metal, it has only one valence electron and has a large second ionization energy. Ca is an alkaline earth metal and has two valence electrons. It will therefore have the smallest second ionization energy of the four atoms listed.
What is the pH of a buffer solution that is .2 M in HCO3- and 2 M in H2CO3? (first pka of carbonic acid is 6.37)
A: 4.37
B: 5.37
C: 6.37
D: 7.37
B 5.37.
In order to calculate, need to use the HH equation: pH = pka + log (Base/acid). Plugging it in, pH = 6.37 + (log (.2/2) = 5.37.
An inflatable cuff was used to temporarily stop blood flow in an upper arm artery. While releasing the pressure to deflate the cuff, a stethoscope was used to listen the blood flow in the forearm. The blood pressure reading was 130/85. Given this information, which of the following statemetns is LEAST likely to be true?
A: 85 mmHg was the diastolic pressure.
B: Blood flow was heard when the pressure of the cuff was greater than 130 mmHg.
C: 130 mmHg was the systolic pressure.
D: Blood flow was heard when the pressure of the cuff was 90 mmHg.
B Blood flow was heard when P > 130mm Hg.
The cuff was inflated to temporarily stop blood flow in the artery. The systolic pressure is determined from the first sound of blood flow that can be heard once the pressure exerted by the inflatable cuff falls below pressure in artery. The blood pressure reading was 130/86, which indicates that blood flow started again when pressure was 130 mmHg. Blood flow was not heard when the pressure of the cuff was greater than 130 mmHg.
A is wrong b/c lower #s represents diastolic pressure.
C is incorrect b/c higher # is systolic pressure.
D is not the correct response b/c blood flow would be heard when pressure of cuff is 90 mmHg, as this pressure is higher than diastolic pressure.
Which single bond present in nitroglycerin (C3H5N3O9) is most likely the shortest?
A: C-H
B: C-O
C: C-C
D: O-N
A: C-H.
Hydrogen has amuch smaller atomic radius than any of the other elements listed, so we would assume its bond length is shorter s well. Also, we are given the bond energies. The higher the bond energy(energy to break the bond, the more stable it is), signifying it is shorter.
What is the average power consumed by a 64-year-old woman during the ascent of the 15-cm-high steps, if her mass is 54kg? The time involved was 27s.
A: 10 W
B: 20 W
C: 40 W
D: 90 W
D: 90 W.
Power consumed is equivalent to P = PE/time =mgh/t. From table 1, there are 30 steps and t= 27 s. Then P = (54kg x 10 m/s^2 X 30 steps x .15m/step)/(27 steps) = 90 W.
How much work did an 83yr-old female do while stretching the rubber band to the limit of her strength? She stretched it 20cm and the spring constant is 200 N/m
A: 4 J
B: 5 J
C: 6 J
D: 7 J
A: 4 J.
W = .5 * kx^2, where x=.20 m. W = .5 * 200 * .2m^2.
What kind of image is formed by the lenses of the glasses worn by a 68-yr-old male who sees an object 2m away? The lens have a negative focal length.
A: Real and enlarged
B: Real and reduced
C: Virtual and enlarged
D: Virtual and reduced
D: Virtual and Reduced.
The lens have a negative focal length, meaning they are diverging lens. Diverging lens form virtual and reduced images of objects situated at distances larger than focal length.
Inhibition of phosphofructokinase-1 by ATP is an example of:
- I: allosteric regulation*
- II: feedback inhibition*
- III: competive inhibition*
A: I only
B: III only
C: I and II only
D: II and III only
C: I and II only.
ATP, the end product of glycolysis, deregulates through feedback inhibition the activity of PFK-1 by binding to an allosteric site.
