quick read through but these should be right
Woops. The OP actually has #2 wrong and I just glazed over it without paying close attention. He still did a good job with the rest.
#1) The Km is the substrate concentration at 1/2 Vmax. So basically it is just a constant to allow you, the researcher, to analyze the affinity of an enzyme or reaction. Since you need both the Y and X axis'es in order to have a slope you will need the substrate concentrations in order to determine Vmax.
Example: Hexokinase may have a Vmax of 200, whereas Fructokinase may have the same Vmax (for whatever reason, due to saturation, structural similarities, etc.) but they could very well (and I don't know if this is the case, just an example) have very different affinities and therefore a very different slope of the curve. Imagine if it was nearly a linear slope vs. another one which is a lot less rise/run --both can still have the same plateau. Hope that helps!
#2)
It's loss of atonia for sure. From Wiki: Rapid eye movement sleep behavior disorder (RBD) is a sleep disorder (more specifically a parasomnia) that involves abnormal behavior during the sleep phase with rapid eye movement (REM sleep). It was first described in 1986.
The major and arguably only abnormal feature of RBD is loss of muscle atonia (paralysis) during otherwise intact REM sleep.
The catch is always "most likely"
I put atonia and didn't miss it also if you want to be sure that was the correct answer.
Good luck!
Ok nkhan... i have oneeeee more q. last one i promise lol
An investigator is conducting an experiment on the physiologic resposne to agnonist mediated receptor activation. which of the following classes of drug receptors is most liekly to trigger the fastest measureable physiologic response
A. G protein coupled receptor ( i think this is the answers but need explanation)
B. Intracellular steroid receptor
C. Ligand coupled ion channel receptor
D. Receptor tyrosine kinases.
Also did you take NBME 7? Is it as hard as NBME 11/12? I thought NBME 11/12 were pretty difficult, but i guess thats mostly cuz i suck at timing and run out of time at the end of each block. Im taking it this saturday (only 4 days before my test and dont want to depress myself if i get lower than 228. So just want to know what to expect so i can be prepared. can i expect a higher score on 7?
Thanks nkhan! if u havent taken ur test yet, im sure ull get a 290
3. A 24yo woman is brought to ER by roommate cause of vomiting for 4 hrs. Also has 2day history of fatigue adn dizziness on standing. severe heartburn past 3 months. Antacids help provide relief. Pulse 110, RR 25, BP 95/70, Physical exam shows marked pallor, Hb 6 and Hct is 18. What is decreased in this patient?
a. alveolar Po2
b. arterial O2 carrying capacity
c. Arterial oxyhemoglobin saturation
d. arterial p50
e. arterial Po2
Marked pallor, with an Hb of 6 and Hct of 18 is a huge clue, if hemoglobin is lowered then by definition the arterial carrying capacity of O2 is lowered. Notice they did not say the carrying capacity of Hb (because that would be fixed for each molecule). The partial pressures will stay the same in this scenario which takes out the other answers, except for C, the explanation for C is that since the person is vomiting--loss of HCl--metabolic alkalosis--increase in pH --actually would cause less H+ and less salt bridges thus not favoring the T (taut) state and favoring the R (relaxed) state thus increasing the arterial Hb saturation (not decreasing).
