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Altius FL #3
#1 Posted : Sunday, July 04, 2021 7:55:11 PM
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I had some questions from Altius FL #3 C/P Section:

Q8: How is DNA/RNA a source for dietary phosphate? Why is option D not a good answer?

Q12: For the most effective quantitative tool, why do you need a high variability? My thought process was that it would be answer choice B, because it shows the greatest difference between the control line and test line and therefore it would be able to differentiate it easily.

Q29: Why would option C not work?

Q36: Option D is also a negative control, why is option B better?

Q41: If Kw increases, therefore the dissociation of H20 increases, and therefore the concentration of H+ and OH- should also increase in equal amounts. Shouldn’t the solution stay at pH of 7?

Q42: What are unbalanced forces and why can Newton's law not be applied here?

Q50: How do you know PLP is bonded to glycogen and not glucose? It looks like it is bonded to a glucose monomer to me. Also, It seems that it is donating its electrons to form a bond so why is option C incorrect?

Q53: If you add water, wouldn't the molecular weight increase?

Other Questions:
Is all binding between an antigen/antibody, binding molecules, or between two things is concerned with intermolecular forces? If so, why is a peptide bond covalent and not a hydrogen bond (intermolecular force)?

Does resonance prevent free rotation for all molecules?
#2 Posted : Wednesday, July 07, 2021 5:14:06 PM
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Hi Moiz,

I've got answers to most of your questions. Hopefully another instructor can chime in with the rest. 😊

Q8: This is a question of elimination.

We want phosphorus. Protein is a great source of nitrogen. No amino acids contain phosphorus.

Hydroxyapatite is used in some toothpastes. Don't eat toothpaste.

Aminobisphosphonate is mentioned as being a bad thing in the passage. Don't eat that.

Phosphoric acid does contain phosphorus. Soft drinks have this as an additive to give a yummy sharp taste. But, there isn't much phosphorus in there... For example, one diet pepsi has 30 mg, or 2% of your RDA of phosphorus.

So, by process of elimination, it's gotta be C. Also, do RNA and DNA have phosphorus in them? Oh yeah. Phosphate groups!

Q12: In the concentration from 0.1 to 1 ng/mL, we have an almost linear graph (very easy to get a mathematical equation to represent that section) AND a very large change in intensity. These are both great things!!

From 0.1 to 100 ng/mL, we barely gain any change in intensity compared to the previous case, and we also have a much more complicated mathematical model (logarithmic? two straight lines combined?).

So, answer D is the best.

Q29: C isn't an amino acid. The question states that you need to start with an amino acid.

Q36: D is already included in the experiment as a negative control (look at the last line in the chart, with Cut6 -- it retains 100% residual activity).

So, B is the best answer.

Q41: Let's do the math.

At 37°C (physiological conditions), Kw = 10^-14, [H+] = 10^-7, so pH = 7.

Let's crank things up: Kw = 100 x 10^-14 = 10^-12, [H+] = 10^-6, so pH = 6.

The pH has decreased by 1 unit.

Q42: An unbalanced force is when Fnet is not equal to zero.

So, if Fnet != 0, then Fnet = ma, which is Newton's second law.

When Fnet = 0, we have Newton's first law (inertia!).

Q50: You're right, it's only a glucose monomer. This reaction takes glycogen and breaks it up into glucose subunits. That's the purpose of GP.

This question is very sneaky. The big thing that I looked for was "is there any time that a hydrogen got moved?"


From the first step to the second step, a hydrogen was "kicked out" from the phosphate group.

It is very subtle, but that's the answer to the question.

Q53: I'll use an analogy to explain this:

Consider 100 g of pure gold. You go get it appraised. Ooooh, you're gonna be rich!

Consider 95 g of gold tainted with 5 g of brass. You THINK it's still 100% gold. You go get it appraised. HEY. Why isn't it worth as much anymore?

Same idea as the question. 100% pure molecule has a HIGHER molecular weight than wet molecule. The water is "tainting" the molecule (because it is lighter) and bringing the average molecular weight DOWN.
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