Help with a few TBR problems

[nabilesmail]

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Hey guys can anyone explain the following.

TBR Bio Passage 9-1

problem 3


TBR Bio passage 10-10

problem 59


and TBR Physics, why does someone weigh more on the North pole vs the equator. I've never understood this.

Thanks!

 

[Ssina]

Hey guys can anyone explain the following.

TBR Bio Passage 9-1

problem 3

so the difference between the HbA and HbS is Glu vs. Val. you know that glutamic acid has an acidic side chain with carboxylate group (pKa 2-3) that at the buffered pH of 9 is deprotonated vs. valine that doesn't have the acidic side chain so doesn't have this extra negative charge... so essentially HbA is more negative and moves more toward the anode (positive electrode)

TBR Bio passage 10-10

problem 59

this is a game of probabilities... the probability of having this specific sequence of 4 bases for the RE to cut is 1/4 x 1/4 x 1/4 x 1/4 = 1/256

so every 256 base pares you will have this specific 4 sequences available for the RE to cut... so then 10000/256= 39 sites

and TBR Physics, why does someone weigh more on the North pole vs the equator. I've never understood this.

Thanks!

oooo I'm gonna let someone else tackle this one 😀

 

[MT Headed]

Your weight is the normal force the ground pushes up on you to keep you falling into the center of the earth. A person on the equator is in circular motion. They must have some force (gravity) pulling them into the center to keep them in circular motion. It turns out gravity is a little too strong, so the ground supplies some normal force to keep them from spiralling in. This normal force, less than the full force of gravity, is the weight.

As a silly example, if the earth spun at a million miles an hour, people on the equator would be flung into outer space and be weightless.

I hope this helps. I answered this question last year and some people still didn't get it.

 

[Ssina]

soo

at the poles: Fn=mg and since not really spinning, there is no Fc.
at the equator: Fc= mg - Fn, since Fc being the Fnet points inward and mg is bigger than Fn, otherwise we will fly outwards, as you mentioned.

so at poles: Fn=mg
at eq.: Fn=mg-Fc

so the slight difference comes out to be the Fc!
(sorry had to write it out to get it!)
Thanks