Layan

“I am recruiting you to help me improve my English.”

I don’t know if what I care about is the grammar, I just wanna know if that sentence is correct. 

It will be followed by:

 “ From now on, I’ll text you only in English, and you can ( and should ) correct me whenever I make a mistake or you think my statement could be phrased better.” 

Does the follow up have mistakes ? 

"a more negative membrane potential indicates higher excitability because the more negative the potential, the more sodium channels are in the state of closed and capable of opening, while at a less negative membrane potential a higher percentage of channels are in the state of closed and incapable of opening than in a more negative membrane potential." 

This was written by one of the foreign high achievers in my class and I'm confused by how its true. 

If the RMP is more negative, wouldn't the neuron need a stronger stimulus for the threshold to be reached ? Wouldn't that make it less excitable than other neurons who are in an env with a less negative RMP ? 

Solutions A and B are separated by a membrane that is permeable to Ca2+ and impermeable to Cl−. Solution A contains 10 mM CaCl , and solution B

contains 1 mM CaCl2. 

Assuming that 2.3 RT/F = 60 mV, Ca2+ will be at electrochemical equilibrium when

(A) solution A is +60 mV

(B) solution A is +30 mV

(C) solution A is −60 mV

(D) solution A is −30 mV

(E) solution A is +120 mV

(F) solution A is −120 mV

(G) the Ca2+ concentrations of the two solutions are equal 

(H) the concentrations of the two solutions are equal

Now I know that solution A will have a negative potential difference and I would've assumed the answer was D but I'm confused about the 60mV they provided in the question. 

The equilibrium potential is the membrane potential at a specific concentration gradient when a specific ion is at equilibrium, correct ? An ion being at equilibrium just means that there is no net diffusion of the ion. 

If I use 60log(10/1) I'll get 60 mV 

What is this 60mV ? Is it the equilibrium potential of Ca2+ ions ? If yes why isn't the answer C ?

Is it okay to say 'and hence' ?

Disease is often considered to be a state of disrupted homeostasis. However, even in the presence of disease, homeostatic mechanisms continue to operate and main- tain vital functions through multiple compensations. In some cases, these compensations may themselves lead to major deviations of the body’s functions from the normal range, making it difficult to distinguish the primary cause

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of the disease from the compensatory responses.

What does this mean ?

When a solution of salt (sodium chloride) in water is treated with a silver nitrate solution, a white precipitate forms immediately. When tetrachloromethane is shaken with aqueous silver nitrate, no such precipitate is produced. Explain these facts in terms of the types of bonds present in the two chlorides.

For some reason I can't seem to differentiate between these 2 terms.

My book defines state function as

'a property of a system that depends only on its present state, which is determined by variables such as temperature and pressure and which is independent of any previous history of the system.'

What does that even mean ?

Ive seen sources try to explain it using GPE as an analogy but what does that do to me when it comes to determining whether Pressure or volume are state functions are or not ?

For context, I'm a first year uni student and this is from my general chemistry course.

thats it

"The strong, permanent magnetism seen in iron objects is called ferromagnetism and is due to the cooperative alignment of electron spins in many iron atoms. Paramagnetism is a much weaker effect. Nevertheless, paramagnetic substances can be attracted to a strong magnet. Liquid oxygen is composed of paramagnetic O2 molecules. When poured over a magnet, the liquid clings to the poles. "

I don't understand what they mean by 'cooperative alignment of electron spins ' ?

The question is :

During a normal translation cycle, Where would you expect to find t-RNA attached to a single amino acid ?

options :

1. E site

2.P site

3. A site

4. both E and P sites

5. both A and P sites

I say 3 , but I'm not sure since you can find a single amino acid in P site too

The buoyant force is a result of difference in pressures at the edges of the immersed object  right ? 

So if I immerse 2 objects with the same dimentions (so same volume) but very different densities 

Would I get the same bouyant force ? 

7. The weight of a car of mass 1.20 × 10^3 kg is supported equally by the four tires,

which are inflated to the same gauge pressure. What gauge pressure in the tires is

required so the area of contact of each tire with the road is 1.00 × 10^2 cm^2? (1 atm = 1.01

× 10^5 Pa.)

A) 11.6 × 10^5 Pa

B) 11.6 × 10^4 Pa

C) 2.94 × 10^5 Pa

D) 2.94 × 10^4 Pa

E) 2.94 × 10^3 Pa

The answer is C according to my professor

Here's my question, isn't that the absolute pressure ? 

Isn't the total pressure exerted by the tires = to gauge pressure+atm ?

By doing Force / 4A 

aren't I getting the total pressure ?