# Tutor profile: Aida N.

## Questions

### Subject: Organic Chemistry

Why SN2 reactions are more favored at less substituted carbons?

SN2 reaction happens through back side attack of nucleophile while the leaving group is still attached to the molecule. This reaction happens only if empty orbital is accessible and goes faster as there are less groups around the leaving group. Therefore, the less substituted a carbon is, the more likely it goes through SN2 reaction. Think of it as finding your friend who is holding a drink in a bar and dancing with her. The less people around her, it is more likely that you find her so that she leaves her drink and dance with you.

### Subject: Biochemistry

Assuming rapid equilibrium, a reversible inhibitor has been added to an enzymatic reaction. A researcher claimed that the velocity equation of the enzyme is the following: $$V=\frac{v_{max} [S]}{K_{s}(1+\frac{[I]}{K_{I}})+[S]}$$ Using this equation, determine if this inhibitor is competitive, non-competitive, or uncompetitive.

The general equation of enzyme velocity is: $$V=\frac{v_{max} [S]}{K_{s}(Slope Factor)+[S](Velocity Factor)}$$ By analyzing the given equation, we see that the velocity factor is 1, in other words the inhibitor did not affect velocity factor of the enzyme. We know that the only type of reversible inhibitor that does not affect velocity factor is competitive inhibitor. To make sure, we can also check if the enzyme influences the slope factor. We know that competitive inhibitor causes slope factor to increase. The given equation follows this rule as well. As we increase [I] (inhibitor concentration), the slope factor ($$1+\frac{[I]}{K_{I}}$$) also increases. Therefor, we can confidently conclude that the inhibitor is a competitive inhibitor.

### Subject: Algebra

Find slope and y-intercept of the equation below: $$15y-30x=75$$

By looking at the equation we can tell that it is an equation of a straight line, and we know that the general equation of a straight line is $$y= mx+b$$, which $$m$$ is the slope of the line and $$b$$ is the y-intercept. So we rewrite the equation to better match the general equation of a straight line: $$15y=30x+75$$ Divide both sides by 15: $$(\frac{15}{15})y=(\frac{30}{15})x+(\frac{75}{15})$$ $$y=2x+5$$ Now that our equation looks more like the general equation of a straight line, we can find the slope and y-intercept: $$slope=2$$ $$y-intercept=5$$

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