Compare the results observed for pairing (c ) to those observed for pairing (b). Based on these results, does the ob$^+$ gene product appear to promote or suppress appetite? Explain your answer.

a. Suppose that $F(x,y)=0$ defines $y$ implicitly as a function of $x$ and $F$ is differentiable. Write an expression for $\frac{dy}{dx}$. Illustrate with a tree diagram.

b. Suppose that $F(x,y,z)=0$ defines $z$ implicitly as a function of $x$ and $y$ and $F$ is differentiable. Write an expression for $\frac{\partial z}{\partial x}$. Illustrate with a tree diagram.

Given the following equations, evaluate dy/dx. Assume that each equation implicitly defines y as a differentiable function of x. $\sqrt { x ^ { 2 } + 2 x y + y ^ { 4 } }$=3

In which organ does almost all enzymatic digestion of food occur?

(A) stomach

(B) small intestine

(C) large intestine

(D) pancreas

$\text{\blue{WHAT IF?}}$ Thinking in broad terms, what similarities can you identify between digestion in an animal body and the breakdown of gasoline in an automobile engine? (You don’t have to know about auto mechanics.)

$\text{\blue{WHAT IF?}}$ Predict what would happen if you mixed gastric juice with crushed food in a test tube.

Formic acid, HCOOH, is a weak electrolyte. What solutes are present in an aqueous solution of this compound? Write the chemical equation for the ionization of HCOOH.

Write the formulas of the conjugate bases of the following acids:
$\mathrm{HCOOH}$ (formic acid)..

A sample of ${N}_2 {O}_4$ gas with a pressure of 1.00 atm is placed in a flask. When equilibrium is achieved, 20.0% of the ${N}_2 {O}_4$ has been converted to ${NO}_2$ gas.

(a) Calculate $K_{{p}}$.

(b) When the original pressure of ${N}_2 {O}_4$ is 0.10 atm, what is the percent dissociation of the gas? Is the result in agreement with Le Chatelier's principle?

An aqueous solution contains a mixture of $0.0500\ \mathrm { M }\ \mathrm { HCOOH } \left( K _ { \mathrm { a } } = 1.77 \times 10 ^ { - 4 } \right)$ and $0.150\ \mathrm { M }\ \mathrm { CH } _ { 3 } \mathrm { CH } _ { 2 } \mathrm { COOH } \left( K _ { \mathrm { a } } = 1.34 \times 10 ^ { - 5 } \right).$ Calculate the pH of this solution.

Solve the following.

A solution of formic acid $\left(\mathrm{HCOOH}, K_{\mathrm{a}}=1.8 \times 10^{-4}\right)$ has a pH of 2.70 . Calculate the initial concentration of formic acid in this solution.

A solution of formic acid $\left(\mathrm{HCOOH}, K_{\mathrm{a}}=1.8 \times 10^{-4}\right)$ has a pH of 2.70. Calculate the initial concentration of formic acid in this solution.

Hemoglobin carries O2 from the lungs to tissue cells, where the O2 is released. The protein is represented as Hb in its unoxygenated form and as Hb$\cdot$O2 in its oxygenated form. One reason CO is toxic is that it competes with O2 in binding to Hb: $\mathrm { Hb } \cdot \mathrm { O } _ { 2 } ( a q ) + \mathrm { CO } ( g ) \rightleftharpoons \mathrm { Hb } \cdot \mathrm { CO } ( a q ) + \mathrm { O } _ { 2 } ( g )$

If $\Delta G ^ { \circ } \approx ? 14 \mathrm { kJ }$ at $37 ^ { \circ } \mathrm { C }$ (body temperature), what is the ratio of [Hb$\cdot$CO] to [Hb $\cdot$O2] at $37 ^ { \circ } \mathrm { C }$ with [O2] = [CO]?

A Hemoglobin (Hb) can form a complex with both ${O}_2$ and CO. For the reaction

$${HbO}_2({aq})+{CO}({g}) \rightleftarrows {HbCO}({aq})+{O}_2({~g})$$

at body temperature, K is about 200. If the ratio [HbCO] / $[{HbO}_2]$ comes close to 1 , death is probable. What partial pressure of CO in the air is likely to be fatal? Suppose the partial pressure of ${O}_2$ is 0.20 atm.