Question

A. The food industry often uses catalytic hydrogenation to convert double bonds in the fatty acids of the oil triacylglycerols to -CH2-CH2-. How does this affect the physical properties of the oils. Which form provides greater energy upon combustion? Please explain your answers.

B.)How is it possible for some molecules to be at equilibrium across a biological membrane and yet not be at the same concentration on both sides?

Answer 1

(A)     Catalytic hydrogenation converts C=C to C-C

a) the first physical effect is the density of the substance, it will have more Hydrogen atoms per molecules, therefore, expect higher density (mass per unti volume). Also, interactions become more non-polar, since the molecules will become SATURATED.

b)

the double bond will always include more energy than the single bond. When burning (combustion) you will expect higher energy values or enthalpy hanges when "destroying" a double bond.

Actually

C = C H = 614

C—C H = 347

There is almost twice enery in the double bond than in the single bond

(B)

The most common for cells is the voltage of the membrane. So if you are talking about the equilibrium of sodium ions across a membrane. If the membrane voltage is 0 [and the membrane is permeable to sodium ions] then the equilibrium concentration of sodium ions will be equal on both sides of the membrane.

If there is a voltage applied across the membrane and one side is positive and the other is negatively charged, the the positively charged sodium ions will equilibriate with more positive sodium ions on the negative side of the membrane than on the positive side of the membrane, in order to negate the charge of the membrane.