Why do macromolecules like proteins and polysaccharides have less effect on the osmolarity of a solution than an equal mass of their monomeric components?

Correct answer: Because their effect on osmolarity depends on the number of dissolved particles, not their mass.

Explanation

Osmolarity, a colligative property, depends on the number of solute particles per unit volume. Storing fuel as a large polymer like glycogen instead of many small monomers like glucose drastically reduces the number of solute particles, preventing dangerously high osmotic pressure within the cell.

Other questions

Question 1

What is the H—O—H bond angle in a water molecule, as stated in the text?

Question 2

What is the approximate bond dissociation energy for a hydrogen bond in liquid water?

Question 3

Which term describes compounds that are poorly soluble in water because they cannot form energetically favorable interactions with water molecules?

Question 4

What is the primary thermodynamic driving force for the aggregation of nonpolar compounds in aqueous solution?

Question 5

What is the value for the ion product of water, Kw, at 25 degrees Celsius?

Question 6

What is the pH of a solution with an H+ concentration of 1.3 x 10^-4 M?

Question 7

According to the titration curve for acetic acid (pKa = 4.76), in what state is the acid at the midpoint of the titration?

Question 8

Which of the following pairs represents a conjugate acid-base pair?

Question 9

What is the primary buffer system that acts in the cytoplasm of all cells?

Question 10

What is the pKa of the phosphate buffer system (H2PO4-/HPO4^2-), making it an effective buffer in biological fluids?

Question 11

In untreated diabetes mellitus, the accumulation of which two carboxylic acids can lead to a life-threatening condition called acidosis?

Question 12

The formation of ATP from ADP and inorganic phosphate is an example of what type of reaction where the elements of water are eliminated?

Question 13

What is the pH of a mixture of 0.042 M NaH2PO4 and 0.058 M Na2HPO4, given that the pKa is 6.86?

Question 14

What is the 'apparent pKa' or pKcombined for the bicarbonate buffer system in clinical medicine, which accounts for the reservoir of CO2(d)?

Question 15

What term describes the properties of water, such as vapor pressure and boiling point, that are altered by the presence of solutes?

Question 16

How do hydrogen bonds in ice differ from those in liquid water at room temperature?

Question 17

What is the van't Hoff factor (i) for a nonionizing solute like glucose?

Question 18

The buffering range of a weak acid and its conjugate base generally extends about how many pH units on either side of its pKa?

Question 19

What is the term for a solution that has a higher osmolarity than that of a cell's cytosol, causing the cell to shrink?

Question 20

Hydrogen bonds are strongest and most stable when the hydrogen atom and the two atoms that share it are oriented in what way?

Question 21

What is the concentration of H+ in a solution of 0.1 M NaOH?

Question 22

A reaction that involves the cleavage of a bond accompanied by the addition of the elements of water is known as what?

Question 24

What is the dielectric constant of water at 25 degrees Celsius, which allows it to effectively screen electrostatic interactions between dissolved ions?

Question 25

In a solution of a weak acid, if the pH is two units below its pKa, what is the approximate ratio of the conjugate base [A-] to the weak acid [HA]?