Water and PH

Question 1

What enable water to dissolve large quantities of charged compounds such as salts.?

Answer 1

strong dipole and high dielectric constant

Question 2

What physical properties is influnced by the hydrogen bond?

Answer 2

High viscosity, BP, Surface tension increase

Question 3

This can serve both as hydrogen acceptors and as donors of unshielded hydrogen atoms for formation of hydrogen bonds

Answer 3

Alcohols, carboxylic acids, and amines

Question 4

this bond is the strongest force that holds molecules together

Answer 4

Covalent

Question 5

what is phospholipid bilayer called?

Answer 5

phosphatidylserine or phosphatidylethanolamine

Question 6

Hydrophobic Interactions

Answer 6

Hydrophobic interaction refers to the tendency of nonpolar compounds to self-associate in an aqueous environment.

Question 7

this minimizes the disruption of energetically favorable interactions between the surrounding water molecules in hydrophobic interaction.

Answer 7

Self-association

Question 8

Electrostatic Interactions

Answer 8

Interactions between charged groups help shape biomolecular structure.

Question 9

Electrostatic interactions between oppositely charged groups within or between biomolecules are termed

Answer 9

salt bridges

Question 10

van der Waals Forces

Answer 10

van der Waals forces arise from attractions between transient dipoles generated by the rapid movement of electrons of all neutral atoms.

Question 11

van der Waals interactions in dna is between

Answer 11

the stacked purine and pyrimidine bases.

Question 12

Nucleophilic attack by water typically results in the cleavage of the amide, glycoside, or ester bonds that hold biopolymers together. This process is termed .

Answer 12

hydrolysis

Question 13

The ability of water to……, while slight, is of central importance for life

Answer 13

water to ionize

Question 14

water can act both as an acid and as a base

Question 15

water Protons exist in solution not only as H3O+, but also as multimers such as H5O2+ and H7O3+

Question 16

The actual probability of a hydrogen atom in pure water existing as a hydrogen ion is approximately 1.8 × 10−9.

Answer 16

1.8 × 10−9.

Question 17

The term pH was introduced in 1909 by

Answer 17

Sörensen

Question 18

Compounds that contain ………. can serve as hydrogen bond donors and/or acceptors.

Answer 18

O or N

Question 19

……….. dictate that macromolecules expose polar regions to an aqueous interface and bury nonpolar regions.

Answer 19

Entropic forces

Question 20

this forces participate in maintaining molecular structure.

Answer 20

Salt bridges, hydrophobic interactions, and van der Waals

Question 21

The strength of weak acids is expressed by pKa, the negative log of the acid dissociation constant. Strong acids have low pKa values and weak acids have high pKa values.

Question 22

Buffers resist a change in pH when protons are produced or consumed. Maximum buffering capacity occurs ±1 pH unit on either side of pKa. Physiologic buffers include bicarbonate, orthophosphate, and proteins.