Chapter 2: Water

Question 1

______ is a critical determinant of the structure and function or proteins, nucleic acids, and membranes

Answer 1

Water

Question 2

Dipole moment

Answer 2

Allows water to serve as a hydrogen bond donor and acceptor

Question 3

Water in a solid state

Answer 3

Ice

Question 4

Ice has a lower or higher density than water

Answer 4

Lower; Hexagonal ice contains more hydrogen bonds making it less dense

Question 5

Water is a good solvent for ….

Answer 5

charged and polar substances which form H bonds

Question 6

Water is a bad solvent for …

Answer 6

nonpolar substances because they cant form H bonds and greatly disrupt the water lattice

Question 7

An environment where water moves into cells and distend the plasma membrane and cause lysis

Answer 7

Hypotonic environment

Question 8

Strong covalent bonds

Answer 8

Sharing of electrons

Question 9

Ionic interactions

Answer 9

Electrostatic interactions between permanently charged species, or between the ion and a permanent dipole

Question 10

Van der waals Interaction

Answer 10

Weak interactions between all atoms, regardless of polarity, attractive (dispersion) and repulsive

Question 11

Hydrophobic effect

Answer 11

The ordering of water molecules around nonpolar substances

Question 12

For every enzyme, there is an _______

Answer 12

Optimal pH

Question 13

The effects of changing the pH

Answer 13

• Affect H bond donors/acceptors
• Change solubility of polar molecules
• Change the active site
• Destabilize the structure

Question 14

Buffer system in vivo are mainly based on

Answer 14

Phosphate, bicarbonate, histidine

Question 15

Buffer system in nitro are based on …

Answer 15

Sulfonic acids, Tris, Phosphate

Question 16

Phosphate

Answer 16

Concentration

Question 17

Bicarbonate

Answer 17

Important for blood plasma

Question 18

Histidine

Answer 18

Efficient buffer at neutral pH

Question 19

Acidosis

Answer 19

pH below 7.4, a pH below 7 is deadly

Question 20

Alkalosis

Answer 20

pH above 7.4

Question 21

The only amino acid that can serve as a buffer in the body

Answer 21

Histidine

Question 22

True or False:

Ice is less dense than water

Answer 22

True

Question 23

Bent geometry of water because H does not cancel out, which would making a dipole moment

Answer 23

Water is a polar molecule

Question 24

The arrangement of ice

Answer 24

Hexagonal ice forms a regular lattice

Question 25

Water is a good or bad solvent for charged and polar substances, which forms H bonds?

Answer 25

good solvent

Question 26

Water is a poor solvent for _______ molecules?

Answer 26

nonpolar

Because they cant form hydrogen bonds

Question 27

Acidosis

Answer 27

pH below 7.4

Question 28

Alkalosis

Answer 28

pH above. 7.4

Question 29

Enzyme in the stomach has a pH range of

Answer 29

1.5 -3.5