Water, pH, Buffers

Question 1

water is an ____ molecule

Answer 1

active

Question 2

What are the two major roles of water in biological systems?

Answer 2

maintain 3D structure, actively participates in reactions

Question 3

When DNA and RNA are covalently linked, a water molecule is ____

Answer 3

released

Question 4

Protein digestion does what with water?

Answer 4

uses up

Question 5

What happens when DNA is dried out?

Answer 5

the structure is changed and it does not function normally

Question 6

What has a relatively ___ BP

Answer 6

high

Question 7

When water is heated, H bonds are broken more ____

Answer 7

rapidly

Question 8

Electrons are drawn to which element in water?

Answer 8

O

Question 9

Electrons are drawn away from which element in water?

Answer 9

H

Question 10

Electronegative O and the H atoms form what type of moment?

Answer 10

dipole

Question 11

Is water polar or non-polar?

Answer 11

polar

Question 12

H-bonds in liquid water are ____ lived

Answer 12

short

Question 13

What besides charge causes the dipole moment of water?

Answer 13

bond angle is not 180 (is 104.3)

Question 14

The H of one water molecule bonds to the ___ of the other water molecule

Answer 14

O

Question 15

O can make ____ H bonds at a time

Answer 15

2

Question 16

H can make ____ H bonds at a time

Answer 16

1

Question 17

H2O can make ____ H bonds at a time

Answer 17

4

Question 18

What state of water has a fixed, 3D network with an open lattice structure?

Answer 18

solid

Question 19

Ice has a ____ density

Answer 19

low

Question 20

Why does ice float on water?

Answer 20

it is less dense

Question 21

Water is a _____ solvent

Answer 21

good

Question 22

What does the ability of water to be a good solvent depend on?

Answer 22

the chemical nature of what is being mixed

Question 23

What type of substances does water form hydrogen shells around?

Answer 23

ionic

Question 24

Water forms a _____ when making a hydrogen shell

Answer 24

fixed coating

Question 25

What is a clathrate structure?

Answer 25

cage like

Question 26

What type of molecules does water make a clathrate structure around?

Answer 26

hydrophobic

Question 27

Do hydrophobic molecules directly interact with water?

Answer 27

no

Question 28

Water interacts with what part of the hydrophobic molecule?

Answer 28

surface

Question 29

What is another term for nonpolar solute molecules?

Answer 29

hydrophobic

Question 30

Water forms micelles around what type of molecule?

Answer 30

amphiphilic

Question 31

What is an amphiphilic molecule?

Answer 31

2 chemical natures in 1 molecule

Question 32

Fatty acids have a ____ head

Answer 32

polar

Question 33

Fatty acids have a ____ tail

Answer 33

non-polar

Question 34

What is the nonpolar tail of fatty acids made of?

Answer 34

C-H bonds

Question 35

Why are C-H bond chains hydrophobic?

Answer 35

They have no interactive chemical group present

Question 36

What shaped is a micelle?

Answer 36

sphere

Question 37

What type of molecule forms a lipid bilayer?

Answer 37

a more complex amphiphilic molecule

Question 38

A lipid bilayer is a ___D structure

Answer 38

2

Question 39

Lipid bilayers are the same structure as biological _____

Answer 39

membranes

Question 40

The lipid bilayer acts as a ____ for small molecules

Answer 40

barrier

Question 41

The charged groups of an amphiphilic molecule ____ with water

Answer 41

interact

Question 42

Colligative properties depend on what?

Answer 42

number of solute particles per unit volume

Question 43

Colligative properties do not depend on what?

Answer 43

the chemical nature of the solute

Question 44

The more you mix in the ____ the freezing point

Answer 44

lower

Question 45

Water molecules move from the region of ____ H2O concentration to the region of _____ H2O concentration

Answer 45

higher, lower

Question 46

Osmotic pressure is important in what type of cells?

Answer 46

red blood cells

Question 47

What is pH a measure of?

Answer 47

hydrogen ion concentration

Question 48

A large H+ concentration is a ____ substance

Answer 48

acidic

Question 49

A small H+ concentration is a ____ substance

Answer 49

basic/ alkaline

Question 50

H+ concentration and OH- concentration are ______ related

Answer 50

inversely

Question 51

H+ and OH- concentrations are even when a substance is _____

Answer 51

neutral

Question 52

What is the physiological pH?

Answer 52

7.4

Question 53

What does a buffer do?

Answer 53

maintain pH value

Question 54

What must a pH be maintained?

Answer 54

to preserve structure and function

Question 55

Phosphate buffer system buffers _____

Answer 55

the intracellular fluid of cells

Question 56

Carbonate buffer system buffers _____

Answer 56

blood plasma

Question 57

In the phosphate buffer system, OH- is neutralized by _______ to make water and HPO42-

Answer 57

H2PO4-

Question 58

In the phosphate buffer system, H+ is neutralized by ______ to make H2PO4-

Answer 58

HPO42-

Question 59

In the carbonate buffer system, H+ is neutralized by ____ to make H2CO3

Answer 59

HCO3-

Question 60

In the carbonate buffer system, OH- is neutralized by ______ to make HCO3- and water

Answer 60

H2CO3

Question 61

Ions in solution interact with water to form____

Answer 61

hydrogen shells

Question 62

The structure of water is hexagonal because there are 6 water molecules in any H-bonded ___ ____

Answer 62

closed path

Question 63

Each integer on the pH scale increases or decreases H+ concentration by _____

Answer 63

tenfold