chapters 3-4

Question 1

why is water molecule a polar molecule

Answer 1

the opposite ends have opposite charges

Question 2

define polarity

Answer 2

allows water molecules to form hydrogen bonds with each other

Question 3

what are the four common properties of water

Answer 3

cohesive behavior, ability to moderate temperature, expansion upon freezing, versatility as a solvent

Question 4

define cohesion

Answer 4

when hydrogen bonds hold water molecules together, helps transport water against gravity in plants

Question 5

define adhesion

Answer 5

an attraction between different substances, for example between water and plant cell walls

Question 6

define surface tension

Answer 6

a measure of how hard it is to break the surface of a liquid, related to cohesion

Question 7

why does water have an unusually high surface tensions

Answer 7

due to hydrogen bonding between the molecules at the air water interface and to the water below

Question 8

temperature measures ____

Answer 8

the intensity of heat due to the average kinetic energy of molecules regardless of volume

Question 9

define heat

Answer 9

a measure of the total amount of kinetic energy due to molecular motion

Question 10

define thermal energy

Answer 10

reflects total kinetic energy and depends on matters volume

Question 11

define specific heat of a substance

Answer 11

the amount of heat that must be absorbed or lost for 1 g of that substance to change its temperature by 1 degree celsius

Question 12

what is absorbed and released when hydrogen bonds form and break

Answer 12

heat

Question 13

define solution

Answer 13

a liquid that is a homogeneous mixture of substances

Question 14

define solvent

Answer 14

the dissolving agent of a solution

Question 15

define solute

Answer 15

the substance that is dissolved

Question 16

define aqueous solution

Answer 16

a solution in which water is the solvent

Question 17

define hydrophilic substance

Answer 17

one that has an affinity for water

Question 18

define hydrophobic substance

Answer 18

one that does not have an affinity for water

Question 19

define acid

Answer 19

any substance that increases the H+ concentration of a solution, have pH values less than 7

Question 20

define base

Answer 20

any substance that reduces the H+ concentration of a solution, pH values of greater than 7

Question 21

what is the pH of blood

Answer 21

7.4

Question 22

define buffers

Answer 22

substances that minimize changes in concentrations of H+ and OH– in a solution, consist of an acid-base pair that reversibly combines with H+

Question 23

blood has natural buffers called

Answer 23

bicarbonates

Question 24

define organic chemistry

Answer 24

the study of compounds that contain carbon

Question 25

define hydrocarbons

Answer 25

organic molecules consisting of only carbon and hydrogen, form nonpolar molecules, example is methane and ethane

Question 26

define isomers

Answer 26

compounds with the same molecular formula but different structures and properties

Question 27

define structural isomers

Answer 27

different covalent arrangements of their atoms

Question 28

define enantiomers

Answer 28

isomers that are mirror images of each other

Question 28

define cis-trans isomers

Answer 28

same covalent bonds but differ in spatial arrangements

Question 29

define functional groups

Answer 29

the components of organic molecules that are most commonly involved in chemical reactions giving its unique properties

Question 30

a ___ is dissolved in a ___ creating a ____

Answer 30

solute, solvent, and solution

Question 31

name the chemical group:
can form covalent cross-links that stabilize protein structure

Answer 31

sulfhydryl group

Question 32

name the chemical group:
can affect gene expression

Answer 32

methyl group

Question 33

name the chemical group:
key component of ATP

Answer 33

phosphate group

Question 34

name the chemical group:
is always polar

Answer 34

hydroxyl group

Question 35

name the chemical groups:
two groups of sugars

Answer 35

carbonyl and hydroxyl groups

Question 36

name the chemical group:
has acidic properties

Answer 36

carboxyl group

Question 37

name the chemical group:
acts as a base

Answer 37

amino group