Chapter 3: The Chemical Basis of Life

Question 1

What is an element?

Answer 1

Pure substance made up of only one kind of element.

Question 2

What is a compound?

Answer 2

A substance made up of more than one kind of pure substance.

Question 3

O2 is an example of a compound T | F

Answer 3

False

Question 4

CO2 is an example of a compound T | F

Answer 4

True

Question 5

26 Elements in the human body T | F

Answer 5

True

Question 6

N, O, C, & H make up 96% of the human body T | F

Answer 6

True

Question 7

Atoms

Answer 7

Smallest part of a chemical element that retains the properties of that element.

Question 8

Molecules are a combination of ______:

Answer 8

Atoms

Question 9

Protons + #Neutrons=

Answer 9

Atomic Mass

Question 10

Atomic Mass is the # of _______:

Answer 10

Protons in the nucleus.

Question 11

What are the 2 types of chemical bonds?

Answer 11

Ionic & Covalent

Question 12

Ionic Bonds

Answer 12

Donating/taking electrons from another atom that only has 1 or 2 in its outermost layer. Formed when + and - ions attract b/c of attraction.

Question 13

Ion

Answer 13

Atom or group of atoms with an electrical charge (+ or -).

Question 14

+ ion has _____ electrons.

Answer 14

Lost

Question 15

• ion has _____ electrons.

Answer 15

Gained

Question 16

Dissociation

Answer 16

When molecules dissolve in water b/c water molecules wedge b/w the ions and force them apart.

Question 17

Covalent Bonds

Answer 17

Fills their energy levels by sharing. Atoms must stay close. C, O, H, and N almost always form CB.

Question 18

Hydrogen Bonds

Answer 18

Results from an unequal charge distribution on molecules.

Question 19

Hydrogen bonds are stronger than covalent or ionic bonds T | F

Answer 19

False

Question 20

What are the 3 types of chemical reactions?

Answer 20

Synthesis, decomposition, and exchange.

Question 21

Synthesis

Answer 21

A+B–>AB

Question 22

Decomposition

Answer 22

AB–>A+B

Question 23

Exchange

Answer 23

AB+CD–>AD+CB

Question 24

Catabolism

Answer 24

Breaks down

Question 25

Anabolism

Answer 25

Simple molecules join together to form complex compounds.

Question 26

Organic Molecule

Answer 26

Contain at least 1 carbon atom and at least one C-C or C-H bond.

Question 27

Inorganic Molecule

Answer 27

Have few C atoms and don’t haveH2O

Question 28

Water is an organic compound T | F

Answer 28

False

Question 29

What are the 4 properties of H2O?

Answer 29

Polarity, high specific heat, solvent, high heat of vaporization

Question 30

Polarity

Answer 30

One of the properties of H2O. Allows H2O to act as a solvent in the body. Ionizes substances in the solution.

Question 31

Solvent

Answer 31

One of the properties of H2O. Transportation of essential molecules throughout the body.

Question 32

High Specific Heat

Answer 32

One of the properties of H2O. Water can gain and lose and gain large amounts of heat w/ little change to its own temperature.

Question 33

________________ enables the body to maintain a constant temperature.

Answer 33

High specific heat

Question 34

High Heat of Vaporization

Answer 34

Water requires the absorption of significant amounts of heat to change it from a liquid to gas.

Question 35

___________ allows the body to dissipate heat.

Answer 35

High heat of vaporization

Question 36

Hydrolysis

Answer 36

Water is added to the subunits of a large molecule to break it apart.

Question 37

Dehydration Synthesis

Answer 37

Water is removed from small molecules so they can be strung together to form a larger molecule.

Question 38

Electrolyte

Answer 38

A molecule that dissociates in H2O to form individual ions. An ionic compound, usually electrically charged.

Question 39

Acid

Answer 39

In favour of H+

Question 40

Base

Answer 40

Away from H+

Question 41

In pure water, the OH- and H+ balance is equal T | F

Answer 41

True

Question 42

pH

Answer 42

Used to express the H+ concentration in a solution.

Question 43

7> is an acid, 7< is a base. T | F

Answer 43

True

Question 44

What is a buffer?

Answer 44

Binds with the acid and base to reduce their effect.

Question 45

Strong acids and bases form together to form water and OH- T | F

Answer 45

False, they produce H2O & salt

Question 46

Covalent bonds usually do not dissociate in water T | F

Answer 46

True