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Question 1

What is the mass number of an element?

Answer 1

The quantity of its protons, called its atomic number.

Question 2

What contributes nearly all of an atom’s mass?

Answer 2

Protons and neutrons.

Question 3

What is the outermost electron shell of an atom called?

Answer 3

Valence shell.

Question 4

Why are helium and larger atoms with eight electrons in their valence shell unlikely to participate in chemical reactions?

Answer 4

Because they are stable.

Question 5

What do all other atoms tend to do with their electrons?

Answer 5

Accept, donate, or share electrons.

Question 6

What is the goal of this electron behavior?

Answer 6

To bring the electrons in their valence shell to eight (or two in the case of hydrogen).

Question 7

What are ions?

Answer 7

Charged atoms formed by donating or accepting electrons.

Question 8

What is an ionic bond?

Answer 8

Attraction between cations and anions.

Question 9

What are covalent bonds?

Answer 9

Atoms sharing electrons.

Question 10

What are nonpolar covalent bonds?

Answer 10

Electrically balanced bonds with a linear shape.

Question 11

What are polar covalent bonds?

Answer 11

Bonds with regions of weak positive and negative charge and a triangular shape.

Question 12

How are water molecules formed?

Answer 12

An oxygen atom and two hydrogen atoms form polar covalent bonds.

Question 13

What are hydrogen bonds?

Answer 13

Bonds linking hydrogen atoms to anions or electronegative regions of other polar molecules.

Question 14

What do hydrogen bonds do in water?

Answer 14

Link water molecules together.

Question 15

What are the properties of water?

Answer 15

Properties important to living things.

Question 16

What is the initial investment of energy in chemical reactions called?

Answer 16

Activation energy.

Question 17

What is kinetic energy?

Answer 17

Energy of matter in motion.

Question 18

What fuels the collisions necessary for chemical bond formation?

Answer 18

Kinetic energy.

Question 19

What is potential energy?

Answer 19

Energy stored in molecules.

Question 20

What are the four forms of energy essential to human functioning?

Answer 20

Chemical, mechanical, radiant, and electrical energy.

Question 21

What is chemical energy?

Answer 21

Energy stored and released in chemical bonds.

Question 22

What is mechanical energy?

Answer 22

Energy that directly powers physical activity.

Question 23

What is radiant energy?

Answer 23

Energy emitted as waves, such as sunlight.

Question 24

What is electrical energy?

Answer 24

Energy of moving electrons.

Question 25

What are reactants and products in a chemical reaction?

Answer 25

Reactants are the starting substances and products are the end substances.

Question 26

What happens in a synthesis reaction?

Answer 26

Reactants are bonded together to form a product.

Question 27

What happens in a decomposition reaction?

Answer 27

Bonds within a reactant are broken, releasing energy.

Question 28

What happens in an exchange reaction?

Answer 28

Bonds are both broken and formed, and energy is exchanged.

Question 29

What properties of reactants influence the rate of a chemical reaction?

Answer 29

Temperature, concentration, pressure, and the presence of a catalyst.

Question 30

What is an enzyme?

Answer 30

A catalytic protein that speeds up chemical reactions in the body.

Question 31

What are some inorganic compounds essential to human functioning?

Answer 31

Water, salts, acids, and bases.

Question 32

What are the functions of water in the body?

Answer 32

Lubricant, cushion, heat sink, component of mixtures, reactant in hydrolysis reactions.

Question 33

What happens when salts are dissolved in water?

Answer 33

They dissociate into ions other than H+ or OH-.

Question 34

What do acids release in solution?

Answer 34

H+ ions, making the solution more acidic.

Question 35

What do bases do in solution?

Answer 35

Accept H+ ions, making the solution more alkaline.

Question 36

What is the pH of a neutral solution?

Answer 36

pH 7.

Question 37

What is the pH range of blood in a healthy adult?

Answer 37

7.35 to 7.45.

Question 38

What are buffers?

Answer 38

Chemicals that help maintain the pH of body fluids.

Question 39

What happens when the pH of blood fluctuates outside the normal range?

Answer 39

Weak acids and weak bases are released to restore pH.

Question 40

What does a change in a single digit on the pH scale represent?

Answer 40

A ten-fold increase or decrease in H+ concentration.

Question 41

What is the role of buffers in homeostatic control?

Answer 41

To keep blood pH within a healthy range.

Question 42

What are organic compounds?

Answer 42

Compounds containing carbon and hydrogen.

Question 43

What are the four essential organic compounds in human functioning?

Answer 43

Carbohydrates, lipids, proteins, and nucleotides.

Question 44

Why are organic compounds called organic?

Answer 44

Because they contain carbon and hydrogen.

Question 45

What atoms do carbon atoms in organic compounds readily share electrons with?

Answer 45

Hydrogen, oxygen, and sometimes nitrogen.

Question 46

What are functional groups?

Answer 46

Groups of atoms that can bond with carbon atoms.

Question 47

What are some examples of functional groups?

Answer 47

Carboxyls, hydroxyls, aminos, and phosphates.

Question 48

What are monomers?

Answer 48

Single units of organic compounds.

Question 49

How do monomers bond to form polymers?

Answer 49

Through dehydration synthesis.

Question 50

How can polymers be broken?

Answer 50

Through hydrolysis.

Question 51

What is the function of carbohydrates?

Answer 51

To provide essential body fuel.

Question 52

What are the structural forms of carbohydrates?

Answer 52

Monosaccharides, disaccharides, and polysaccharides.

Question 53

Give examples of monosaccharides.

Answer 53

Glucose.

Question 54

Give examples of disaccharides.

Answer 54

Lactose.

Question 55

Give examples of polysaccharides.

Answer 55

Starches, glycogen, and fiber.

Question 56

What can all body cells use glucose for?

Answer 56

Fuel

Question 57

What happens to glucose to be converted into ATP?

Answer 57

It undergoes an oxidation-reduction reaction.

Question 58

What are lipids?

Answer 58

Hydrophobic compounds that provide body fuel and are important components of many biological compounds.

Question 59

What is the most abundant lipid in the body?

Answer 59

Triglycerides.

Question 60

What are triglycerides composed of?

Answer 60

A glycerol backbone attached to three fatty acid chains.

Question 61

What are phospholipids?

Answer 61

Compounds composed of a diglyceride with a phosphate group attached at the molecule's head.

Question 62

What is the result of the structure of phospholipids?

Answer 62

A molecule with polar and nonpolar regions.

Question 63

What are steroids?

Answer 63

Lipids formed of four hydrocarbon rings.

Question 64

What is the most important steroid?

Answer 64

Cholesterol.

Question 65

What are prostaglandins?

Answer 65

Signaling molecules derived from unsaturated fatty acids.

Question 66

What are proteins?

Answer 66

Critical components of all body tissues.

Question 67

What are the monomers of proteins called?

Answer 67

Amino acids.

Question 68

What is the bond that joins amino acids in proteins?

Answer 68

Peptide bonds.

Question 69

Why is protein shape critical to its function?

Answer 69

Because it determines its function.

Question 70

What is an example of a globular protein?

Answer 70

Enzymes.

Question 71

What is the function of enzymes?

Answer 71

To catalyze chemical reactions.

Question 72

What are nucleotides?

Answer 72

Compounds with phosphate groups, pentose sugar, and nitrogen-containing base.

Question 73

What are DNA and RNA?

Answer 73

Nucleic acids involved in protein synthesis.

Question 74

What is ATP?

Answer 74

Body's fundamental molecule for energy transfer.

Question 75

What happens when phosphates are removed or added?

Answer 75

Energy is released or invested.