Study Guide B pt 2

Question 1

What is a polar molecule?

Answer 1

a molecule with a slightly positively charged region and a slightly negatively charged region

Question 2

Explain why water is a polar molecule.

Answer 2

the oxygen nucleus pulls the electrons in the molecule more strongly than the hydrogen atoms. The hydrogen atoms have a slight positive charge and the oxygen atom has a slight negative charge.

Question 3

What is a hydrogen bond?

Answer 3

an attraction between a slightly positive hydrogen and a slightly negative atom

Question 4

Describe where a hydrogen bond can form among water molecules.

Answer 4

between the slightly positive hydrogen atom of one water molecule and the slightly negative oxygen atom of another water molecule.

Question 5

describe high specific heat

Answer 5

a large amount of energy is needed to produce an increase in water temperature; water resists changes in temperature

Question 6

describe cohesion

Answer 6

water molecules “stick” to each other

Question 7

describe adhesion

Answer 7

water molecules “stick” to other substances

Question 8

What is the difference between a solvent and a solute?

Answer 8

a solvent is present in greater concentration and dissolves the solute

Question 9

What types of substances dissolve easily in water?

Answer 9

polar molecules and ions

Question 10

What types of substances do not dissolve easily in water?

Answer 10

Nonpolar molecules (such as fats & oils)

Question 11

Effect an acid has on H+ concentration in a solution

Answer 11

increases H+ concentration

Question 12

Effect a base has on H+ concentration in a solution

Answer 12

decreases H+ concentration

Question 13

Effect an acid has on pH

Answer 13

lower pH

Question 14

Effect a base has on pH

Answer 14

raise pH

Question 15

define solution

Answer 15

a homogeneous mixture of substanes

Question 16

define solvent

Answer 16

substance present in greater amount in which other substances dissolve

Question 17

define solute

Answer 17

substance that dissolves in a solvent

Question 18

Why is carbon often called the building block of life?

Answer 18

carbon atoms are the basis of the molecules that make up most living things

Question 19

What ability allows carbon atoms to form a large number of molecules?

Answer 19

carbon atoms can form covalent bonds with up to four other atoms, including other carbon atoms

Question 20

function of carbohydrates

Answer 20

broken down as a source of chemical energy (short term energy); part of cell structure

Question 21

function of lipids

Answer 21

broken down as a source of chemical energy (long term energy); part of cell structure

Question 22

function of proteins

Answer 22

many functions, including movement, transport, chemical catalysts

Question 23

function of nucleic acids

Answer 23

store genetic information, build proteins

Question 24

examples of carbohydrates

Answer 24

sugars, starches, cellulose

Question 25

examples of lipids

Answer 25

fats, oils, phospholipids

Question 26

examples of proteins

Answer 26

enzymes, hemoglobin

Question 27

examples of nucleic acids

Answer 27

DNA, RNA

Question 28

What determines a protein's structure and function?

Answer 28

The order of amino acids and interactions between amino acids (hydrogen bonds + sulfer-sulfer bonds)

Question 29

What are nucleic acids made of?

Answer 29

Nucleotides, which are composed of a sugar, a phosphate group, and a nitrogen-containing base

Question 30

The prefix mono- means "one," and the prefix poly- means "many." How are these meanings related to the terms monomer and polymer?

Answer 30

a monomer is a single subunit; a polymer is a molecule made of many monomers

Question 31

define reactants

Answer 31

substances that are changed during a chemical reactions

Question 32

define products

Answer 32

substances made by a chemical reaction

Question 33

What causes chemical bonds to break during a reaction?

Answer 33

the addition of energy to the reactants

Question 34

What is bond energy?

Answer 34

the energy required to break a bond between 2 atoms

Question 35

In a chemical equation, what symbol is used to show that a chemical reaction goes in both directions?

Answer 35

one arrow on top of another, pointing in opposite directions

Question 36

When does a chemical reaction reach equilibrium?

Answer 36

when a reaction takes place at equal rates in both directions

Question 37

The bond energy of the reactants and products determines whether ...

Answer 37

energy will be released or absorbed during a chemical reaction

Question 38

before a chemical reaction can start, _____ must be absorbed by reactants.

Answer 38

energy

Question 39

What is the amount of energy that must be absorbed to start a reaction called?

Answer 39

activation energy

Question 40

In an exothermic reaction, the products have ...

Answer 40

a lower bond energy than the reactants. overall, energy is released.

Question 41

In an endothermic reaction, the products have ...

Answer 41

a higher bond energy than the reactants. Overall, energy is absorbed.

Question 42

A chemical reaction changes ______ into ______.

Answer 42

reactants into products

Question 43

analogy for activation energy example

Answer 43

the energy it takes to get out of bed in the morning before you can start your day.

Question 44

The term equilibrium is based on two Latin roots that mean "equal" and "balance." How do these meanings tell you the meaning of equilibrium in a chemical reaction?

Answer 44

The reactants and products formed equally; the reaction is in a balanced state.

Question 45

The prefix exo- means "out," and the prefix endo- means "in." What do these prefixes tell you about exothermic and endothermic reactions?

Answer 45

Energy goes out of an exothermic reaction and goes into an endothermic reaction.

Question 46

What is activation energy?

Answer 46

the amount of energy required to start a chemical reaction.

Question 47

A catalyst _____ activation energy.

Answer 47

lowers

Question 48

main functions of catalysts

Answer 48

- catalysts decrease activation energy for a chemical reaction - catalysts increase the rate of a chemical reaction

Question 49

detail about another characteristic of catalysts

Answer 49

catalysts are neither reactants nor products because they are not changed or used up

Question 50

When a catalyst is present, more/less activation energy is needed to start a chemical reaction.

Answer 50

less activation energy

Question 51

Why are enzymes necessary?

Answer 51

because reactions in organisms have to occur at a low temperature (body temp), with low concentrations of reactants and at a high rate.

Question 52

How does the structure of enzymes affect their function?

Answer 52

if structure changes, substrates will not be able to bind an enzyme's active sites

Question 53

Lock and key model for enzymes

Answer 53

only certain substrates bind to an enzyme's active sites; when bound to the enzyme the chemical reaction can occur

Question 54

Important factors in enzyme structure

Answer 54

order of amino acids and hydrogen bonding between the amino acids

Question 55

How do enzymes weaken the bonds in substrates?

Answer 55

the enzyme's shape changes slightly, which strains the bonds inside the substrate. the strain on the bonds weakens them.

Question 56

The word catalyst comes from the Greek word meaning "to dissolve." How does this definition relate to the meaning of catalyst?

Answer 56

A catalyst "dissolves" or "gets rids of" some of the activation energy needed to start a reaction.

Question 57

How are substrates like keys and enzymes like locks?

Answer 57

specific substrates fit exactly into the active sites for specific enzymes, in a similar way that only a certain key will open any given lock

Question 58

Why is the size of a cell important when looking at surface area?

Answer 58

cells need a high surface area to volume ratio because of food, waste, and metabolic reactions

Question 59

Why is the cell membrane described using the fluid mosaic model?

Answer 59

fluid means moving and that relates to the cell membrane

Question 60

water is ____ , oil is ________, and phospholipids are _______.

Answer 60

hydrophilic; hydrophobic; amphiphilic

Question 61

How is cholesterol used by cells?

Answer 61

cholesterol can function to connect phosopholipids to keep them from getting too warm

Question 62

What is the difference between peripheral and integral proteins?

Answer 62

integral proteins are embedded in the membrane, whereas peripheral proteins are on the surface of the membrane

Question 63

name 1 integral protein

Answer 63

channel proteins

Question 64

name 1 peripheral protein

Answer 64

receptor/signal proteins

Question 65

When carbohydrates bind to proteins, they are known as ...

Answer 65

glycoproteins

Question 66

When carbohydrates bind to lipids, they are known as...

Answer 66

glycolipids