Chapter 8: An Introduction to Metabolism

Question 1

is a miniature chemical factory where
thousands of reactions occur

Answer 1

the living cell

Question 2

extracts energy stored in sugars
and other fuels

Answer 2

cellular respiration

Question 3

Cells apply this energy to perform work

Answer 3

the energy produced for cellular respiration

Question 4

is the totality of an organism’s chemical reactions

Answer 4

metabolism

Question 5

is an emergent property of life that arises from orderly interactions between molecules

Answer 5

metabolism

Question 6

begins with a specific molecule and ends with a product

Answer 6

metabolic pathway

Question 7

release energy by breaking down complex molecules into simpler compounds

Answer 7

catabolic pathways

Question 8

an example of catabolic pathways is

Answer 8

Cellular respiration, the breakdown of glucose
in the presence of oxygen,

Question 9

consume energy to build
complex molecules from simpler ones

Answer 9

anabolic pathways

Question 10

example of anabolic pathways

Answer 10

the synthesis of protein from amino
acids

Question 11

is the study of how energy flows
through living organisms

Answer 11

bioenergetics

Question 12

is the capacity to cause change

Answer 12

energy

Question 13

Energy associated with motion

Answer 13

kinetic energy

Question 14

is the kinetic energy associated with
random movement of atoms or molecules

Answer 14

thermal energy

Question 15

is thermal energy in transfer between objects

Answer 15

heat

Question 16

is energy that matter possesses
because of its location or structure

Answer 16

potential energy

Question 17

is potential energy available for release in a chemical reaction

Answer 17

chemical energy

Question 18

is the study of energy
transformations

Answer 18

thermodynamics

Question 19

is unable to exchange energy or
matter with its surroundings

Answer 19

isolated system

Question 20

energy and matter can be
transferred between the system and its surroundings

Answer 20

open system

Question 21

what kind of systems are organisms

Answer 21

open

Question 22

proceeds with a net release of free energy and is spontaneous

Answer 22

exergonic reaction

Question 23

absorbs free energy from its surroundings and is non spontaneous

Answer 23

endergonic reactions

Question 24

what happens to reactions in closed systems

Answer 24

eventually reach equilibrium and can then do no work

Question 25

what is special ab metabolism in life

Answer 25

it is never at equilibrium

Question 26

three main kinds of work

Answer 26

chemical transport mechanical

Question 27

pushing endergonic reactions

Answer 27

chemical work

Question 28

pumping substances against the direction of spontaneous movement

Answer 28

transport work

Question 29

contraction of muscle cells

Answer 29

mechanical work

Question 30

how cell manage energy resources

Answer 30

energy coupling

Question 31

the use of an exergonic process to drive an endergonic one

Answer 31

energy coupling

Question 32

most energy coupling is meditated by what

Answer 32

ATP

Question 33

the chemical breakdown of a compound due to reaction with water.

Answer 33

hydrolysis

Question 34

how is cellular work powered?

Answer 34

hydrolysis of ATP

Question 35

what can be used to drive an endergonic reaction

Answer 35

the energy from the exergonic reaction of ATP hydrolysis

Question 36

transferring a phosphate group to some other molecule, such as a reactant

Answer 36

phosphorylation

Question 37

how does ATP drive endergonic reactions?

Answer 37

phosphorylation

Question 38

the molecule that receives the phosphate group is called

Answer 38

phosphorylated intermediate

Question 39

is a renewable resource that is regenerated by addition of a phosphate group to adenosine diphosphate ()

Answer 39

ATP

Question 40

what regenerates ATP?

Answer 40

addition of a phosphate group to adenosine diphosphate (ADP) (phosphorylate - ing the ATP)

Question 41

where does the energy come to phosphorylate ATP come from

Answer 41

catabolic reactions

Question 42

is a chemical agent that speeds up a reaction without being consumed by the reaction

Answer 42

catalyst

Question 43

is a catalytic protein

Answer 43

enzyme

Question 44

Every chemical reaction between molecules involves what

Answer 44

bond breaking and bond forming

Question 45

The initial energy needed to start a chemical reaction is called the free energy of activation, or

Answer 45

activation energy (EA)

Question 46

often supplied in the form of thermal energy that the reactant molecules absorb from their surroundings

Answer 46

activation energy (EA)

Question 47

speed up specific reactions by lowering the EA barrier

Answer 47

catalysis

Question 48

hasten reactions that would occur eventually

Answer 48

enzymes

Question 49

The reactant that an enzyme acts on is called the enzyme’s

Answer 49

substrate

Question 50

The enzyme binds to its substrate, forming an

Answer 50

enzyme-substrate complex

Question 51

example of a enzyme

Answer 51

sucrase

Question 52

how is activation energy often supplied

Answer 52

thermal energy

Question 53

how do catalysis speed up specific reactions

Answer 53

by lowering the activation energy barrier

Question 54

is the region on the enzyme where the substrate binds

Answer 54

active site

Question 55

brings chemical groups of the active site into positions that enhance their ability to catalyze the reaction

Answer 55

induced fit of a substrate

Question 56

The active site can lower an EA barrier by what

Answer 56

orienting substrates correctly straining substrate bonds providing a favorable microenvironment covalently bonding to the substrate

Question 57

how can the rate of enzyme-catalyzed reaction can be sped up

Answer 57

increasing substrate

Question 58

When all enzyme molecules have their active sites engaged, the enzyme is what

Answer 58

saturated

Question 59

how do you speed up a saturated reaction rate

Answer 59

adding more enzyme

Question 60

An enzyme’s activity can be affected by

Answer 60

- general environmental factors, such as temperature and pH - chemicals that specifically influence the enzyme

Question 61

are nonprotein enzyme helpers

Answer 61

cofactors

Question 62

An organic cofactor is called a

Answer 62

coenzyme

Question 63

bind to the active site of an enzyme, competing with the substrate

Answer 63

Competitive inhibitors

Question 64

bind to another part of an enzyme, causing the enzyme to change shape and making the active site less effective

Answer 64

Noncompetitive inhibitors

Question 65

examples of inhibitors

Answer 65

toxins, poisons, pesticides, and antibiotics

Question 66

Chemical chaos would result if what

Answer 66

a cell’s metabolic pathways were not tightly regulated

Question 67

may either inhibit or stimulate an enzyme’s activity

Answer 67

Allosteric regulation

Question 68

occurs when a regulatory molecule binds to a protein at one site other than the enzyme’s active site and affects the protein’s function at another site

Answer 68

Allosteric regulation

Question 69

most allosterically regulated enzymes are made from

Answer 69

polypeptide subunits

Question 70

stabilizes the active form of the enzyme

Answer 70

The binding of an activator

Question 71

stabilizes the inactive form of the enzyme

Answer 71

The binding of an inhibitor

Question 72

is a form of allosteric regulation that can amplify enzyme activity

Answer 72

cooperativity

Question 73

what is the exception for cooperativity

Answer 73

the substrate itself is the regulator and regulation is induced by binding in one of the active sites

Question 74

how is cooperativity allosteric

Answer 74

because binding by a substrate to one active site affects catalysis in a different active site

Question 75

the end product of a metabolic pathway shuts down the pathway

Answer 75

feedback inhibition

Question 76

prevents a cell from wasting chemical resources by synthesizing more product than is needed

Answer 76

Feedback inhibition