Chapter 8

Front 1

____ is the totality of an organism's chemical reactions

Back 1

Metabolism

Front 2

Metabolism is an _____ of life that arises from interaction between molecules within the cell

Back 2

emergent property

Front 3

Metabolic pathway

Back 3

begins with a specific molecule and ends with a product

Front 4

*Each step of the metabolic pathway is

Back 4

catalyzed by a specific enzyme

Front 5

_______ Releases energy by breaking down complex molecules into simpler compounds

Back 5

Catabolic pathways

Front 6

______ the breakdown of glucose in the presence of oxygen, is an example of a pathway of catabolism

Back 6

cellular respiration

Front 7

____ consume energy to build complex molecules from simpler ones (Biosynthetic pathways)

Back 7

Anabolic pathways

Front 8

Synthesis of proteins from amino acids is an example of

Back 8

anabolism

Front 9

_____ is the study of how organisms manage their energy resources

Back 9

Bioenergetics

Front 10

*____ is the capacity to cause change

Back 10

Energy

Front 11

____ is energy assiciated with motion

Back 11

Kinetic energy

Front 12

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

Back 12

Heat(Thermal energy)

Front 13

_____is energy that matter possesses because of its location or structure

Back 13

Potential energy

Front 14

_____ is potential energy available for release in a chemical reaction

Back 14

Chemical energy

Front 15

____ is the study of energy transformations

Back 15

Thermodynamics

Front 16

Word _____ to denote the matter under study

Back 16

system

Front 17

________ such as that approximated by liquid in a thermos, is isolated from its surroundings

Back 17

isolated system

Front 18

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

Back 18

Open system

Front 19

_____ are open systems

Back 19

organisms

Front 20

First law of thermodynamics

Back 20

Energy can be transferred and transformed, but it cannot be created or destroyed

Front 21

The first law is also called the

Back 21

principle of conservation of energy

Front 22

Second law of thermodynamics

Back 22

every energy transfer or transformation increases the entropy (disorder) of the universe

Front 23

living cells unavoidably convert

Back 23

organized forms of energy to heat

Front 24

_____ occurs without energy input; they can happen quickly or slowly

Back 24

Spontaneous processes

Front 25

For a process to occur without energy input, it must

Back 25

increase the entropy of the universe

Front 26

Energy flows into an ecosystem in the form of

Back 26

light and exits in the form of heat

Front 27

wntropy may decrease in an organism

Back 27

but the universe's total entropy increases

Front 28

organism are islands of low entropy in an

Back 28

increasing random universe

Front 29

A living system's ______ is energy that can do work when temperatures and pressure are uniform, as in a living cell

Back 29

free energy

Front 30

The change in free energy (DeltaG) during a process is related to the

Back 30

change in enthalpy, or change in total energy(DeltaH), change in entropy(DeltaS), and temperature in Kelvin (T)

Front 31

only processes with a negative DeltaG are

Back 31

spontaneous

Front 32

Spontaneous processes can be harnessed to

Back 32

perform work

Front 33

free energy is a measure of a

Back 33

system's instability, its tendency to change to a more stable state

Front 34

during a spontaneous change,

Back 34

free energy decreases and the stability of a system increases

Front 35

_____ is a state of maximum stability

Back 35

Equilibrium

Front 36

a process is spontaneous and can perform work only when

Back 36

its moving toward equilibrium

Front 37

_______ proceeds with a net release of free energy and is spontaneous (energy outward)

Back 37

exergonic reactions

Front 38

_______ absorbs free energy from its surroundings and is non-spontaneous (energy inward)

Back 38

Endergonic reaction

Front 39

Reactions in a closed system eventually reach

Back 39

equilibrium and then do not work

Front 40

Cells are not in equilibrium; they are

Back 40

open systems experiencing a constant flow of materials

Front 41

A defining feature of life is that

Back 41

metabolism is never at equilibrium

Front 42

Catabolic pathway in a cell releases

Back 42

free energy in a series of reactions

Front 43

Closed and open hydroelectric systems can

Back 43

serve as analogies

Front 44

A cell does three main kinds of work:

Back 44

-Chemical

-Transport

-Mechanical

Front 45

to do work, cells manage resources by _______, the use of an exergonic process to drive an endergonic one

Back 45

energy coupling

Front 46

most energy coupling in cells is mediated by

Back 46

ATP

Front 47

_____ is the cell's energy shuttle

Back 47

ATP (adenosine triphosphate)

Front 48

ATP is composed of

Back 48

ribose, adenine, and three phosphate groups

Front 49

The bonds between the phosphate groups of ATP's tail can be broken by

Back 49

hydrolisis

Front 50

Energy is released from ATP when

Back 50

the terminal phosphate bond is broken

Front 51

This release of energy comes from the __________

Back 51

Chemical change to a state of lower free energy, not from the phosphate bonds themselves

Front 52

The three types of cellular work (mechanical,transport, and chemical) are

Back 52

powered by the hydrolysis of ATP

Front 53

In the cell, the energy from the exergonic reaction of ATP hydrolisis can be

Back 53

used to drive an endergonic reaction

Front 54

ATP is a renewable resource that is regenerated by

Back 54

addition of a phosphate group to adenosine diphosphate (ADP)

Front 55

The energy to phosphorylate ADP comes from

Back 55

catabolic reactions in the cell

Front 56

The ATP cycles is a revolving door through which energy

Back 56

passes during its transfer from catabolic to anabolic pathways

Front 57

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

Back 57

catalyst

Front 58

____ is a catalytic protein

Back 58

enzyme

Front 59

Hydrolysis of sucrose by the enzyme sucrase is an example of

Back 59

an enzyme-catalyzed reaction

Front 60

Every chemical reaction between molecules involves

Back 60

bond breaking and bond forming

Front 61

The initial energy needed to start a chemical reaction is called

Back 61

free energy of activation, or activation energy(Ea); the energy required to contort the reactant molecules so the bonds can break

Front 62

______ is often supplied in the form of ______ that the reactant molecules absorb from their surroundings

Back 62

Activation energy, thermal energy

Front 63

Enzymes catalyze reactions by

Back 63

lowering the Ea barrier

Front 64

The reactant that an enzyme acts on is called the enzyme's ______

Back 64

Substrate

Front 65

The enzyme binds to its substrate, forming an _____

Back 65

enzyme-substrate complex

Front 66

The ______ is the region on the enzyme where the substrate binds

Back 66

Active site

Front 67

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

Back 67

Induced fit

Front 68

In an enzymatic reaction, the substrate

Back 68

binds to the active site of the enzyme

Front 69

The active site can lower an Ea barrier by:

Back 69

-Orienting substrates correctly

-Straining substrate bonds and stabilizing the transition state

-Providing a favorable microenvironment

-Covalently bonding to the substrate

Front 70

An enzyme's activity can be affected by:

Back 70

-General environmental factors, such as temperatues and pH

-Chemical that specifically influence the enzymes

Front 71

Each enzyme has

Back 71

-an optimal temperature in which it can function

-an optimal pH which it can function

-optimal conditions favor the most active shape for the enzymes molecule

Front 72

Prosthetic groups:

Back 72

Non-amino acid groups bound to enzymes (Flavin nucleotide which binds to succinate dehygrogenase)

Front 73

Cofactors:

Back 73

inorganic ions such as copper, zinc and iron

Front 74

Coenzymes:

Back 74

small carbon-containing molecules; not bound permanently to enzymes

Front 75

Cofactors are:

Back 75

-nonprotein enzymes helpers

-may be inorganic (such as a metal in ionic form) or organic

-An organic cofactor is called a coenzyme

-Coenzymes include vitamins

Front 76

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

Back 76

competitive inhibitors

Front 77

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

Back 77

Non competitive inhibitors

Front 78

Chemical chaos would result if a cell's

Back 78

-metabolic pathways were not tightly regulated

-A cell does this by switching on or off the genes that encode specific enzymes or by regulating the activity of enzymes

Front 79

______ may either inhibit or stimulate an enzyme's activity

Back 79

Allosteric regulation

Front 80

Most allosterically regulated enzymes are made from

Back 80

polypeptide subunits

Front 81

The binding of an activator

Back 81

stabilizes the active form of the enzyme

Front 82

The binding of an inhibitor

Back 82

stabilizes the inactive form of the enzyme

Front 83

_____ is a form allosteric regulation that can amplify enzyme activity

Back 83

cooperativity

Front 84

One substrate molecule primes an enzyme to

Back 84

act on additional substrate molecules more readily

Front 85

Cooperativity is allosteric because binding by a substrate

Back 85

to an active side affects catalyst in a different active site

Front 86

_______, the end product of a metabolic pathways shuts down the pathway

Back 86

feedback inhibition

Front 87

Feedback inhibition prevents a cell from

Back 87

wasting chemical resources by synthesizing more product than is needed

Front 88

Structures within the cell help bring

Back 88

order to metabolic pathways

Front 89

Some enzymes act as

Back 89

Structural components of membranes

Front 90

In eukaryotic cells, reside in specific organelles;

Back 90

for example enzymes for cellular respiration are located in mitochondria