Chapter 8

Front 1

is the totality of an organism’s chemical reactions

Back 1

Metabolism

Front 2

A ____ _____ begins with a specific molecule and ends with a product

Back 2

metabolic pathways

Front 3

release energy by breaking down complex molecules into simpler compounds

Back 3

Catabolic pathways

Front 4

consume energy to build complex molecules from simpler ones

example : synthesis of protein

Back 4

Anabolic pathways

Front 5

is the study of how organisms manage their energy resources

Back 5

Bioenergetics

Front 6

the capacity to cause change

Back 6

Energy

Front 7

is energy associated with motion

Back 7

Kinetic energy

Front 8

kinetic energy associated with random movement of atoms or molecules

Back 8

Heat (thermal energy)

Front 9

is energy that matter possesses because of its location or structure

Back 9

Potential energy

Front 10

potential energy available for release in a chemical reaction

Back 10

Chemical energy

Front 11

study of energy transformations

Back 11

Thermodynamics

Front 12

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

Back 12

first law of thermodynamics

Front 13

During every energy transfer or transformation, some energy is unusable, and is often lost as heat

Back 13

second law of thermodynamics

Front 14

Every energy transfer or transformation increases the____ of the universe

Back 14

Entropy

Front 15

A living system’s ____ ____ is energy that can do work when temperature and pressure are uniform

Back 15

free energy

Front 16

free energy

(symbol)

Back 16

∆G

Front 17

total energy

(symbol)

Back 17

∆H

Front 18

whats the formula to find free energy

Back 18

∆G = ∆H – T∆S

Front 19

Only processes with a negative ∆G are______

Back 19

Spontaneous

Front 20

_____is a state of maximum stability

Back 20

Equilibrium

Front 21

a net release of free energy and is spontaneous

(reaction)

Back 21

exergonic reaction

Front 22

absorbs free energy from its surroundings and is nonspontaneous

(reaction)

Back 22

endergonic reaction

Front 23

cells three main kinds of work

Back 23

Chemical
Transport
Mechanical

Front 24

adenosine triphosphate

Back 24

ATP

Front 25

cell’s energy shuttle

Back 25

ATP

Front 26

ATP is composed of


(3 things)

Back 26

ribose
adenine
three phosphate groups

Front 27

How is ATP regenerated ?

Back 27

addition of a phosphate group to adenosine diphosphate (ADP)

Front 28

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

(Enzyme)

Back 28

Catalyst

Front 29

initial energy needed to start a chemical reaction

Back 29

activation energy (E_A)

Front 30

reactant that an enzyme acts on

Back 30

substrate

Front 31

when an enzyme binds with to a substrate

Back 31

enzyme-substrate complex

Front 32

4 ways an active site can lower the activation energy(E_A) is :

Back 32

Orienting substrates correctly
Straining substrate bonds
Providing a favorable microenvironment
Covalently bonding to the substrate

Front 33

nonprotein enzyme helpers

Back 33

Cofactors

Front 34

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

Back 34

Competitive inhibitors

Front 35

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

Back 35

noncompetitive inhibitors

Front 36

regulation may either inhibit or stimulate an enzyme’s activity

Back 36

Allosteric regulation

Front 37

the end product of a metabolic pathway that shuts down the pathway

Back 37

feedback inhibition

Front 38

A(n) _______ system, such as that approximated by liquid in a thermos, is isolated from its surroundings

Back 38

isolated

Front 39

In a(n) _______ system, energy and matter can be transferred between the system and its surroundings

Back 39

open

Front 40

Are organisms open or isolated systems?

Back 40

open

Front 41

a measure of a system’s instability, its tendency to change to a more stable state

Back 41

Free energy

Front 42

Reactions in a _______ system eventually reach equilibrium and then do no work

Back 42

closed

Front 43

Are cells in equilibrium? Why or why not?

Back 43

Cells are not in equilibrium; they are open systems experiencing a constant flow of materials

Front 44

Is metabolism ever at equilibrium?

Back 44

No

Front 45

A catabolic pathway in a cell releases __________ in a series of reactions

Back 45

free energy

Front 46

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

Back 46

energy coupling

Front 47

Most energy coupling in cells is mediated by ______

Back 47

ATP

Front 48

Energy is released from ATP when the _____________ is broken

Back 48

terminal phosphate bond

Front 49

What are the three types of cellular work?

Back 49

mechanical, transport, and chemical

Front 50

The three types of cellular work are powered by what?

Back 50

the hydrolysis of ATP

Front 51

ATP drives endergonic reactions by __________, transferring a phosphate group to some other molecule called a(n) ______________, such as a reactant

Back 51

phosphorylation, phosphorylated intermediate

Front 52

Where does the energy to phosphorylate ADP comes from?

Back 52

catabolic reactions in the cell

Front 53

Activation energy is often supplied in the form of _____________ that the reactant molecules absorb from their surroundings

Back 53

thermal energy

Front 54

How do enzymes catalyze reactions?

Back 54

by lowering the E_A barrier

Front 55

Do enzymes affect the change in free energy (∆G)?

Back 55

No; instead, they hasten reactions that would occur eventually

Front 56

the region on the enzyme where the substrate binds

Back 56

active site

Front 57

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

Back 57

Induced fit

Front 58

What can an enzyme’s activity be affected by? (2 things)

Back 58

- General environmental factors, such as temperature and pH

-Chemicals that specifically influence the enzyme

Front 59

An organic cofactor

Back 59

coenzyme

Front 60

a form of allosteric regulation that can amplify enzyme activity

Back 60

Cooperativity

Front 61

Inhibition of proteolytic enzymes called ________ may help management of inappropriate inflammatory responses

Back 61

caspases

Front 62

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

Back 62

Feedback inhibition

Front 63

An organism’s metabolism transforms _______ and ________, subject to the laws of thermodynamics.

Back 63

matter and energy

Front 64

The free-energy change of a reaction tells us whether or not the reaction occurs ___________.

Back 64

spontaneously

Front 65

How does ATP powers cellular work?

Back 65

by coupling exergonic reactions to endergonic reactions

Front 66

How do enzymes speed up metabolic reactions?

Back 66

by lowering energy barriers

Front 67

Regulation of enzyme activity helps control _________.

Back 67

metabolism