Chapter 6

Question 1

cells obtain energy from ______ using _______ and apply the energy to ______

Answer 1

sugar, cellular respiration, perform work

Question 2

metabolism

Answer 2

totality of an organism’s chemical reactions

Question 3

metabolism is an emergent property that arises from?

Answer 3

orderly interactions between molecules

Question 4

metabolic pathway

Answer 4

begins with specific molecules and ends with a product

Question 5

each step of the metabolic pathway is?

Answer 5

catalyzed by a specific enzyme

Question 6

catabolic pathway

Answer 6

release energy by breaking complex molecules into simpler compounds.

Question 7

anabolic pathway

Answer 7

consume energy to build complex molecules from simpler ones.

Question 8

anabolic pathway is also called?

Answer 8

biosynthetic pathway

Question 9

bioenergentics

Answer 9

study of how energy flows through living organisms.

Question 10

energy

Answer 10

capacity to cause change

Question 11

work is the movement of?

Answer 11

matter against opposing forces

Question 12

thermal energy

Answer 12

kinetic energy associated with random movement of molecules.

Question 13

heat

Answer 13

thermal energy in transfer from one object to another

Question 14

chemical energy

Answer 14

potential energy available for release in a chemical reaction

Question 15

thermodynamics

Answer 15

study of energy transformations

Question 16

Organisms are ____ systems

Answer 16

open

Question 17

first law of thermodynamics

Answer 17

energy cannot be created or destroyed

Question 18

the first law of thermodynamics is also called?

Answer 18

principle of conservation of energy

Question 19

second law of thermodynamics

Answer 19

every energy transformation increases entropy of the universe

Question 20

heat ____ the disorder of the surroundings

Answer 20

increases

Question 21

scientists use the term disorder to? (2)

Answer 21

-show how dispersed energy is in a system
-show how many energy levels are present

Question 22

spontaneous process occurs without?

Answer 22

energy input

Question 23

For a process to occur spontaneously it must?

Answer 23

increase the entropy of the universe

Question 24

Individual cells and whole organisms create?

Answer 24

ordered structures from disorganized starting materiel

Question 25

free energy

Answer 25

portion of a system's energy that can do work when temp and pressure are constant.

Question 26

A process is spontaneous and can perform work only?

Answer 26

when it is moving towards equilibrium

Question 27

exergonic reaction

Answer 27

proceeds with release of free energy

Question 28

exergonic reaction is ________ and Delta g is _____?

Answer 28

spontaneous, -

Question 29

endergonic reaction

Answer 29

absorbs free energy from its surroundings

Question 30

endergonic reaction is _______ and Delta g is _____?

Answer 30

nonspontaneous, +

Question 31

the magnitude of Delta g is?

Answer 31

the quantity of energy required to drive a reaction

Question 32

Reactions in an isolated system eventually?

Answer 32

reach equilibrium and can do no work.

Question 33

One of the defining features of life

Answer 33

metabolism as a whole is never at equilibrium

Question 34

What prevents a system from reaching equilibrium?

Answer 34

the product of each reaction is the reactant for the next.

Question 35

A cell does 3 main kinds of work.

Answer 35

-chemical -transport -mechanical

Question 36

energy coupling

Answer 36

the use of an exergonic process to drive an endergonic one

Question 37

Most energy coupling in cells is mediated by?

Answer 37

ATP

Question 38

ATP (adenosine triphosphate) is composed of

Answer 38

ribose, adenine,and a chain of 3 phosphate groups

Question 39

the bonds between the phosphate groups of ATP can be broken by?

Answer 39

hydrolysis

Question 40

ATP hydrolysis releases?

Answer 40

energy, ADP, and inorganic phosphate

Question 41

the energy released during ATP hydrolysis comes from?

Answer 41

chemical changes to a state of lower free energy

Question 42

Why does ATP hydrolysis releases so much energy?

Answer 42

there is a repulsive force from the 3 negatively charged phosphate groups.

Question 43

The triphosphate tail of ATP is the chemical equivalent to?

Answer 43

compressed spring

Question 44

the chemical work in a cell is powered by?

Answer 44

ATP hydrolysis

Question 45

ATP drives endergonic reactions by?

Answer 45

phosphorylation

Question 46

Phosphorylation

Answer 46

transferring a phosphate group to another molecule

Question 47

The recipient molecule from phosphorylation is called?

Answer 47

phosphorylated intermediate

Question 48

Overall the coupled reactions in ATP hydrolysis are?

Answer 48

exergonic

Question 49

ATP hydrolysis leads to? (2)

Answer 49

-change in proteins shape -affects its ability to bond to other molecules

Question 50

The energy to phosphorylate ADP comes from?

Answer 50

catabolic reactions in the cell

Question 51

catalyst

Answer 51

speeds up a reaction without being consumed

Question 52

enzyme

Answer 52

macromolecule that acts as a catalyst

Question 53

most enzymes are ___?

Answer 53

proteins

Question 54

Activation energy

Answer 54

energy required to start a reaction by breaking bonds

Question 55

Instead of relying on heat, organisms carry out _____ to speed up reactions.

Answer 55

catalysis

Question 56

Enzymes do not affect?

Answer 56

the change in free energy (Delta G)

Question 57

Enzymes are ____ for the reactions they catalyze?

Answer 57

specific

Question 58

substrate

Answer 58

reactant molecule on which an enzyme acts

Question 59

Most enzymes names end in?

Answer 59

ase

Question 60

active site

Answer 60

region that the substrate binds to the enzyme

Question 61

Enzyme specificity results from the fit between?

Answer 61

the shape of the active site and substrate

Question 62

Induced fit

Answer 62

substrate binds to an active site and both change shape slightly, creating an ideal fit for catalysis

Question 63

Substrates are held to an enzyme's active site by?

Answer 63

weak interactions

Question 64

example of weak interactions

Answer 64

hydrogen bonds

Question 65

Saturated Enzyme

Answer 65

All enzyme molecules in a solution are bonded with substrate.

Question 66

an enzymes activity can be affected by? (2)

Answer 66

-temperature and pH -chemicals that influence the enzyme

Question 67

Each enzyme has a ______ and ______ at which the reaction rate is the greatest.

Answer 67

optimal temperature, pH

Question 68

Cofactors

Answer 68

carry out processes difficult for amino acids

Question 69

Cofactors are _____ molecules.

Answer 69

non protein

Question 70

Coenzyme

Answer 70

organic cofactor

Question 71

What often act as coenzymes or the raw material coenzymes are made out of?

Answer 71

vitamins

Question 72

competitive inhibitor

Answer 72

binds to the active site and prevents substrate from binding

Question 73

noncompetitive inhibitor

Answer 73

binds to an alternate site causing the active site to change shape.

Question 74

Irreversible enzyme inhibitor examples

Answer 74

poison and toxin

Question 75

under certain circumstances an altered __ might be favorable.

Answer 75

enzyme

Question 76

Allosteric regulation

Answer 76

inhibit or stimulate an enzyme's activity

Question 77

allosteric regulation occurs when

Answer 77

a regulatory molecule binds to a protein at one site but affects the proteins function at another site.

Question 78

the enzyme complex oscillates between?

Answer 78

active and inactive shapes

Question 79

binding of an activator molecule ___ the active shape.

Answer 79

stabilizes

Question 80

cooperativity

Answer 80

binding of one substrate molecule to the active site of one sub unit locking the other sub units in shape

Question 81

feedback inhibition

Answer 81

end product of a metabolic pathway shuts down the pathway

Question 82

feedback inhibition prevents a cell from ______ by _______

Answer 82

wasting chemical energy, synthesizing more product than is needed