Chapter 3

Question 1

second law of thermodynamics

Answer 1

the universe tends toward disorder

Question 2

entropy

Answer 2

thermodynamic quantity that measures the degree of disorder in a system

Question 3

___ is energy in its most disordered form

Answer 3

heat

Question 4

first law of thermodynamics

Answer 4

energy cannot be created or destroyed

Question 5

first stage of photosynthesis

Answer 5

energy from sunlight is captured and transiently stored as chemical-bond energy in activated carriers

Question 6

second stage of photosynthesis

Answer 6

activated carriers are used to help drive a carbon-fixation process, in which sugars are manufactured from CO2

Question 7

oxidation

Answer 7

removal of electrons from an atom
LEO

Question 8

reduction

Answer 8

addition of electrons to an atom
GER

Question 9

oxidized

Answer 9

donate a pair of electrons

Question 10

reduced

Answer 10

accept a pair of electrons

Question 11

which of these if produced by cell respiration, and what state of carbon does this by-product represent?
-CO2;completely oxidized carbon
-CO2;reduced version of carbon
-C6H12O6;completely oxidized carbon
-C6H12O6;reduced version of carbon

Answer 11

CO2; completely oxidized carbon

Question 12

Which statement is true?
-A cell generates order by decreasing the entropy of its surroundings
-Cells obey the first law of thermodynamics but are exempt from the second law
-A cell takes in heat from the environment to power its biosynthetic reactions, thereby obeying the second law of thermodynamics
-The heat released by an animal cell comes from the chemical bond energy present in the food molecules it metabolizes

Answer 12

the heat released by an animal cell comes from the chemical bond energy present in the food molecules it metabolizes

Question 13

enzyme

Answer 13

a protein that catalyzes a specific chemical reaction by lowering the activation energy

Question 14

free energy (G)

Answer 14

energy that can be harnessed to do work or drive chemical reactions

Question 15

catalyst

Answer 15

substance that accelerates a chemical reaction by lowering its activation energy

Question 16

enzymes molecules are _____ after participating in a reaction

Answer 16

unchanged

Question 17

Energetically favorable reactions create disorder by _____ the free energy and have a _____ G

Answer 17

decreasing
negative

Question 18

a reaction only occurs if G is _____

Answer 18

negative

Question 19

energetically unfavorable reactions create ____ in the universe and have a _____ G

Answer 19

order
positive

Question 20

equilibrium

Answer 20

forward and reverse rates of a chemical reaction are equal
G=0

Question 21

Delta G equation

Answer 21

delta G = delta G of formation + RTln(X/Y)

Question 22

equilibrium constant

Answer 22

K=[X]/[Y]
K=[AB]/[A][B]

Question 23

the _____ finds its ____
enzyme & substrate

Answer 23

substrate
enzyme

Question 24

______ formation is what prevents unwanted associations from forming between mismatched molecules

Answer 24

poor noncovalent bond

Question 25

small molecules diffuse through the cytosol very efficiently by...

Answer 25

moving randomly, knocked around by colliding with other molecules

Question 26

which is not true of a chemical reaction at equilibrium? -delta G = 0 -the rates of the forward and reverse reactions are equal -the net concentrations of substrate and product do not change -both the forward and reverse reactions have stopped

Answer 26

both the forward and reverse reactions have stopped

Question 27

at equilibrium, the free-energy change for a reaction is which of the following? -at its highest point -energetically unfavorable -equal to delta G of formation -zero in both forward and reverse directions

Answer 27

zero in both forward and reverse directions

Question 28

activated carriers

Answer 28

small molecule that stores energy or chemical groups in a form that can be donated to many different metabolic reactions

Question 29

an energetically _____ reaction is used to drive an energetically _____ one

Answer 29

favorable unfavorable

Question 30

ATP is synthesized in an energetically _____ _______ reaction in which a _____ is added to ADP

Answer 30

unfavorable phosphorylation phosphate group

Question 31

ATP gives up the energy packet in an energetically ____ ______ to ADP and phosphate

Answer 31

favorable hydrolysis

Question 32

phosphorylation is an example of a ______ reaction

Answer 32

condensation

Question 33

Both NADH and NADPH carry energy in the form of two ______ plus a _____, which together form a hydride ion

Answer 33

high-energy electrons proton

Question 34

NADH and NADPH become _____ to form NAD+ and NADP+ when they pass their ____ to a donor molecule

Answer 34

oxidized hydride ion

Question 35

plenty of NAD+ to act as a(n) _______ agent and NAPDH to act as a(n) _____ agent

Answer 35

oxidizing reducing

Question 36

which of these represents a carrier in the activated state in which it would be used in the cell? -ADP -NADP -FAD -NADH

Answer 36

NADH

Question 37

which reaction can be driven by the hydrolysis of a molecule of ATP inside a cell? -sucrose->glucose + fructose (-G) -glucose+oxygen->CO2+water (-G) -CO2+water->glucose+oxygen (+G) -glucose+fuctose->sucrose (+G)

Answer 37

glucose + fructose -> sucrose (+G)

Question 38

the ultimate source of energy for most organism is _____

Answer 38

the sun

Question 39

catabolic reactions

Answer 39

release energy by breaking down organic molecules

Question 40

anabolic reactions

Answer 40

require an energy input to generate organic molecules