Lecture 4

Question 1

T/F: a spontaneous reaction occurs rapidly

Answer 1

false

Question 2

T/F: non-spontaneous reactions do not occur

Answer 2

false

Question 3

H is less than 0

Answer 3

exothermic, release energy

Question 4

H > 0

Answer 4

endothermic, requires energy

Question 5

the linked reactions in a pathway and steady states prevent – in cells

Answer 5

accumulation of excess intermediates

Question 6

pH of interior of cell

Answer 6

7

Question 7

half of molecule donates protons at

Answer 7

pKa

Question 8

the charge on amino acid side chains depend on the

Answer 8

pH

Question 9

spontaneous drives toward

Answer 9

disorder

Question 10

greater disorder, greater –

Answer 10

entropy

Question 11

1st law of thermodynamics

Answer 11

energy can be converted from one form to another, but the total energy must always be the same

Question 12

an enzyme lowers the – and increases –

Answer 12

activation energy, rate of chemical reaction

Question 13

T/F: enzymes can change equilibrium point for reactions

Answer 13

false

Question 14

energetically unfavorable reactions can be driven by energetically favorable reactions if the net free-energy change for the pair of coupled reactions is

Answer 14

less than 0

Question 15

Enzyme catalysis directs substrates through a – reaction pathway

Answer 15

specific

Question 16

photosynthesis

Answer 16

reduce CO2 and H2O to make carbohydrates

store energy in form of chemical bonds

Question 17

cellular respiration

Answer 17

oxidize carbohydrates –> release energy as CO2 and H2O = lowest energy state

Question 18

In the presence of – the most energetically stable form of carbon is CO2 and that of hydrogen is H2O

Answer 18

oxygen

Question 19

CO2 is restored to the atmosphere when organic molecules are oxidized by cells or burned as fuels

Answer 19

carbon cycle

Question 20

– store energy in an easily exchangeable form

Answer 20

activated carriers

Question 21

the useful energy in ATP is contained in

Answer 21

phosphoanhydride bonds

Question 22

– is the most widely used activated carrier

Answer 22

ATP

Question 23

dG for hydrolysis of ATP to ADP and Pi is

Answer 23

-46 – -54 kJ/mole

Question 24

dG for hydrolysis of ATP to AMP and pyrophosphate is

Answer 24

-100 kJ/mole

Question 25

in addition to ATP, – and – are important activated electron carriers in glycolysis and respiration

Answer 25

NADH and NADPH

Question 26

NADH is the – form

Answer 26

reduced form that stores high energy

Question 27

NAD+ is the – form

Answer 27

oxidized form

Question 28

an important activated carrier that is the intermediate for many biosynthesis pathways

Answer 28

acetyl CoA

Question 29

the synthesis of RNA or DNA is driven by –

Answer 29

ATP hydrolysis

Question 30

each monomer carries a high-energy bond that will be used for the addition of the next monomer

Answer 30

head polymerization

Question 31

each monomer carries a high-energy bond for its own addition

Answer 31

tail polymerization

Question 32

head polymerization macromolecule

Answer 32

protein

Question 33

tail polymerization macromolecule

Answer 33

RNA and DNA

Question 34

cells generate ATP through

Answer 34

controlled stepwise oxidation of sugar in a cell

Question 35

charge on amino acid side chains depends on the

Answer 35

pH

Question 36

At a pH below its pka, an acid will be

Answer 36

protonated

Question 37

– drive the synthesis of the majority of ATP in most cells

Answer 37

oxidative phosphorylation

Question 38

the complete oxidation of a molecule of glucose to H2O and CO2 producers – molecules of ATP

Answer 38

30

Question 39

– is where acetyl CoA is produced from food molecules

Answer 39

mitochondria

Question 40

sugars —> ___ –> acetyl CoA

Answer 40

pyruvate

Question 41

fat –> __ –> acetyl CoA

Answer 41

fatty acids