Chapter 9: Cellular Respiration And Fermentation

Front 1

Energy flows into an ecosystem as _________ and ultimately leaves as __________

Back 1

Sunlight

Heat

Front 2

A partial degredation of sugars or other organic fuel that occurs without the use of oxygen.

Back 2

Fermentation

Front 3

The most efficient catabolic pathway?

Back 3

Aerobic respiration

Front 4

Oxygen is consumed as a reactant along with the organic fuel?

Back 4

Aerobic Respiration

Front 5

The harvesting of chemical energy without oxygen?

Back 5

Anaerobic Respiration

Front 6

Cellular respiration technically refers to _________ but is primarily synonymous for ________

Back 6

Aerobic and Anaerobic processes

Aerobic Processes

Front 7

Process of aerobic reaction?

Back 7

Organic Compounds + Oxygen -> Carbon Dioxide + Energy

Front 8

Degradation of glucose?

Back 8

C6H12O6 + 6 O2 -> 6 CO2 + 6 H2O + Energy (ATP & Heat)

Front 9

Is the breakdown of glucose an exergonic or endergonic reaction?

Back 9

Exergonic (-686 kcal/mol)

Front 10

How do the catabolic pathways that decompose glucose and other organic fuels yield energy?

Back 10

The transfer of electrons during chemical reactions releases energy stored in organic molecules, this energy is ultimately used to synthesize ATP.

Front 11

Oxidation-reduction reactions (redox reactions)

Back 11

The transfer of one or more electrons (e-) from one reactant to another.

Front 12

The loss of electrons from one substance in a redox reaction?

Back 12

Oxidation

Front 13

The addition of electrons to another substance in a redox reaction?

Back 13

Reduction

Front 14

Reducing agent

Back 14

The electron donor of a redox reaction

Front 15

Oxidizing agent

Back 15

The acceptor of electrons in a redox reaction

Front 16

Redox reaction between Methane and Oxygen

Define the

(a) Reactants

(b) Products

(c) Reducing agent

(d) Oxidizing Agent

(e) Becomes oxdized

(f) Becomes Reduced

Back 16

Front 17

Which is oxidized and which is reduced?

(a) NAD+

(b) NADH

Back 17

(a) oxidized

(b) reduced

Front 18

Coenzyme that acts as an electron carrier

Back 18

Nicotinamide adenine dinucleotide (NAD+)

Front 19

How does NAD+ trap electrons from glucose and the other organic molecules in food?

Back 19

Enzymes called dehydrogenases remove a pair of hydrogen atoms (2 electrons and 2 protons) from the substrate, thereby oxidizing it. The enzyme delivers the 2 electrons along with 1 proton to its coenzyme, NAD+. The other proton is released as a hydrogen ion (H+) into the surrounding solution.

H-C-OH + NAD+ ----Dehydrogenase---> C = O + NADH + H+

Front 20

The most versatile electron acceptor in cellular respiration

Back 20

NAD+

Front 21

Electron Transport Chain

Back 21

Consists of a number of molecules, mostly proteins, built into the inner membrane of the mitochondria of eukaryotic cells.

Front 22

Is electron transfer from NADH to oxygen an exergonic or endergonic reaction?

Back 22

Exergonic (free energy change of -53 kcal/mol)

Front 23

During cellular respiration, most electrons travel what route?

Back 23

Glucose -> NADH -> Electron Transport Chain-> Oxygen

Front 24

Three stages of cellular respiration?

Back 24

Glycolysis

Pyruvate Oxidation and the Citric Acid Cycle

Oxydative Phosphorylation : electron transport and chemiosmosis

Front 25

Substrate level phosphorylation

Back 25

ATP synthesis that occurs when an enzyme transfers a phosphate group from a substrate molecule to ADP, rather than adding an inorganic phosphate to ADP as in oxidative phosphorylation

Front 26

Glycolysis

(a) Phases

(b) Occurs where?

(c) Starting products

(d) End products

Back 26

(a) Energy invesment phase, Energy payoff phase

(b) Cytosol

(c) Glucose, 2 ATP, (2 NAD+) + (4 E-) + (4 H+)

(d) 2 pyruvate, 2 H2O, 2 ATP (4 formed - 2 used), 2 NADH + 2 H+

Front 27

How many steps are involved in the glycolytic pathway?

Back 27

10

Front 28

What is pyruvate converted to upon entering the mitochondrion?

Back 28

Acetyl coenzyme A (acetyl CoA)

Front 29

Pyruvate oxidation

Back 29

Carried out by a multienzyme complex that catalyzes three reactions:

1. Pyruvate's carboxyl group (--COO-), which is already fully oxidized and thus has little chemical energy, is removed and given off as a molecule of CO2. This is the first step in which CO2 is released during respiration.

2. The remaining two-carbon fragment is oxidized, forming acetate (CH3COO-, which is the ionized form of acetic acid). The extracted electrons are transferred to NAD+, storing energy in the form of NADH.

3. Finally, coenzyme A (CoA), a sulfur-containing compound derived from a B vitamin, is attached via its sulfur atom to the acetate, forming acetyl CoA, which has a high potential energy; in other words, the reaction of acetyl CoA to yield lower-energy products is highly exergonic

Front 30

Prosthetic groups

Back 30

Nonprotein components essential for the catalytic functions of certain enzymes.

Front 31

Citric Acid Cycle

(a) 2 other names

(b) Occurs where?

(c) Starting products

(d) Ending products

Back 31

(a) Krebs Cycle, tricarboxylic acid cycle

(b) Mitochondrion

(c) 2 Pyruvate

(d) 4 CO2, 6 NADH, 2 FADH2, 2 ATP (per glucose, half all numbers per pyruvate)

Front 32

What makes the citric acid cycle a cycle?

Back 32

The regeneration of oxaloacetate

Front 33

How many steps are involved in the citric acid cycle

Back 33

8

Front 34

What is the only member of the electron transport chain that is not a protein?

Back 34

Ubiquinone (coenzyme Q -CoQ)

Front 35

Cytochromes have what prosthetic group?

Back 35

heme (contains iron)

Front 36

What electron transporters (and prosthetic group) comprise the electron transport chain?

Back 36

NADH + 2 e-

Flavoprotein (flavin mononucleotide)

(FADH2 + e- can start the chain here instead of NADH above)

Iron-sulfer protein

Ubiquinone

Cytochromes (heme)

Oxygen

Water

Front 37

NADH donates how many electrons for oxygen reduction?

FADH donates how many electrons for oxygen reduction?

Which electron donor provides less energy for ATP synthesis?

Back 37

2

2

FADH (about 1/3 less energy)

Front 38

Smallest molecular rotary motor known in nature?

Back 38

ATP synthase

Front 39

How does the mitochondrion couple electron transport and energy release to ATP synthesis?

Back 39

Chemiosmosis

Front 40

ATP synthase

Back 40

the enzyme that makes ATP from ADP and inorganic phosphate

Front 41

The power source for ATP synthase

Back 41

A difference in the concentration of H+ on opposite sides of the inner mitochondrial membrane.

Front 42

Chemiosmosis

Back 42

Energy stored in the form of a hydrogen ion gradient across a membrane is used to drive cellular work such as synthesis of ATP (flow of H+ across a membrane).

In general terms, an energy-coupling mechanism that uses energy stored in the form of an H+ gradient across a membrane to drive cellular work.

Front 43

Proton-motive force

Back 43

The H+ gradient that results from the spatial arrangement of electron carriers in such a way that H+ is accepted from the mitochondrial matrix and deposited in the intermembrane space.

Front 44

During respiration, most energy flows in this sequence?

Back 44

glucose

NADH

electron transport chain

proton-motive force

ATP

Front 45

Each NADH that transfers a pair of electrons from glucose to the electron transport chain contributes enough to the proton-motive force to generate how much ATP?

Back 45

Max 3 ATP

Front 46

How much H+ must reenter the mitochondrial matrix via ATP synthase to generate 1 ATP?

Back 46

4 H+

Front 47

How much ATp can a single molecule of NADH generate?

Back 47

2.5

Front 48

1 FADH can generate how much ATP?

Back 48

1.5

Front 49

3 factors that make ATP production unpredictable (variable)?

Back 49

1. Phosphorylation and the redox reaction are not directly coupled to each other, so the ratio of the number of NADH molecules to the number of ATp molecules is not a whole number

2. The ATp yield varies slightly depending on the type of shuttle used to transport electrons from the cytosol into the mitochondrion

3. The variability of the use of the proton-motive force generated by the redox reactions of respiration to drive other kinds of work

Front 50

Oxidative phosphorylation yields about how much ATP?

Back 50

About 26 or 28 ATP

Front 51

Total ATP yield of cellular respiration?

Back 51

About 30 or 32 ATP

Front 52

Total output of cellular respiration?

Back 52

Front 53

Oxidative Phosphorylation

(a) Occurs where

(b) Starting products

(c) Ending Products

Back 53

(a) Mitochondrion (membrane)

(b) All end products of other cellular respiration (6-8 NADH, 2-4 FADH2)

(c) 26 or 28 ATP (+4 from other sites)