Chapter 9: Cell Respiration and Fermentation

Question 1

Fermentation

Answer 1

catabolic process, partial degeneration of sugars or other organic fuel that occurs without the use of oxygen

Question 2

Aerobic Respiration

Answer 2

oxygen is consumed as a reactant along with organic fuel, most efficient catabolic pathway

Question 3

Cellular Respiration

Answer 3

includes aerobic and anaerobic respiration, food provides fuel and the body processes it to give off CO2, H2O, and energy

Question 4

Anaerobic Respiration

Answer 4

using substances other than oxygen as reactants in a similar process that harvests chemical energy without oxygen

Question 5

Oxidation

Answer 5

loss of electrons, charge goes up

Question 6

Redox Reactions

Answer 6

electrons transfer from one reactant to another, loss of electrons is oxidation, gain of electrons is reduction

Question 7

Reduction

Answer 7

gain of electrons, charge goes down

Question 8

Oxidizing Agent

Answer 8

removes an electron and takes on the negative charge

Question 9

Reducing Agent

Answer 9

reduces a molecule and the molecule accepts the donated electron

Question 10

NAD+

Answer 10

electron acceptor, functions as an oxidating agent during respiration, when enzymes called dehydrogenase remove a pair of hydrogen atoms from the substrate (glucose) it oxidizes the glucose, and then the enzyme takes the 2e- and 1p+ to its coenzyme NAD+ to form NADH, most versatile electron acceptor in cellular respiration

Question 11

Citric Acid Cycle

Answer 11

acetyl CoA enters the cycle, breaks down the glucose into CO2

Question 11

NADH

Answer 11

hydrogen received into the NAD+, each molecule formed during respiration represents stored energy that can be taken to make ATO, reduced form of NAD+

Question 12

Oxidative Phosphorylation

Answer 12

ETC takes electrons from NADH generated in the first two steps, passes electrons down the chain, electrons combine with molecular oxygen and hydrogen ions to form water, energy released in each step is stored in a form that the mitochondrion can use fro making ADP into ATP, oxidative phosphorylation is powered by redox reactions on the ETC

Question 12

Electron Transport Chain

Answer 12

number of molecules, mostly proteins, built into the inner membrane of eukaryotic mitochondria, electrons removed from glucose are taken by NADH into the high energy end of the ETC

Question 13

Electron Downhill Route

Answer 13

glucose —>NADH —> ETC —> oxygen

Question 14

Stages of Cellular Respiration

Answer 14

1. glycolysis
2. pyruvate oxidation and citric acid cycle
3. oxidative phosphorylation

Question 15

Glycolysis

Answer 15

occurs in the cytosol, begins the degeneration process by breaking down glucose into two compounds of a molecule called pyruvate, in eukaryotes the pyruvate goes into the mitochondria and is oxidized into acetyl CoA

Question 16

Chemiosmosis

Answer 16

movement of ions across a semipermeable membrane down their electrochemical gradient, flow of H+ ions, energy coupling method that uses energy stored in the form of an H+ gradient to drive cellular work

Question 17

Substrate Level Phosphorylation

Answer 17

mechanism that forms a small amount of ATP in a few reactions of glycolysis and the krebs cycle, occurs when an enzyme transfers a phosphate group to a substrate molecule to an ADP instead of adding an inorganic phosphate to ADP as in oxidative phosphorylation

Question 18

2 Phases of Glycolysis

Answer 18

1. Energy Investment
2. Energy Payoff

Question 19

Energy Investment

Answer 19

cells spend ATP to generate charge and push things to happen, repaid with interest in phase 2

Question 20

Energy Payoff

Answer 20

ATP is produced by substrate level phosphorylation and NAD+ is reduced to NADH by electrons released from the oxidation of glucose

Question 21

Acetyl CoA

Answer 21

also known as acetyl coenzyme A, links glycolysis and the citric acid cycle. carried out by a multienzyme complex that catalyzes 3 reactions

Question 22

Prosthetic Groups

Answer 22

bound to multiprotein complexes, nonprotein components such as cofactors and coenzymes essential for the catalytic functions of certain enzymes

Question 23

Flavoprotein

Answer 23

has a prosthetic molecule called flavin mononucleotide, returns to its oxidized from as it passes electrons to iron-sulfur proteins

Question 24

Ubiquinone

Answer 24

small electron carrier, hydrophobic, only member of the ETC that is not a protein

Question 25

Cytochromes

Answer 25

electron carrier between oxygen and ubiquinone, prosthetic group (heme group) has an iron atom that accepts and donates electrons

Question 26

ATP Synthase

Answer 26

multisubunit complex with 4 main parts, each made up of multiple polypeptides, smallest molecular rotary

Question 26

FADH2

Answer 26

other reduced product of the citric acid cycle, adds its electrons from complex III at a lower energy level than NADH

Question 27

H+ Gradient

Answer 27

high H+ ion concentration in the intermembrane space, sends H+ ions to ATP synthase to perform chemiosmosis and go back into the mitochondrial matrix, passage of H+ through ATP synthase uses exergonic flow to drive the phosphorylation of ADP

Question 28

Proton-Motive Force

Answer 28

H+ gradient that comes as a result of the H+ arrangement in the inner mitochondrial matrix and deposited into the intermembrane space, emphasizes the capacity of the gradient to perform work

Question 29

Sequence of Most Energy Flow

Answer 29

glucose —> NADH —> ETC —> proton motive force —> ATP

Question 30

3 Main Metabolic Processes

Answer 30

glycolysis, pyruvate oxidation and Krebs cycle, and electron transport chain

Question 31

Alcoholic Fermentation

Answer 31

pyruvate is converted into ethanol in 2 steps
1. release CO2 from pyruvate, which is converted to the 2 carbon compound acetaldehyde
2. acetaldehyde is reduced by NADH into ethanol, thus regenerating NAD+ for glycolysis to continue

Question 32

2 Types of Skeletal Muscle Fibers

Answer 32

red and white

Question 32

Lactic Acid Fermentation

Answer 32

pyruvate is reduced directly into lactate by NADH, regenerates NAD+ with no CO2 release

Question 33

Red Muscle

Answer 33

oxidizes glucose fully to CO2

Question 34

Obligate Anaerobes

Answer 34

organisms that carry out only fermentation and respiration, cannot survive in the presence of oxygen

Question 34

White Muscle

Answer 34

provides significant amounts of lactate from the pyruvate made during glycolysis, fast but energetically inefficient ATP production

Question 35

Facultative Anaerobes

Answer 35

species of organisms, yeast and bacteria, can make enough ATP to survive using either fermentation or respiration

Question 36

Deamination

Answer 36

process in which amino groups are removed from proteins so that they can be fed into glycolysis or Krebs cycle

Question 37

Beta Oxidation

Answer 37

breaks fatty acids down into 2 carbon fragments that enter the citric acid cycle as acetyl CoA, also produces NADH and FADH2

Question 38

Substrate Level Phosphorylation

Answer 38

addition of a phosphate when energy is coming from a substrate of glucose, highly inefficient in making ATP

Question 38

Energy Flow

Answer 38

redox reactions, OIL RIG (oxidation is loss, reduction is gain)

Question 39

2 Types of Phosphorylation

Answer 39

substrate level and oxidative

Question 40

Phosphorylation

Answer 40

the addition of a phosphate group to a molecule

Question 41

Oxidative Level Phosphorylation

Answer 41

uses NADH and FADH2 to build a high concentration gradient that will produce a lot of ATP efficiently