Energy Transformation

Question 1

What is fermentation

Answer 1

A catabolic pathway of partial degradation for organic fuels in the absence of O2

Question 2

What is aerobic respiration

Answer 2

Catabolic pathway that consumes O2 as a reactant along with organic fuel

Question 3

What is anaerobic respiration

Answer 3

Respiration without O2

Question 4

What is oxidation

Answer 4

The loss of an electron/H+ from a substance in a reaction

Question 5

What is reduction

Answer 5

Addition of an electron/H+ to a substance in a reaction

Question 6

What is a reducing agent

Answer 6

Electron donor

Question 7

What is an oxidizing agent

Answer 7

Electron acceptor

Question 8

Redox reactions that move closer to O2 release or gain energy

Answer 8

Release energy

Question 9

When electrons are stripped from glucose, they are first passed to NAD+ forming NADH. What type of molecule are electron carriers

Answer 9

Coenzyme

Question 10

What is dehydrogenase

Answer 10

An enzyme that can remove a pair of atoms (2e- & 2H+) and delivers them to NAD+

Question 11

What is substrate-level phosphorylation

Answer 11

Formation of ATP during glycolysis and the Krebs cycle

Question 12

How does the production of ATP during substrate-level phosphorylation differ than that produced during oxidative phosphorylation

Answer 12

An enzyme transfers a phosphate group from a substrate to ADP rather than using an inorganic phosphate in the surroundings

Question 13

What happens during the energy investment phase of glycolysis

Answer 13

The cell spends 2 ATP as Ea to begin glycolysis

Question 14

What happens during the energy payoff phase of glycolysis

Answer 14

4 ATP are produced by substrate-level phosphorylation
NAD+ is reduced to NADH

Question 15

What is the net yield of ATP H2O, pyruvate, CO2, NADH, and FADH2 during glycolysis

Answer 15

2 ATP
2 H2O
2 pyruvate
2 NADH
0 FADH2
0 CO2

Question 16

What are the 4 steps of the link reaction

Answer 16

1. Pyruvate enters mitochondria via active transport
2. Pyruvate’s carboxyl group is fully oxidized and given off as 1 CO2
3. Remaining 2-C fragment is oxidized and e- transfers to NAD+, forming NADH
4. CoA S atom attaches to the 2-C, forming Acetyl CoA

Question 17

What is the Krebs cycle

Answer 17

Oxidization of pyruvate

Question 18

What are the first steps of the citric acid cycle

Answer 18

Acetyl CoA adds the acetyl group to oxaloacetate, forming citrate which has high Ep. CoA-SH leaves.

Question 19

What is the net yield of ATP, FADH2, NADH, & CO2 of glycolysis and the Krebs cycle

Answer 19

4 ATP
2 FADH2
10 NADH
4 CO2

Question 20

What is a prosthetic group

Answer 20

Non-protein component (coenzyme/cofactor) bound to proteins in electron transport chain

Question 21

Where is the ETC found

Answer 21

In the inner mitochondria membrane

Question 22

What is the first step in the ETC

Answer 22

Electrons from NADH (2) are first transported to mc in complex 1 (FMN)

Question 23

In which complex does FADH2 transport its electrons and why

Answer 23

Complex 2 because it has lower Ep than NADH

Question 24

What is a cytochrome

Answer 24

Electron carrier in the 3rd and 4th complex (starts with “cyt”)

Question 25

Describe the ETC in terms of electronegativity

Answer 25

Electrons from NADH and FADH2 move from less electronegative carriers to more electronegative carriers, releasing G

Question 26

How does ATP synthase generate ATP

Answer 26

1. H+ ions flow through stator from intermembrane space and then enter a binding site on rotor
2. This binding causes shape change and rotation of rotor. Each H+ makes 1 full rotation before passing through second stator channel and entering matrix
3. Rotor spinning causes rod spinning, which activates catalytic sites in the knob that produce ATP from ADP and Pi

Question 27

How many H+ are transported from the mitochondria matrix to the intermembrane space for each NADH & FADH2

Answer 27

NADH = 3
FADH2 = 2

Question 28

What are 3 reasons the calculated number of ATP may differ from the total produced

Answer 28

1. Phosphorylation/redox reactions may not be coupled properly
2. e- may accidentally be transferred to FAD rather than NAD+
3. Proton-motive force E may be used to drive other cell work rather than be used to produce ATP

Question 29

What is the proton-motive force

Answer 29

H+ gradient between mitochondria membrane with the capacity for the gradient perform work

Question 30

What is the difference between anaerobic respiration and fermentation

Answer 30

Anaerobic respiration uses an ETC, just with a different final electron receptor. Fermentation occurs without O2

Question 31

By what method does fermentation produce ATP

Answer 31

Substrate-level phosphorylation

Question 32

What are the 2 parts to fermentation

Answer 32

1. Glycolysis
2. NAD+ regeneration

Question 33

What are the 2 steps to alcohol fermentation

Answer 33

1. CO2 is released from pyruvate and pyruvate becomes acetaldehyde
2. Acetaldehyde is reduced by NADH to ethanol, regenerating NAD+

Question 34

What is the 1 step in lactic acid fermentation

Answer 34

Pyruvate is reduced by NADH to form lactate, regenerating NAD+ (no CO2)

Question 35

What is an obligate anaerobe

Answer 35

Organism that does only fermentation and cannot survive in O2 rich environment

Question 36

What is a falcultative anaerobe

Answer 36

Organism that can survive on fermentation or respiration
Eg. Muscle cells

Question 37

For proteins to be used as fuel, they must first be digested into their

Answer 37

Amino acids

Question 38

True or false: amino acid must be in excess to be used as fuel

Answer 38

True

Question 39

Before amino acids can be used as fuel which group must be removed: carboxyl or amine

Answer 39

Amine group

Question 40

What is beta oxidation
(Fats can become fuel through this process)

Answer 40

The breakdown of a fatty acid down to 2-C fragments that can be joined by a CoA to form acetyl CoA