Exam II-L8 (TCA/Ox Phos)

Question 1

Utilization of oxygen during energy production will produce more ___, especially over long periods of physical exertion

Answer 1

ATP

Question 2

Where does aerobic metabolism occur?

Answer 2

Mitochondria

Question 3

True or False: The TCA cycle, ETC, and Ox Phosph take places in mitochondria

Answer 3

True

Question 4

___: the space within the inner membrane

___: highly selective, acts as barrier to most molecules

___: contains channels that allow for exchange of molecules with cytosol

Answer 4

Mitochondrial Matrix
Inner Membrane
Outer Membrane

Question 5

Pyruvate must be transported into the mitochondria for ___ to occur

Answer 5

aerobic metabolism

Question 6

What type of transporter allows pyruvate to enter into the mitochondrial matrix?

Answer 6

Pyruvate transporter

Question 7

What is the main function of the PDH Complex?

Answer 7

To convert pyruvate to acetyl CoA

Question 8

____: a large aggregate of many enzymes and co-factors located within the mitochondria

Answer 8

PDH Complex

Question 9

Conversion of pyruvate to acetyl CoA can only take place within the ___

Answer 9

mitochondria

Question 10

How many molecules of NADH are produced in reactions of the PDH complex? How any molecules are lost as CO2?

Answer 10

1 NADH
1 CO2

Question 11

True or False: When pyruvate is converted into Acetyl CoA, it is being decarboxylated

Answer 11

True

Question 12

Which reaction is the key, irreversible step of aerobic metabolism of glucose?

Answer 12

Pyruvate to Acetyl CoA

Question 13

True or False: Acetyl CoA and NADH will lead to production of ATP

Answer 13

True

Question 14

Pyruvate entering the mitochondria activates the _______

Answer 14

PDH complex (via: substrate level activation of enzyme activity)

Question 15

How does accumulation of ATP, acetyl CoA, and NADH levels affect the PDH complex activity?

Answer 15

Accumulation of ATP, Acetyl CoA, and NADH levels decrease PDH complex activity (feedback inhibition)

Question 16

What type of poisoning directly inhibits the PDH complex?

Answer 16

Arsening poisoning

Question 17

What types of nutrients are required for the PDH complex to function?

Answer 17

-B1 and B5
-Micronutrients

Question 18

What are four clinical symptoms associated with conditions that affect the PDH complex (e.g nutritional deficiencies, genetic mutations, arsenic poisoning)?

Answer 18

1) Confusion
2) Difficulty breathing
3) Problems with muscle contractions
4) Lactic acidosis

Question 19

If the PDH complex is mutated or has defects, one can develop clinical symptoms due to reduced ___ metabolism, which leads to decrease energy production

Answer 19

aerobic metabolism

Question 20

What is the first step of the TCA Cycle?

Answer 20

Oxaloacetate combines with Acetyl CoA to create citrate

Question 21

What is the fuel for the TCA Cycle?

Answer 21

Acetyl CoA

Question 22

In the last phase of the TCA cycle, ___ is regenerated, which allows cycle to continue if there is more Acetyl-CoA available

Answer 22

Oxaloacetate

Question 23

How many carbons leave the TCA Cycle as CO2?

Answer 23

2 carbons

Question 24

2 carbons enter the TCA Cycle in the form of ____ (2 carbon molecule)

Answer 24

Acetyl CoA

Question 25

What allows the TCA cycle to function as a true cycle?

Answer 25

There is no net gain or loss of carbons

Question 26

How many NADH, FADH2, and GTP are produced in the TCA cycle?

Answer 26

3 NADH made 1 FADH2 made 1 GTP made

Question 27

Under anaerobic conditions, NADH in the ___ is reoxidized by __

Answer 27

cytosol; LDH

Question 28

Under aerobic conditions, NADH in the cytosol is re-oxidized to NAD+ and excess electrons are ____________

Answer 28

donated to the mitochondria for use in ETC

Question 29

___ and ____ will donate their electrons to the ETC

Answer 29

NADH and FADH2 will donate their electrons to the ETC

Question 30

Where are Complex I, II, III, and IV, as well as CoQ and Cytochrome C located within the mitochondria? A. Outer mitochondrial membrane B. Inner mitochondrial membrane C. Mitochondrial matrix

Answer 30

B. Inner mitochondrial membrane

Question 31

Which of the ETC complexes/molecules has the strongest and weakest reduction potential?

Answer 31

strongest reduction potential = O2 weakest reduction potential = Complex I

Question 32

Complex I accepts electrons from ___

Answer 32

NADH

Question 33

Complex I passes electrons to ___, causing 4 protons to be pumped into the intermembrane space

Answer 33

Complex I passes electrons to CoQ, causing 4 protons to be pumped into the intermembrane space

Question 34

True or False: Both Complex I Complex II pass electrons to CoQ

Answer 34

True

Question 35

Complex II accepts electrons from ____

Answer 35

FADH2

Question 36

Complex III accepts electrons from ___

Answer 36

CoQ

Question 37

CoQ will accept electrons from ___ or ___ and pass them to Complex III

Answer 37

CoQ will accept electrons from Complex I (NADH) or Complex II (FADH2) and pass them to Complex III

Question 38

Complex III passes electrons to ____ and causes _ protons to be pumped through Complex III

Answer 38

Cytochrome C; 4 protons

Question 39

Cytochrome C passes electrons to Complex __

Answer 39

Complex IV

Question 40

Electrons flow from Complex IV to ___, forming water. This causes Complex IV to pump __ H+ into the intermembrane space.

Answer 40

O2; two

Question 41

What is the final electron acceptor in the ETC?

Answer 41

Oxygen - without oxygen, ETC is inhibited

Question 42

___ and ___ inhibit complex IV

Answer 42

CO and CN-

Question 43

True or False: CN- and CO cause protons to not be pumped into the intermembrane space and cause NADH and FADH2 to not be oxidized

Answer 43

True

Question 44

True or False: Lactic acidosis can arise due to CN- or CO exposure/poisoning

Answer 44

True

Question 45

Flow of electrons (donated by NADH) across the ETC creates an electric current that powers complexes __, ___, and ___ to translocate protons into the intermembrane space

Answer 45

Flow of electrons (donated by NADH) across the ETC creates an electric current that powers complexes I, III, and IV to translocate protons into the intermembrane space

Question 46

True or False: FADH2 causes less protons to be pumped into the intermembrane space, because Complex I is not utilized

Answer 46

True

Question 47

As electron transport activity continues, protons build up in the intermembrane space, creating a ___ and __ gradient

Answer 47

pH and electric gradient

Question 48

True or False: Build up of protons in the intermembrane space creates potential energy

Answer 48

True

Question 49

When protons are allowed to flow back into the mitochondrial matrix, this creates a usable energy known as the _____ to drive ATP synthesis

Answer 49

proton motive force

Question 50

____: the channel that allows flow of protons ____: binds ADP and phosphate

Answer 50

F0 subunit: the channel that allows flow of protons F1 subunit: binds ADP and phosphate

Question 51

The flow of protons through the ___ subunit of ATP Synthase leads to rotation, causing production of ATP in the __ subunit

Answer 51

F0 subunit; F1 subunit

Question 52

While anerobic metabolism yields approx ____ net ATP, aerobic metabolism yields ___

Answer 52

2 ATP 30-32 ATP

Question 53

True or False: Defects in mitochondrial function lead to insufficient ATP production, creating problems throughout the body

Answer 53

True

Question 54

Mutations found in components of aerobic metabolism affect __ production

Answer 54

ATP

Question 55

True or False: Mitochondrial diseases can cause lactic acidosis

Answer 55

True

Question 56

Which tissues and organs are most affected by lack of ATP?

Answer 56

Nervous System Muscle

Question 57

Lack of neuronal function exacerbates ___ complications

Answer 57

muscular

Question 58

Clinical features of mitochondrial disease?

Answer 58

1) exertional fatigue 2) lactic acidosis 3) increased risk of muscle damage 4) opthalmoplegia (weakening of eye muscles) 4) ptsosis (eyelids)