Exam II-L8 (TCA/Ox Phos) Flashcards
Utilization of oxygen during energy production will produce more ___, especially over long periods of physical exertion
ATP
Where does aerobic metabolism occur?
Mitochondria
True or False: The TCA cycle, ETC, and Ox Phosph take places in mitochondria
True
___: the space within the inner membrane
___: highly selective, acts as barrier to most molecules
___: contains channels that allow for exchange of molecules with cytosol
Mitochondrial Matrix
Inner Membrane
Outer Membrane
Pyruvate must be transported into the mitochondria for ___ to occur
aerobic metabolism
What type of transporter allows pyruvate to enter into the mitochondrial matrix?
Pyruvate transporter
What is the main function of the PDH Complex?
To convert pyruvate to acetyl CoA
____: a large aggregate of many enzymes and co-factors located within the mitochondria
PDH Complex
Conversion of pyruvate to acetyl CoA can only take place within the ___
mitochondria
How many molecules of NADH are produced in reactions of the PDH complex? How any molecules are lost as CO2?
1 NADH
1 CO2
True or False: When pyruvate is converted into Acetyl CoA, it is being decarboxylated
True
Which reaction is the key, irreversible step of aerobic metabolism of glucose?
Pyruvate to Acetyl CoA
True or False: Acetyl CoA and NADH will lead to production of ATP
True
Pyruvate entering the mitochondria activates the _______
PDH complex (via: substrate level activation of enzyme activity)
How does accumulation of ATP, acetyl CoA, and NADH levels affect the PDH complex activity?
Accumulation of ATP, Acetyl CoA, and NADH levels decrease PDH complex activity (feedback inhibition)
What type of poisoning directly inhibits the PDH complex?
Arsening poisoning
What types of nutrients are required for the PDH complex to function?
-B1 and B5
-Micronutrients
What are four clinical symptoms associated with conditions that affect the PDH complex (e.g nutritional deficiencies, genetic mutations, arsenic poisoning)?
1) Confusion
2) Difficulty breathing
3) Problems with muscle contractions
4) Lactic acidosis
If the PDH complex is mutated or has defects, one can develop clinical symptoms due to reduced ___ metabolism, which leads to decrease energy production
aerobic metabolism
What is the first step of the TCA Cycle?
Oxaloacetate combines with Acetyl CoA to create citrate
What is the fuel for the TCA Cycle?
Acetyl CoA
In the last phase of the TCA cycle, ___ is regenerated, which allows cycle to continue if there is more Acetyl-CoA available
Oxaloacetate
How many carbons leave the TCA Cycle as CO2?
2 carbons
2 carbons enter the TCA Cycle in the form of ____ (2 carbon molecule)
Acetyl CoA
What allows the TCA cycle to function as a true cycle?
There is no net gain or loss of carbons
How many NADH, FADH2, and GTP
are produced in the TCA cycle?
3 NADH made
1 FADH2 made
1 GTP made
Under anaerobic conditions, NADH in the ___ is reoxidized by __
cytosol; LDH
Under aerobic conditions, NADH in the cytosol is re-oxidized to NAD+ and excess electrons are ____________
donated to the mitochondria for use in ETC
___ and ____ will donate their electrons to the ETC
NADH and FADH2 will donate their electrons to the ETC
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
B. Inner mitochondrial membrane
Which of the ETC complexes/molecules has the strongest and weakest reduction potential?
strongest reduction potential = O2
weakest reduction potential = Complex I
Complex I accepts electrons from ___
NADH
Complex I passes electrons to ___, causing 4 protons to be pumped into the intermembrane space
Complex I passes electrons to CoQ, causing 4 protons to be pumped into the intermembrane space
True or False: Both Complex I Complex II pass electrons to CoQ
True
Complex II accepts electrons from ____
FADH2
Complex III accepts electrons from ___
CoQ
CoQ will accept electrons from ___ or ___ and pass them to Complex III
CoQ will accept electrons from Complex I (NADH) or Complex II (FADH2) and pass them to Complex III
Complex III passes electrons to ____ and causes _ protons to be pumped through Complex III
Cytochrome C; 4 protons
Cytochrome C passes electrons to Complex __
Complex IV
Electrons flow from Complex IV to ___, forming water. This causes Complex IV to pump __ H+ into the intermembrane space.
O2; two
What is the final electron acceptor in the ETC?
Oxygen
- without oxygen, ETC is inhibited
___ and ___ inhibit complex IV
CO and CN-
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
True
True or False: Lactic acidosis can arise due to CN- or CO exposure/poisoning
True
Flow of electrons (donated by NADH) across the ETC creates an electric current that powers complexes __, ___, and ___ to translocate protons into the intermembrane space
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
True or False: FADH2 causes less protons to be pumped into the intermembrane space, because Complex I is not utilized
True
As electron transport activity continues, protons build up in the intermembrane space, creating a ___ and __ gradient
pH and electric gradient
True or False: Build up of protons in the intermembrane space creates potential energy
True
When protons are allowed to flow back into the mitochondrial matrix, this creates a usable energy known as the _____ to drive ATP synthesis
proton motive force
____: the channel that allows flow of protons
____: binds ADP and phosphate
F0 subunit: the channel that allows flow of protons
F1 subunit: binds ADP and phosphate
The flow of protons through the ___ subunit of ATP Synthase leads to rotation, causing production of ATP in the __ subunit
F0 subunit; F1 subunit
While anerobic metabolism yields approx ____ net ATP, aerobic metabolism yields ___
2 ATP
30-32 ATP
True or False: Defects in mitochondrial function lead to insufficient ATP production, creating problems throughout the body
True
Mutations found in components of aerobic metabolism affect __ production
ATP
True or False: Mitochondrial diseases can cause lactic acidosis
True
Which tissues and organs are most affected by lack of ATP?
Nervous System
Muscle
Lack of neuronal function exacerbates ___ complications
muscular
Clinical features of mitochondrial disease?
1) exertional fatigue
2) lactic acidosis
3) increased risk of muscle damage
4) opthalmoplegia (weakening of eye muscles)
4) ptsosis (eyelids)
