Szweda Flashcards

Why is the conversion of ADP to ATP energetically unfavorable?

If the product of a reaction is of lower free energy than the reactant, the reaction is ________

If the product of a reaction is of higher free energy than the reactant, the reaction is ________

Enzymes catalyze reactions (speed and specificity) by lowering the energy required to reach the ______ _______ of a reaction

Where is the energy for the production of ATP primarily derived from?

Conversion of sugars, fatty acids, and amino acids to _____ represents the full oxidation of carbon sources.

Muscle likes _____
Liver likes ______

What are some common reducing agents?

What are some common oxidizing agents?

The energetically favorable oxidation of carbon sources is coupled to the energetically unfavorable reduction of NAD⁺ and FAD⁺ to _______ and ______, which act as mobile electron carriers.

The net oxidation of glucose (via glycolysis in the cytosol and Krebs cycle in the mitochondria) coupled with reduction of O₂ (via the ETC in the mitochondrial inner membrane) results in the production of ____ molecules of ATP

What is the carbon carrier from glycolysis to the Krebs cycle, or from the cytosol to the mitochondria?

For the Krebs cycle to maintain activity, acetyl CoA must be supplied. This is accomplished primarily within the mitochondrial matrix through the conversion of ________ (derived from glycolysis in the cytosol) and __________ (beta-oxidation) to acetyl CoA

Within the Krebs cycle, the two carbons of acetyl CoA are converted to two molecules of ______ .

What is the terminal electron acceptor in the electron transport chain?

As electrons pass through the electron transport chain, they lose electrochemical potential and the energy is utilized to pump protons from the matrix space into the inner mitochondrial space, thus creating the proton gradient for what two things?

The ETC starts with ______ energy NADH and moves to the _______ energy reaction of reducing O₂ to H₂O

NADH donates electrons to which complex in the ETC?

FADH₂ donates electrons to which complex in the ETC?

ATP is synthesized through the action of what enzyme? Where does this enyzme reside, and where does it derive its energy for the production of ATP from?

This refers to O₂ consumption when only Krebs cycle intermediates are supplied

Why does oxygen consumption increase when ADP is added to state 2 respiration? What is this called?

Why does the rate of O₂ consumption slow upon conversion of ADP to into ATP? What is this called

The rate of which respiration state provides an overall indication of ATP synthase, electron transport, and Krebs cycle function?

This state of respiration provides an index of membrane integrity and the rate at which protons leak from the inner mitochondrial membrane space to the matrix in the absence of ATP production

A high rate of this respiration state could indicate that the membrane has been damaged or, as is the case in adipose tissue, protons are transported via uncoupling proteins in an effort to produce heat

What is the ratio of state 3:state 4 respiration referred to as? What does this indicate when it is high? What does it indicate when it is low coupled with a high state 4 respiration rate (and what is it referred to as)?

What does a high ADP/O ratio (ADP consumed relative to oxygen utilization) indicate?

Conversion of pyruvate, derived from glycolysis in the cytosol, to acetly CoA, for utilization by the Krebs cycle, is catalyzed by what multienzyme complex, which is within the mitochondrial matrix?

What is the E1 co-enzyme of pyruvate dehydrogenase?

What is the prosthetic group for E2 (Dihydrolipoyl transacetylase)?

Pyruvate dehydrogenase is a mulienzyme complex. What is E1 classified as?

Pyruvate dehydrogenase is a multienzyme complex. What is E2 classified as?

Pyruvate dehydrogenase is a multienzyme complex. What is E3 classified as?

What are two co-enzymes associated with the E3 enzyme dihydrolipoyl dehydrogenase (of pyruvate dehydrogenase)?

By what two methods is pyruvate dehydrogenase regulated?

____ activates (turns on) pyruvate dehydrogenase by activating phosphatase to dephosphorylate the complex

The Krebs cycle is composed of how many enzymes?

What enzyme catalyzes the formation of Citrate from Acetyl CoA + Oxaloacetate in the Krebs cycle? Is this reaction thermodynamically favorable?

Within the Krebs cycle, what enzyme catalyzes the conversion of Citrate to Isocitrate? Is this reaction thermodynamically favorable?

Are thermodynamically favorable reactions highly regulated, or unregulated?

Within the Krebs cycle, what enzyme catalyzes the conversion of Isocitrate to alpha-ketoglutarate? Is this reaction thermodynamically favorable?

Within the Krebs cycle, what enzyme catalyzes the conversion of alpha-Ketoglutarate to Succinyl CoA? Is this reaction thermodynamically favorable?

Within the Krebs cycle, what enzyme catalyzes the conversion of Succinyl CoA to Succinate? What is unique about this step?

Within the Krebs cycle, what enzyme catalyzes the conversion of Succinate to Fumarate? What is unique about this step?

Within the Krebs cycle, what enzyme catalyzes the conversion of Fumarate to _L- Malate?

Within the Krebs cycle, what enzyme catalyzes the conversion of _L- Malate to Oxaloacetate? Is this reaction thermodynamically favorable?

The enzyme responsible for converting _L- Malate to Oxaloacetate (Malate Dehydrogenase) is highly endergonic, and thermodynamically unfavorable. How is this chemical reaction driven to completion?

What are the four regulation steps of the Krebs cycle?

What is the major regulator of the Krebs cycle?

Protons are pumped from the matrix to the intermembrane space at which complexes in the ETC?

What co-enzyme serves as the carrier of electrons to complex III?

What is responsible for electron transfer from complexes III to IV?

What is the complex I inhibitor, and where does this occur?

What is the complex III inhibitor, and where does this occur?

What are the complex IV inhibitors, and where do they inhibit?

When electron flow is blocked, all upstream redox centers should be in the _______ state while downstream of the inhibition components should be ________.

Another pathway by which electrons are transferred to the ETC is when the first enzyme in beta-oxidation, ____________, transfers electrons (reduces) to the electron transfer flavoprotein (ETF). The ETF then reduces ETF:Q oxidoreductase which subsequently transfers electrons to coenzyme Q.

_________ formed in the cytosol during glycolysis can also pass electrons directly to coenzyme Q (into the ETC) via the action of ____________.

ATP synthase has numerous subunits that make up two domains, the F₀ and F₁ domains. The F₀ domain is submerged in the lipid bilayer while the F₁ domain protrudes into the mitochondrial matrix. Which domain is the site of ATP synthesis?

Uncoupling agents act by carrying electrons from the intermembrane space to the matrix, thus collapsing the proton gradient. What is an example of an uncoupling agent?

Uncoupling agents in the mitochondria _____ O₂ consumption and ______ ATP synthesis. What is this termed?

Where are uncoupling proteins particularly abundant, which serves to utilize electron transport to generate heat.

What are the four regulators of Oxidative Phosphorylation?

Ischemia leads to ____ O₂, ____ ATP, _____ pH, and ____ Ca²⁺. This in turn leads to reprefusion, with ____ free radical generation, which then leads to alterations in mitochondrial function.

What are two reasons that pH drops in ischemia?

When oxygen is limited (such as during strenuous exercise or ischemia) and electron transport activity cannot be maintained, pyruvate is converted to ________ within the cytosol by the enzyme _________ _________.

When the rate of electron transport through the ETC is reduced due to diminished requirements for ATP or when components of the chain are inhibited, the half-life of reduced components of the chain increases as does the likelihood that electrons will interact with O₂ resulting in the incomplete reduction of O₂ to ________ _______.

Superoxide anion can be converted to hydrogen peroxide through the action of what enzyme? Metal ions can subsequently be oxidized by _______ ______ resulting in the production of hydroxyl radical. These free radical species and pro-oxidants are highly reactive and can cause damage to lipid, protein, DNA, and RNA

Within the mitochondria, what two Krebs cycle enzymes are particularly sensitive to oxidative modification? These have been reported to decline in function during numerous neurodegenerative, neuromuscular, and cardiovascular diseases.

What enzyme is a key regulatory site within the Krebs cycle?