CHM 425 Chapter 14

The adenine nucleotide translocase (ADP-ATP translocase), a transporter located in the inner mitochondrial membrane, transports ADP and ATP across the membrane. It is an antiporter. (Recall that these adenine nucleotides are negatively charged: ADP3- and ATP4-.) Answer parts (a), (b), and (c), below. What is the ratio of ADP to ATP transported by the adenine nucleotide translocase? That is, how many ADP are transported for each ATP transported? -3 ADP: 4 ATP -2 ADP: 3 ATP -4 ADP: 3 ATP -1 ADP: 1 ATP

-1 ADP: 1 ATP

The electron transport chain (ETC), or respiratory chain, is linked to proton movement and ATP synthesis. Select the statements that accurately describe the electron transport chain. Choose all that apply. -Electron transfer in the ETC is coupled to proton transfer from the matrix to the intermembrane space. -Prosthetic groups, such as iron-sulfur centers, are directly involved with electron transfer. -Electrons generated by the citric acid cycle in the intermembrane space enter the ETC. -The reactions of the ETC take place in the outer membrane of mitochondria. - The outer membrane of mitochondria is readily permeable to small molecules and hydrogen ions. -Electron carriers are organized into four complexes of proteins and prosthetic groups. -Electron carriers in the ETC include ubiquinone (coenzyme Q) and cytochrome c.

-Electron transfer in the ETC is coupled to proton transfer from the matrix to the intermembrane space. -Prosthetic groups, such as iron-sulfur centers, are directly involved with electron transfer. - The outer membrane of mitochondria is readily permeable to small molecules and hydrogen ions. -Electron carriers are organized into four complexes of proteins and prosthetic groups. -Electron carriers in the ETC include ubiquinone (coenzyme Q) and cytochrome c.

The adenine nucleotide translocase (ADP-ATP translocase), a transporter located in the inner mitochondrial membrane, transports ADP and ATP across the membrane. It is an antiporter. (Recall that these adenine nucleotides are negatively charged: ADP3- and ATP4-.) Answer parts (a), (b), and (c), below. Which direction is ADP3- transported during times of active oxidative phosphorylation? -there is no net flow of ADP3- -into the mitochondrial matrix -out of the mitochondrial matrix

-into the mitochondrial matrix

identify the statements that accurately describe how hydrogen ion concentration relates to energy production in oxidative phosphorylation -oxidative phosphorylation relies on the hydrogen ion concentration gradient generated and maintained by the electron transport chain -the Ph in the mitochonndrial matrix is lower than the pH in the intermembrane space -hydrogen ions are actively transported out of the mitochondrial matrix - ATP synthase provides energy in the form of ATP to actively transport H+ into the mitochondrial matrix -Energy is generated as a result of the difference in hydrogen ion concentration between the intermembrane space and the cytoplasm -hydrogen ion concentration is higher in the intermembrane space than in the mitochondrial matrix

-oxidative phosphorylation relies on the hydrogen ion concentration gradient generated and maintained by the electron transport chain -hydrogen ions are actively transported out of the mitochondrial matrix -hydrogen ion concentration is higher in the intermembrane space than in the mitochondrial matrix

The adenine nucleotide translocase (ADP-ATP translocase), a transporter located in the inner mitochondrial membrane, transports ADP and ATP across the membrane. It is an antiporter. (Recall that these adenine nucleotides are negatively charged: ADP3- and ATP4-.) Answer parts (a), (b), and (c), below. What drives the transport of adenine nucleotides? -transport is coupled with ATP hydrolysis -the electrochemical gradient (membrane potential) -simple diffusion

-the electrochemical gradient (membrane potential)

A mitochondrial membrane complex consisting of ATP synthase, adenine nucleotide translocase (ADP-ATP translocase), and phosphate translocase functions in oxidative phosphorylation. Adenine nucleotide translocase, a transporter located in the inner mitochondrial membrane, transports ADP and ATP across the membrane. Phosphate translocase is also located in the inner mitochondrial membrane. It transports H and phosphate (H2PO4-) across the membrane. How many H ions are required to be moved across the membrane for the synthesis of 1 ATP? Include both the H ions needed for ATP synthesis itself and for other transport required for ATP synthesis.

4 H+ ions

Chemiosmotic theory

A proton gradient serves as the energy reservoir that drives ATP formation. The theory explains how the energy of a proton gradient can be used to synthesize ATP. The free energy associated with the protonmotive force is mostly due to the charge differences across the membrane.

The role of electron transport and ATP synthesis is to convert reducing equivalents to

ATP

How many protons are fluxed from the intermembrane space for the sysnthesis of 1 ATP?

Four

Which side has the higher proton concentration, mitochondrial matrix or intermembrane space?

Intermembrane Space

What is the function of adenine nucleotide translocase? Is it symport or an anti-port?

It allows ADP to enter the mitochondria and ATP to exit the mitochondria since the inner mitochondrial membrane is impermeable to charged substances. It is an anti-port.

Between white muscle tissue and red muscle tissue, which one has more mitochondria? Why?

Red has more mitochondira. Because white muscle tissue relies on anaerobic glycolysis for its energy while red muscle tissue must sustain substantial and steady outputs of power and this power requires a large amount of ATP.

What is the function of complex V?

Synthesize ATP from ADP & Pi in a reaction driven by the proton gradient formed during the electron transport.

What are the enzymes in citric acid cycle, electron transport complexes, and ATP synthase located in mitochondrion?

The mitochondrial matrix holds the pyruvate dehydrogenase complex which is embedded in the inner membrane and most of the enzymes that catalyze fatty acid oxidation. The matrix also contains metabolites and inorganic ions and a pool of NAD+ and NADP+ that remains separate from the pyridine nucleotide coenzymes of the cytosol. Mitochondrial DNA and all of the enzymes required for DNA replication, transcription and translation are located in the matrix along with genes that encode electron transport proteins in the mitochondrial DNA.

In euks, what is the cellular location of electron transport chain and ATP synthase complexes?

inner mitochondrial membrane

2,4-dinitrophenol (DNP) was a popular ingredient in diet pills in the 1930s before it was discovered that moderate doses of the compound cause exceptionally high body temperature and even death. Complete the following passages detailing how DNP\'s mechanism of action explains why it causes both high body temperature and weight loss. 2,4-dinitrophenol (DNP) causes _______ to pass directly across the inner mitochondrial membrane instead of returning to the mitochondrial matrix through _________ proteins. Because of DNP's effect on the mitochondrion, less energy is captured in the form of _____ and more energy is instead wasted as heat.

protons; ATP synthase; ATP

What compounds connect TCA cycle with electron transport and ATP synthesis?

reducing equivalents as products of glycolysis and the citric acid cycle since the oxidation of glucose and acetyl CoA is coupled to the reduction of NAD+ and Q. Subsequent oxidation of NADH and QH2 results in passage of electrons through a membrane-associated electron transport system where the energy released can be saved through the phosphorylation of ADP to ATP