Test 3 Sapling Part

Which of the following is the major regulator of oxygen consumption during oxidative phosphorylation?

ADP

ATP synthase, shown in the image, uses the proton (H+) gradient to drive ATP synthesis. Put the steps of ATP synthesis in order from proton transport to the synthesis of ATP.

First step: Protons from the inter membrane space bind to protons binding sites on c subunits As the c ring rotates ... The y subunit rotates along with the c subunit The y subunit rotates and interacts ... Each B subunit binds ADP ... Last step.

Identify the substances that can readily pass through the inner mitochondrial membrane.

H2O CO2 O2

Determine whether each of the concentrations causes an increase or decrease in the activity of the electron transport chain. Increase in activity Decrease in activity

Increase in activity: High ADP concentration, high oxygen concentration Decrease in activity: Low NADH ... Low phosphate ... Large difference in H+ ...

Lipoproteins are globular structures that are responsible for transporting lipids through the blood stream. Two types of lipoproteins are LDL and HDL. Classify each description as applying to LDL, HDL, or both. LDL HDL Both LDL and HDL

LDL: bad cholesterol, increased levels are associated with atherosclerosis, transport cholesterol from liver to other tissues HDL: good cholesterol, transports excess cholesterol to liver Both LDL and HDL: the rest

Lipoproteins are circulating particles required for the transport of triacylglycerols (TAGs) and cholesterol within the body. Based on the functions provided, identify the corresponding lipoprotein and its apoprotein (apolipoprotein) constituents. Note that HDL particles contain two apoproteins.

Lipoprotein: Chylomicron VLDL LDL HDL Apoprotein constituents: ApoB-48 ApoB-100 ApoB-100 ApoA-I & ApoA-II Function: Dietary Endogenous Cholesterol Cholesterol

A nutrition researcher finds that placing young rats on a completely fat-free diet results in abnormal growth, unhealthy skin and fur, and a shortened lifespan. However, if the fat-free diet is supplemented with plant material, then the young rats show none of these symptoms. Which statements explain why plant material prevents the symptoms?

Mammals do not express enzymes that can synthesize linoleate. Linoleate is an essential fatty acid for animals and is commonly found in plant material.

The synthesis of cholesterol is a process that involves over 30 different steps. Which step is the rate-determining step of cholesterol synthesis?

The conversion of HMG-CoA to mevalonate by HMG-CoA reductase.

In what organelle or membrane are triacylglycerols synthesized and fatty acids elongated?

endoplasmic reticulum

The yield of ATP by the mitochondrial ATP synthase can be estimated by the number of protons pumped out of the matrix during the oxidation of NADH and FADH2 , and the number of protons moved into the matrix as ATP is formed. Mitochondrial oxidation of NADH by O2 results in the transport of ten protons from the matrix to the intermembrane space, while oxidation of FADH2 results in the transport of six protons. ATP synthase utilizes three protons from the intermembrane space to form one ATP . Use the information given above to make the following calculations. Note: Recent data on ATP synthase suggests that the number of protons required per ATP varies with the number of 𝑐subunits. Here, an approximate value of 3 protons/ATP is used. How many ATP are formed per NADH oxidized? How many ATP are formed per FADH2 oxidized? The ATP yields calculated above do not consider other mitochondrial components that affect the proton gradient during ATP synthesis. When these other components are considered, the number of ATP produced per FADH2 oxidized is lowered to 1.5 . Choose the statements that correctly describe the reason for the lower yield of ATP.

1- 3.33 2- 2 3- Four H+ move into the matrix for each ATP formed. Three H+ are utilized by ATP synthase directly and an additional H+ is utilized during transport of the substrates H2PO−4 , ADP , and product, ATP . The number of H+ that move into the matrix during ATP synthesis has increased by one H+/ATP . Therefore, the calculation of ATP yield changes from 6/3=2.0 to 6/4=1.5 for FADH2 .

Complete the sentences to correctly describe steps in fatty acid synthesis. Some terms will not be used, and some will be used more than once. Fatty acid synthesis begins with a preparatory step in which is transferred from to the . However, it cannot pass through the membrane, so it is transported as , which is cleaved to and . In the cytosol, acetyl‑CoA is converted to , a three‑carbon compound. Fatty acid synthesis begins with the transfer of the acetyl group from acetyl‑CoA to fatty acid synthase. ‑carbon groups, supplied by , are added to the growing acyl chain in a series of steps involving condensation,, and dehydration reactions. Elongation of the fatty acid chain stops at carbon atoms, after cycles, as the free fatty acid is released. citrate mitochondria cytoplasm acetyl‑CoA oxaloacetate Two malonyl‑CoA reduction 16 7 malonyl‑CoA acetyl‑CoA Answer Bank Three 14 oxidation acetyl‑CoA malonyl‑CoA malonyl‑ACP

1- Acetyl-CoA 2- Mitochondria 3- Cytoplasm 4- Citrate 5- Acetyl-CoA 6- OAA 7- Malonyl-CoA 8- 2 9- Malonyl-CoA 10- reduction 11- 16 12- 7

Which enzyme does lovastatin inhibit? (Hint: Pay special attention to the highlighted portion of the molecule.) The HMG-CoA reductase reaction (the rate-limiting step) is a major feedback control point for cholesterol synthesis. Select the molecules that stimulate the degradation of HMG-CoA reductase enzyme by proteolysis.

1- HMG-CoA reductase 2- dephosphorylated farnesyl pyrophosphate cholesterol mevalonate

In mitochondria, the rate of electron transfer is tightly coupled to the demand for ATP. When the rate of use of ATP is relatively low, the rate of electron transfer is low; when demand for ATP increases, electron‑transfer rate increases. Under these conditions of tight coupling, the number of ATP molecules produced per atom of oxygen consumed when NADH is the electron donor, the P/O ratio, is about 2.5. Predict what would happen when an uncoupling agent, such as 2,4‑dinitrophenol, is added to an actively respiring tissue preparation. The rate of oxygen consumption The rate of ATP synthesis The P/O ratio Ingestion of uncouplers causes profuse sweating and an increase in body temperature. Explain this phenomenon in molecular terms.

1- Increases 2- Decreases 3- Decreases 4- Energy from the increased rate of electron transport is converted to heat rather than to ATP.

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− . Which direction is ADP3− transported during times of active oxidative phosphorylation? What drives the transport of adenine nucleotides? What is the ratio of ADP to ATP transported by the adenine nucleotide translocase, how many ADP are transported for each ATP transported?

1- into the mitochondrial matrix 2- the electrochemical gradient (membrane potential) 3- 1 ADP : 1 ATP

Do fatty acid synthesis and degradation occur in the same location of the cell? Where does fatty acid synthesis occur in the cell?

1- no 2- in the cytoplasm

Identify true statements about the synthesis of various lipids.

Eicosanoids are synthesized in most human tissues. The triacylglycerol biosynthetic pathway provides the precursors for the synthesis of glycerophospholipids. Triacylglycerols are synthesized by adding fatty acid groups to a glycerol backbone. Glycerophospholipids may be synthesized from diacylglycerols.

Without using a textbook, predict the sequence of electron transport carriers (the sequence of participants in the redox reactions) in the electron transport chain. A table of standard reduction potentials is given for reference. OxidantReductant𝐸′0(V)succinate𝛼‑ketoglutarate−0.67NAD+NADH−0.320FADFADH2−0.22CoQ (ubiqinone)CoQH2 (ubiquinol)0.045cytochrome 𝑏 (Fe3+)cytochrome 𝑏 (Fe2+)0.077cytochrome 𝑐 (Fe3+)cytochrome 𝑐 (Fe2+)0.254cytochrome 𝑎 (Fe3+)cytochrome 𝑎 (Fe2+)0.29O2H2O0.8166

Electrons flow from compounds with lower 𝐸′0 to compounds of higher 𝐸′0. The compound with the lowest 𝐸′0 is NAD+ and the compound with the highest 𝐸′0 is O2. The sequence is NAD+⟶ubiquinone⟶cytochrome 𝑏 ⟶cytochrome 𝑐 ⟶cytochrome 𝑎 ⟶O2

Classify each of the phrases as describing exogenous cholesterol transport, endogenous cholesterol transport, or reverse cholesterol transport. Exogenous pathway Endogenous pathway Reverse cholesterol transport

Exogenous pathway: transport of cholesterol from intestine to liver, cholesterol carried by chylomicron, membrane receptors recognize ApoE of chylomicron initiating endocytosis. Endogenous pathway: The rest Reverse cholesterol transport: Cholesterol carried in HDL, pathway requires Sr-Br receptor

Which of these actions regulate oxidative phosphorylation under hypoxic conditions?

pH decreases below 6.5 and IF1 exists as a stable dimer capable of inhibiting the ATPase activity of ATP synthase. The protein inhibitor IF1 binds two ATP synthase molecules and inhibits their ATPase activity. HIF‑1 replaces a subunit of Complex IV of the electron transport chain with a subunit that is more efficient under hypoxic conditions.

Phosphatidate (phosphatidic acid) is a precursor in the synthesis of some lipids. Identify the lipids that have phosphatidate as a precursor.

phosphatidylinositol triacylglycerols glycerophospholipids

The net reaction catalyzed by malate dehydrogenase is malate+NAD+↽−−⇀oxaloacetate+NADH+H+ The standard reduction potentials for the half-reactions are given in the table. OxidantReductant𝐸∘′ (V)oxaloacetate+2H+malate−0.17 NAD++H+NADH−0.32 Calculate Δ𝐸∘′ for the given reaction.

Δ𝐸∘′= -.15 Δ𝐺∘′= 28.95 However, note that one of the half-reactions, and the sign of 𝐸°′, should be reversed. Malate is oxidized in the overall reaction, so reverse that half‑reaction. malate↽−−⇀oxaloacetate+2H++2e−NAD++H++2e−↽−−⇀NADH𝐸∘′=+0.17 V𝐸∘′=−0.32 V To calculate Δ𝐸∘′, add the 𝐸∘′ values for each half‑reaction. malate+NAD+↽−−⇀oxaloacetate+NADH+H+Δ𝐸∘′=(0.17 V)+(−0.32)=−0.15 V To calculate Δ𝐺∘′, use the equation Δ𝐺∘′=−𝑛𝐹Δ𝐸∘′=−2(96.5 kJ⋅mol−1⋅V−1)(−0.15 V)=29 kJ⋅mol−1 where 𝑛 is the number of electrons transferred (in this example, 2 electrons) and 𝐹 is Faraday's constant, 96.5 kJ·mol−1·V−1.

Reactive oxygen species (ROS) are unstable, or reactive, compounds that result from the partial reduction of oxygen. ROS can cause damage to molecules, including membrane lipids and nucleic acids, and may be associated with some diseases. Which of these compounds are reactive oxygen species?

⋅OH ⋅O−2 H2O2

A mitochondrial membrane complex consisting of ATP synthase, adenine nucleotide translocase (ATP-ADP translocase), and phosphate translocase functions in oxidative phosphorylation. Adenine nucleotide translocase, an antiporter located in the inner mitochondrial membrane, moves ADP into and ATP out of the matrix. Phosphate translocase is also located in the inner mitochondrial membrane. It transports H+ ions and phosphate H2PO−4 ions into the matrix. The energy derived from the movement of H+ ions down an electrochemical gradient from the intermembrane space into the matrix is used to drive the synthesis of ATP. How many H+ ions must be moved into the matrix for the synthesis of 1 ATP?

4

Consider the figure. Order the steps of ATP synthesis by ATP synthase. Only three sentences are accurate; four are inaccurate. O is the open site, L is the loose site, and T is the tight site. ADP and Pi are in the surrounding medium

ADP and Pi bind to the L site the B subunit converts from the L to the T conformation, ATP is synthesized from ADP and Pi the B subunit is converted from the T to the O conformation; ATP is released

The given statements concern the relationship between mitochondrial hydrogen ion concentration and energy storage as ATP during oxidative phosphorylation. Classify each statement as either accurate or inaccurate. Accurate statements Inaccurate statements

Accurate statements: higher in the intermembrane space than it is in the mitochondrial matrix, H+ ions cannot freely pass through the inner mitochondrial membrane, H+ move through a channel formed by ATP synthase releasing energy from ATP Inaccurate statements: the rest of them

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.

Electron carriers are organized into four complexes of proteins and prosthetic groups. Prosthetic groups, such as iron-sulfur centers, are directly involved with electron transfer. The reactions of the ETC take place in the inner membrane of mitochondria. Electrons generated by the citric acid cycle in the mitochondrial matrix enter the ETC. Electron transfer in the ETC is coupled to proton transfer from the matrix to the intermembrane space.

Classify the phrases as pertaining to fatty acid synthesis or fatty acid oxidation. Fatty acid synthesis Fatty acid oxidation

Fatty acid synthesis: the rest of the stuff Fatty acid oxidation: Acetyl-CoA is a product takes place in the mitochondria intermediate linked to coenzyme A uses FAD and NAD+

Lipogenesis, or fatty acid synthesis, occurs in several cycles. A diagram of the reactions of the first cycle of fatty acid synthesis is shown. Select all of the true statements.

In lipogenesis, acetyl and acyl molecules are activated by an acyl carrier protein (ACP). Malonyl‑CoA adds a two‑carbon group to the growing fatty acid chain with each cycle. Acetyl‑SCoA provides the carbon used for fatty acid synthesis. The reactions of lipogenesis include, but are not limited to, two reductions and a dehydration.

A young rat maintained on a diet deficient in methionine fails to thrive unless choline is included in the diet. Choose the best explanation.

Methionine is required for phosphatidylcholine synthesis from phosphatidylethanolamine, but phosphatidylcholine can also be made from choline by a salvage pathway.

Select all of the true statements regarding non‑shivering thermogenesis.

Norepinephrine stimulates the hydrolysis of fatty acids, which activate the uncoupler protein. Thermogenin decreases the proton gradient by enabling protons to reenter the mitochondrial matrix without taking part in ATP synthesis. ATP synthase can be bypassed in brown adipocytes. Non‑shivering thermogenesis takes place in brown adipose tissue.

The standard free energy change for a reaction can be calculated using the equation Δ𝐺∘′=−𝑛𝐹Δ𝐸∘′ where 𝑛 is the number of electrons transferred, 𝐹 is Faraday's constant, 96.5 kJ·mol−1·V−1, and Δ𝐸∘′ is the difference in reduction potential. For each of the given reactions, determine the number of electrons transferred (𝑛) and calculate standard free energy (Δ𝐺∘′) . Consider the half-reactions and overall reaction for reaction 1. half-reactions:fumarate2−+2H+CoQH2↽−−⇀succinate2−↽−−⇀CoQ+2H+ overall reaction:fumarate2−+CoQH2↽−−⇀succinate2−+CoQΔ𝐸∘′=−0.009 V 𝑛= Δ𝐺∘′=kJ⋅mol−1 Consider the half-reactions and overall reaction for reaction 2. half-reactions:cytochrome 𝑐1(Fe2+)cytochrome 𝑐 (Fe3+)↽−−⇀cytochrome 𝑐1(Fe3+)↽−−⇀cytochrome 𝑐 (Fe2+) overall reaction:cyt 𝑐1(Fe2+)+cyt 𝑐 (Fe3+)↽−−⇀cyt 𝑐1(Fe3+)+cyt 𝑐 (Fe2+)Δ𝐸∘′=0.034 V

𝑛=2 Δ𝐺∘′=1.737 kJ⋅mol−1 n=1 Δ𝐺∘′= -3.281 Δ𝐺∘′=−2(96.5 kJ⋅mol−1⋅V−1)(−0.009 V)=1.74 kJ/mol

Identify the biochemical pathways that occur in the mitochondria.

𝛽-oxidation oxidative phosphorylation citric acid cycle

Complete the given reaction which is part of the electron transport chain. The abbreviation Q represents coenzyme Q. Use this abbreviation for the product. The reactant that is reduced is In complex III, electrons are transferred from coenzyme Q to cytochrome 𝑐 , which contains iron. QH2+2cyt 𝑐(Fe3+)⟶Q+2cyt 𝑐(Fe𝑥)+2H+ Determine the oxidation number for iron on the right side of the reaction arrow.

1- NADH+H++Q⟶NAD++QH2 2- Q 3- 2

After digestion of a large carbohydrate meal, monosaccharides that exceed caloric requirements are diverted into the synthesis of fatty acids and triacylglycerol. Fatty acid synthesis consumes acetyl‑CoA, ATP, and NADPH. These three compounds can be made from glucose at the same time that glucose is being processed for fatty acid synthesis. Complete the statements by moving terms to the appropriate blanks.

1- glycolysis 2- pentose phosphate 3- oxidative decarboxylation 4- acetyl-CoA 5- TCA 6- NADH and FADH2 7- ATP 8- oxidative phosphorylation 9- acetyl group shuttle 10- fatty acid synthesis 11- NADPH 12- Oxidative phase 13- pentose phosphate 14- malic enzyme

Reactive oxygen species (ROS) are unstable oxygen‑containing molecules that can cause damage to enzymes and membranes. Cells can defend against damage by converting these ROS to harmless species. Complete the reactions. What is the enzyme or enzyme type that catalyzes this reaction? What is the enzyme or enzyme type that catalyzes this reaction?

reaction: 2O⋅−2+2H+⟶H2O2+O2 superoxide mutase reaction: H2O2+2GSH⟶2H2O+GS−SG glutathione peroxidase

The complete oxidation of one glucose molecule yields 30 or more ATP . Glucose catabolism includes glycolysis, pyruvate oxidation, and the citric acid cycle. The total yield of ATP includes ATP , GTP , and reduced cofactors that yield ATP from the electron transport chain and oxidative phosphorylation. Which processes yield the most ATP ? When determining the ATP yield for each process, include ATP derived from reduced cofactors.

citric acid cycle

The synthesis of phosphatidylcholine has alternate pathways. In mammals, for example, phosphatidylcholine (PC) can be synthesized by two pathways: a pathway that begins with choline and a pathway that includes phosphatidylethanolamine. Classify each description as pertaining to PC synthesis from choline or from phosphatidylethanolamine. Choline pathway Phosphatidylethanolamine pathway

Choline pathway: predominant pathway in mammalian cells pathway requires phosphorylation and subsequent activation by CTP pathway involves 1,2-diacylglycerol Phosphatidylethanolamine pathway the rest of the stuff

The citric acid cycle occurs in the The electron transport chain is located in the Oxidative phosphorylation takes place in the

mitochondrial matrix. the inner membrane of the mitochondrion. the inner membrane of the mitochondrion.

Which of these are components of animal fatty acid synthase (FAS)?

3-hydroxyacyl dehydratase enoyl reductase β-ketoacyl reductase acetyl transacylase

A diagram of the reactions of the first round of fatty acid synthesis (lipogenesis) is shown. How many cycles of the synthesis pathway are needed to produce myristic acid, C13H27COOH?

6

The percent composition by mass is given for each of several plasma lipoproteins. ChylomicronVLDLLDLHDLTotal lipids98917846Triacylglycerols865563Phospholipids7202226Cholesterol2782Cholesterol esters3124215Proteins262254 Note that this table is simplified and the values can vary. The numbers given are within the ranges generally reported. Which lipoprotein is the most soluble? Which lipoprotein is the least dense?

1- HDL 2- chylomicron

One process catalyzed by NADH dehydrogenase is NADH+H++ubiquinone↽−−⇀NAD++ubiquinol The standard reduction potentials for the half‑reactions are given in the table. OxidantReductant𝐸′0ubiquinone+2H++2e−ubiquinol0.045NAD++H++2e−NADH-0.32 Calculate Δ𝐸′0 for the reaction as shown.

Answer: Δ𝐸′0= .365V Calculate Δ𝐺′0 .Δ𝐺′0=- 70.44kJ/mol How to do it: Δ𝐸′0=(0.045 V)+(0.32)=0.365 V Δ𝐺′0=−𝑛𝐹Δ𝐸′0 Δ𝐺′0=−2(96.5kJmol⋅V)(0.365 V)

Chylomicrons, VLDL, and LDL transport triacylglycerols (TAGs) and cholesterol in the blood. All three of these lipoproteins contain an apoC‑II component. Identify one reason this is significant.

ApoC‑II activates lipoprotein lipase.

Identify the statements that accurately describe how hydrogen ion concentration relates to energy production in oxidative phosphorylation.

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

Phosphate translocase is also located in the inner mitochondrial membrane. It transports H+ and phosphate (H2PO−4) across the membrane. It is a symporter. Which direction is ATP4− transported during times of active oxidative phosphorylation? What drives the transport of adenine nucleotides? 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? What drives the transport of H2PO−4 across the membrane? Which direction is it transported during oxidative phosphorylation?

1- out of the mitochondrial matrix 2- the electrochemical gradient (membrane potential) 3- 1 ADP:1 ATP 4- H+ and H2PO−4 are transported into the matrix in a process driven by the proton gradient.

Label the structures on the given mitochondrion. Then, determine the direction of ATP, phosphate (Pi) , and passive hydrogen ion (H+) transport across the inner membrane by transport proteins.

1- outer membrane 2- cristae 3- inter membrane 4- H 5- Pi 6- ATP 7- Matrix

When considering free energy change, biochemists define a biochemical standard state, ΔG∘′, which differs from the chemical standard state, ΔG∘ . A similar distinction must be made with reduction potentials. In contrast to the chemical reduction potential, Δ𝐸∘ , the biochemical standard reduction potential, Δ𝐸∘′ Why might the standard reduction potential for a reaction differ from the reduction potential found in a cell?

1- specifies a pH of seven. 2- Concentrations in the cell might not be 1 M .

Glycolysis produces NADH . However, NADH cannot cross the inner mitochondrial membrane to be used in the electron transport chain (respiratory chain). The malate-aspartate shuttle in some animal cells transfers electrons from cytosolic NADH to the matrix. How is oxaloacetate modified to a form that can be transported out of the matrix? Which compound is transported across the inner membrane in exchange for malate?

1- transamination 2- α‑ketoglutarate

The reduced coenzymes generated by the citric acid cycle donate electrons in a series of reactions called the electron transport chain. The energy from the electron transport chain is used for oxidative phosphorylation. Which compounds donate electrons to the electron transport chain? Which compound is the final electron acceptor? Which compounds are the final products of the electron transport chain and oxidative phosphorylation?

1-FADH2, NADH 2- O2 3- NAD+, H2O, ATP, FAD

Malonyl-CoA is an intermediate in fatty acid synthesis. It also regulates fatty acid metabolism. Which of the molecules regulate the enzyme that catalyzes malonyl‑CoA synthesis? Which of the enzymes does malonyl‑CoA regulate? Determine how each of the choices affects fatty acid synthesis and β‑oxidation. inhibits fatty acid synthes isinhibits β‑oxidation

1-citrate fatty acids or fatty acyl-CoA 2- carnitine acyltransferase 3- inhibits fatty acid synthesis high concentration of fatty acids in the cytosol inhibits β‑oxidation high concentration of malonyl-CoA

Cholesterol synthesis occurs in several stages. Place the molecules in the order they appear in cholesterol synthesis. Although only one arrow is shown between each of the molecules, there are actually multiple steps represented by each arrow.

Acetate Mevalonate Activate isoprene squalene cholesterol

Lipids are transported in the blood in complexes with proteins. These water‑soluble complexes are called lipoproteins. Complete the sentences by selecting the lipoprotein that transports each lipid.

Chylomicrons transport dietary lipids from the small intestine. VLDLs transport triacylglcerols (triglycerides) from the liver to fat storage cells. LDLs transport cholesterol from the liver to tissues for membrane synthesis. HDLs transport cholesterol from cells to the liver.

Select the true statements about the electron transport chain.

Coenzyme Q and cytochrome 𝑐 are components of the electron transport chain. The products of the electron transport chain are H2O and either NAD+ or FAD. In the electron transport chain, a series of reactions moves electrons through carriers.

Determine which complex of the electron transport chain (respiratory chain) each phrase describes.

Complex I: Electron transfer from NADH to ubiquinone (coenzyme Q), NADH dehydrogenase complex. Complex II: Electron transfer from succinate to ubiquinone, Succinate dehydrogenase complex Complex III: electron transfers from ubiquinol to cytochrome c, cytochrome bc1 complex. Complex IV: Electron transfer from cytochrome c to O2, cytochrome oxidase

Although some citric acid cycle enzymes operate primarily in the mitochondria, malate dehydrogenase operates in both the cytosol and the mitochondria. Match each function to cytosolic malate dehydrogenase or mitochondrial malate dehydrogenase. Cytosolic malate dehydrogenase Mitochondrial malate dehydrogenase

Cytosolic malate dehydrogenase: Reduces OAA to Malate, Oxidazes NADH produced in glycolysis to NAD+, transfers reducing equivalents from cytosolic NADH to a molecule that can traverse the inner mitochondrial membrane. Mitochondrial malate dehydrogenase: the rest of the others

The acetyl group of acetyl‑CoA, produced by oxidative decarboxylation of pyruvate in the mitochondrion, is transferred to the cytosol by the acetyl group shuttle. Similarly, the acyl group shuttle (the carnitine shuttle) transfers the fatty acyl group from the cytosol to the mitochondrion in preparation for β oxidation. Select the statements that describe the similarities or differences between the acetyl group shuttle and the acyl group shuttle.

The acetyl-group shuttle generates NADPH, whereas the acyl group shuttle does not. Both the fatty acyl group and the acetyl group cross the mitochondrial membrane after conjugation to another molecule. Both the acyl group shuttle and the acetyl group shuttle keep the mitochondrial and the cytosolic pools of CoA separate.