Log in
HomeClass Notes1,200,000CA670,000

BIOCH200 Lecture 1: Oxidative phosphorylation: The electron transport chain

81 views4 pages
skycaribou653
9 Dec 2017
School
University of Alberta
Department
Biochemistry
Course
BIOCH200
Professor
Jonathan Parrish

For unlimited access to Class Notes, a Class+ subscription is required.

Document Summary

A brief review of catabolic reactions: breakdown of larger molecules, release of energy as high energy molecules: ato and reduced co-factors (nadh, fadh2, metabolites are oxidised and co-factors are reduced, re-oxidation of co-factors generates atp. Oxidative phosphorylation occurs in the inner mitochondrial membrane. The diagram below summarizes the process of oxidative phosphorylation: Oxidative phosphorylation can be divided into two sections: oxidation of reduced co-factors: 4h+ +4e +o2 2h2o: phosphorylation of adp to atp. Components of the electron transport chain: co-enzyme q (lipid soluble, cytochrome c (peripheral membrane protein) Electrons move from co-factors with lower reduction potential to higher reduction potential: flavin mononucleotide (prosthetic group): fmn +2h+ +2e fmnh2. It has the same structure as fad but has no adenosine. Iron sulphur clusters (prosthetic group): f3+ +e fe2: cytochrome c heme group (prosthetic group): fe3+ +e fe2, co-enzyme q (lipid soluble): transports electrons from complex i and ii to complex iii. Q+ 2h+ +2e qh2 (ubiquinone to ubiquitol)

Get access

Grade+
$40 USD/m
Billed monthly
Grade+
Homework Help
Study Guides
Textbook Solutions
Class Notes
Textbook Notes
Booster Class
10 Verified Answers
Class+
$30 USD/m
Billed monthly
Class+
Homework Help
Study Guides
Textbook Solutions
Class Notes
Textbook Notes
Booster Class
7 Verified Answers

Related Documents

BIOCH200 Lecture Notes - Adipose Tissue, Oxidative Phosphorylation, Uncoupling Protein
bronzesalmon403
BIOCH200 Lecture Notes - Lecture 15: Glycogen, Hepatocyte, Light-Independent Reactions
turquoisewalrus441
BIOCH200
Final Exam
Study Guide
BIOCH200 Study Guide - Glycolysis, Pyruvic Acid, Metabolic Pathway
rosecaribou640

Related Questions

1.

Why does an electron have lower potential energy in an H-O bondthan in an O=O bond?

H has a higher electronegativity than O.

O=O is not stable.

O=O contains a double bond.

The electrons are closer to the oxygen atom in the H-O bond.

None of the answers are correct.

2.

How is the energy from the electron transport chain used mostdirectly?

to form the bonds of a water molecule

to pump hydrogen ions across the mitochondrial inner membraneinto the mitochondrial intermembrane space

to join ADP with a phosphate

to decompose glucose into pyruvate

to rotate ATP synthase

3.

Which process provides the energy needed to pump protons acrossthe mitochondrial membrane during oxidative phosphorylation?

the transfer of electrons in redox reactions

the breakdown of ATP to ADP

the rotation of the ATP synthase rotor

oxidation of isocitrate

None of the answers are correct.

4.

What causes the ATP synthase rotor to spin?

the passing of electrons through ATP synthase

the movement of protons across the mitochondrial membrane

the movement of electrons across the mitochondrial membrane

the synthesis of ATP from ADP and a phosphate group

None of the answers are correct.

5.

What of the following generates the proton-motive force duringoxidative phosphorylation?

buildup of NADH molecules at protein complex I

movement of H+ ions across the mitochondrial membraneduring electron transport

rotation of the ATP synthase rotor

joining of H+ ions with oxygen to form water

None of the answers are correct.

6.

Suppose a microorganism invades a cell, causing damage to ATPsynthase. How would cellular respiration be affected?

Electrons could not be passed down the electron transportchain.

ADP could not be joined with a phosphate to form ATP.

Hydrogen ions could not be pumped into the mitochondrialintermembrane space.

The cell could not release any energy from the glucosemolecule.

Glucose could not be broken down into pyruvate.

7.

Which molecules transport electrons from the citric acid cycleto the electron transport chain?

NADH and FADH2

ATP and ADP

GTP and GDP

oxaloacetate and citric acid

None of the answers are correct.

8.

Which type of reactions control the energy release from glucoseduring the citric acid cycle?

acid-base reactions

redox reactions

random reactions

All answers are correct.

None of the answers are correct.

9.

What is the role of NAD+ in cellular respiration?

to receive electrons from the citric acid cycle and deliver themto the electron transport chain

to catalyze the synthesis of ATP from ADP

to accumulate in the mitochondrial intermembrane space tofacilitate ATP synthesis

to serve as a substrate to bind to acetyl-CoA at the beginningof the citric acid cycle

None of the answers are correct.

10.

Which molecule enters the citric acid cycle?

glucose

pyruvate

ATP

acetyl-CoA

None of the answers are correct.


For each question,choose the ONE BEST And Give Best Explanation [No Explanation nopoints :( ]


1. Metabolismis

A. the means by whichDNA is stored.

B. the sum of all theanabolic and catabolic reactions in a cell.

C. the reactions thatbreak fuel molecules down to gain energy.

D. the reactions thatsynthesise molecules in the cell.

E. the sum of all thereactions taking place in the mitochondrial matrix.


2. The Krebscycle

A. breaks downpyruvate.

B. oxidizes two-carbonunits to produce carbon dioxide and reduced coenzymes.

C. oxidizesglycerol.

D. drives H+ out of themitochondrial matrix.

E. uses GTP rather thanATP to supply phosphate groups.


3. Which of thefollowing statements about the glycolysis pathway in the cytosol isincorrect?

A. It makes ATP.

B. It makesacetyl-CoA.

C. It interacts with thepentose phosphate pathway.

D. All but three stepsare reversible and therefore also operate in gluconeogenesis.

E. It is oxidative underaerobic conditions.


4. %u03B2oxidation

A. breaks the%u03B2-glycosidic bonds in cellulose.

B. uses acetyl-CoA,NADH, and FADH2 to produce long-chain fatty acids.

C. generates pentosesugars.

D. oxidizes fatty acidsto give acetyl-CoA, NADH, and FADH2.

E. Is part oftriacylglycerol biosynthesis.


5.Gluconeogenesis is not capable of making glucose from

A. alanine.

B. lactate.

C. glycerol.

D. palmitate.

E. 2-oxoglutarate.


6. Which of thefollowing statements is incorrect concerning photosynthesis ingreen

plants?

A. It generates ATP,NADPH, and oxygen.

B. It adds carbondioxide to a five-carbon sugar that is then cleaved to form twomolecules of

phosphoglycerate.

C. Its enzymes are foundin the mitochondria.

D. It uses light energyto drive the splitting of water.

E. Its enzymes are foundin the chloroplasts.


7. Positivefeedback is operating

A. when adenosinemonophosphate activates phosphofructokinase.

B. when cAMP activatestranscription of the lac operon.

C. when tryptophaninhibits transcription of the trp operon.

D. whenN-acyl-HSL promotes transcription of the luxoperon.

E. in all the examplesabove.


8. ATP

A. is converted to ADPas H+ enters the mitochondrial matrix.

B. is a coenzyme.

C. passes through theouter mitochondrial membrane by simple diffusion.

D. cannot be made in theabsence of oxygen.

E. concentrations fall to a low levelin resting cells.


1. C6H12O6 + 6O2 Ã 6CO2 + 6H2O Glucose is being _____ to _____ and oxygen is being _____ to _____. a. oxidized; carbon dioxide; reduced; water b. oxidized; water; reduced; carbon dioxide Incorrect c. reduced; water; oxidized; carbon dioxide d. reduced; carbon dioxide; oxidized; water

2. Which of the following stages in the breakdown of the piece of toast you had for breakfast generates the most ATP? a. the citric acid cycle Incorrect b. glycolysis c. the digestion of starch to glucose d. oxidative phosphorylation

3. Which of the following is a catabolic pathway? a. gluconeogenesis b. production of starch Incorrect c. glycolysis d. production of glycogen

4. Per molecule, the oxidation of a fatty acid results in _____ energy storage than the oxidation of glucose. a. the same b. less Incorrect c. more d. None of the above; fatty acids cannot be oxidized.

5. Of the eight reactions in the citric acid cycle, how many are oxidation-reduction reactions? a. one b. two c. three d. four e. five

6. The process of glycolysis transfers the energy in sugar molecules into the stored energy of activated carriers such as ATP and NADH. Which statement is true about glycolysis? a. Only eukaryotic organisms do glycolysis. b. The ten reactions of glycolysis are identical in all eukaryotic cells, but are different in prokaryotic cells due to their diverse metabolic strategies. Incorrect c. The ten reactions of glycolysis are identical in almost all living organisms on the planet. d. There are many ways to oxidize glucose and transfer energy into activated carriers; the diversity of organisms on the planet is reflected in the diversity of their mechanisms of glycolysis.

7. Referring to the sentence completed in #13 above, the purpose of the latter reaction (in active muscle cells) is to _____. a. accumulate lactic acid in the cell, which provides additional energy for the production of ATP Incorrect b. slow down glycolysis until oxygen becomes available again c. accelerate the Krebs cycle, which will restore the oxygen supply d. regenerate NAD+ so that glycolysis can continue in the absence of oxygen

8. What are the products of the citric acid cycle? a. carbon dioxide, NADH, FADH2 and GTP b. carbon dioxide, NAD+, FAD and GTP c. NADH, FADH2, and acetyl CoA Incorrect d. carbon dioxide and water

9. Which statement is true about enzymes? a. Enzymes catalyze chemical reactions because they make inherently endergonic reactions exergonic. b. Each enzyme in a cell can catalyze many different chemical reactions involving chemically different substrates. Incorrect c. Enzymes can only catalyze reactions in one direction. d. After catalyzing a reaction, an enzyme is permanently altered and can no longer bind substrate. e. None of the above is true. 1

10. ∆G measures the change in free energy in a system as it converts reactant (Y) into product (X). When [X] = [Y], ∆G is equal to _____. a. RT b. ΔG° + RT c. ΔG° d. ln [X]/[Y]

11. The ∆G° for the hydrolysis of ATP is -7.3 kcal/mol. What conditions in the cell would lead to a ∆G for ATP hydrolysis of -11 kcal/mol? a. An increase in the ATP/ADP ratio b. An increase in anabolic activity in the cell c. Transport of ATP out of the compartment where the reaction is occurring Incorrect d. A decrease in the ATP/ADP ratio

12. In the first reaction of glycolysis, a phosphate transferred from ATP to a glucose molecule to produce glucose-6-phosphate and ADP. Under conditions existing in the cell, the free energy change for this reaction is -8.0 kcal/mole. Which of the following statements is true? Recall that the ∆G° for the hydrolysis of ATP is -7.3 kcal/mol. a. Glucose concentrations in the cell are always low, making this reaction more favorable than would be expected. b. This reaction is less favorable than would be expected, given the ∆G° of ATP hydrolysis. c. Glucose-6-P concentrations in the cell are very low relative to glucose concentrations, making the reaction more favorable than would be expected. d. The ∆G° for the addition of a phosphate to glucose must be -0.7 kcal/mole.

13. Protein E can bind to two different proteins, S and I. The binding reactions are described by the following equations and values: E + S --> ES Keq for ES = 10 E + I> EI Keq for EI = 2 Given the equilibrium constant values, which one of the following statements is true? a. When S is present in excess, no I molecules will bind to E. b. E binds I more tightly than S. c. The binding energy of the ES interaction is greater than that of the EI interaction. d. Changing an amino acid on the binding surface of I from a basic amino acid to an acidic one will probably make the free energy of association with E more negative.