Question

Bioinformatics #5

1. According to the KEGG pathway for oxidative phosphorylation, which of the following enzymes do not shuttle protons into the innermembrane space (IMS)?

1.3.5.1

1.3.5.1 and 3.6.3.6

1.6.5.3 and 1.10.2.2

3.6.3.3

2. According to the stoichiometry indicated on the KEGG pathway, ______ matrix protons are consumed and ______ transported to the IMS during the reaction catabolized by Complex I

6;4

4;6

2;6

2;4

3. According to the KEGG pathway and Chapter 15, Complex III transports ____ protons to the IMS per substrate molecule using __ of the Q cycle.

2; both cycles

2; only 1 cycle

4; both cycles

4; only 1 cycle

4. Which of the following statements best describes the oval-shaped arrows involving UQ and UQH2, which are located within the membrane in the colorful KEGG diagram?

The quinone pool remains tightly bound to the membrane surface, where UQ serves as a substrate for Complexes I and II

The quinone pool is loosely bound within the membrane, where UQ serves as the substrate for Complexes I and II

The quinone pool is loosely bound within the membrane, where UQ serves as the substrate for Complex III

The quinone pool is loosely bound within the membrane where UQH2 serves as the substrate for Complexes I and II

5. The KEGG and NCBI databases contain a wealth of information obtained from sequencing and analyzing the complete genome of Acinetobacter baumannii 1656-2, which is a medically important oxidase negative (cytochrome c oxidase- negative) bacterium that is multidrug resistant. For this microorganism, which statement regarding oxidative phosphorylation is correct?

This microbe possesses subunits of cytochrome c oxidase and therefore displays cytochrome c oxidase activity

The formation of ATP depends directly on the oxidation of cytochrome c.

The cytochrome bd complex allows oxygen to be reduced by the quinone pool

Subunit a of the F-type ATPase has 876 amino acids

Bioinformatics #5

1. According to the KEGG pathway for oxidative phosphorylation, which of the following enzymes do not shuttle protons into the innermembrane space (IMS)?

1.3.5.1

1.3.5.1 and 3.6.3.6

1.6.5.3 and 1.10.2.2

3.6.3.3

2. According to the stoichiometry indicated on the KEGG pathway, ______ matrix protons are consumed and ______ transported to the IMS during the reaction catabolized by Complex I

6;4

4;6

2;6

2;4

3. According to the KEGG pathway and Chapter 15, Complex III transports ____ protons to the IMS per substrate molecule using __ of the Q cycle.

2; both cycles

2; only 1 cycle

4; both cycles

4; only 1 cycle

4. Which of the following statements best describes the oval-shaped arrows involving UQ and UQH2, which are located within the membrane in the colorful KEGG diagram?

The quinone pool remains tightly bound to the membrane surface, where UQ serves as a substrate for Complexes I and II

The quinone pool is loosely bound within the membrane, where UQ serves as the substrate for Complexes I and II

The quinone pool is loosely bound within the membrane, where UQ serves as the substrate for Complex III

The quinone pool is loosely bound within the membrane where UQH2 serves as the substrate for Complexes I and II

5. The KEGG and NCBI databases contain a wealth of information obtained from sequencing and analyzing the complete genome of Acinetobacter baumannii 1656-2, which is a medically important oxidase negative (cytochrome c oxidase- negative) bacterium that is multidrug resistant. For this microorganism, which statement regarding oxidative phosphorylation is correct?

This microbe possesses subunits of cytochrome c oxidase and therefore displays cytochrome c oxidase activity

The formation of ATP depends directly on the oxidation of cytochrome c.

The cytochrome bd complex allows oxygen to be reduced by the quinone pool

Subunit a of the F-type ATPase has 876 amino acids

Answer 1

Ans: 3.6.3.3

succinate dehydrogenase- 1.3.5.1

NADH:ubiquinone reductase- 1.6.5.3

proton-translocating ATPase - 3.6.3.6

quinol---cytochrome-c reductase - 1.10.2.2

Cd2+-exporting ATPase - 3.6.3.3

All other enzyme complexes except 3.6.3.3 are involved in oxidative phosphorylation leading to proton translocation to IMS.

2. 6,4

According to KEGG pathway, 6 (2H+ and 4H+) protons are consumed from matrix and 4protons are transported to IMS.

3. Ans: 4, both cycles

KEGG shows that 2 X 2 H+ protons are transported to IMS. 2x represents electorn transfer in 2 cycles inside the cytochrome bc₁ complex.

4. Ans: The quinone pool is loosely bound with the membrane where UQ serves as the substrate for complex III.

the enzyme complexes are connected by 2 mobile redox-active molecules, i.e. a lipophilic quinone, designated CoQ or ubiquinone, embedded in the membrane lipid bilayer, and a hydrophilic heme protein, cytochrome c, localized on the external surface of the inner membrane.

Two electrons are removed from QH₂ at the Q_O site and sequentially transferred to two molecules of cytochrome c in complex III.

5. Ans: cytochrome bd complex allows oxygen to be reduced by quinone pool.

Clinical microbiologists typically differentiate members of the genus Acinetobacter from other Moraxellaceae by performing an oxidase test, as Acinetobacter sp. are the only members of the Moraxellaceae to lack cytochrome c oxidases.