SCT I - Electron Transport Chain

Question 1

Name Complex I and its function

Answer 1

Complex I: NADH Dehydrogenase

• Pumps out H+ from Matrix to IMS
• Sends electrons to Ubiquinone

Question 2

Name Complex II and its function

Answer 2

Complex II: Succinate Dehydrogenase

• Sends electrons to Ubiquinone

Question 3

Name Complex III and its function

Answer 3

Complex III: Ubiquinone-Cytochrome C Oxidoreductase

• Receives potential energy from Ubiquinol
• Pumps out H+ from Matrix to IMS
• Sends electrons to Cytochrome C

Question 4

Name Complex IV and its function

Answer 4

Complex IV: Cytochrome Oxidase

• Pumps out H+ from Matrix to IMS
• Sends electrons to Cytochrome C

Question 5

What’s the role of Ubiquinone?

Answer 5

Converts itself to Ubiquinol after receiving electrons from Complexes I and II and gives the electrons to Complex III granting it potential energy to push out protons

Question 6

What’s the role of Cytochrome C?

Answer 6

Hogs electrons given by Complexes III and IV

Question 7

What’s the role of ATP Synthase?

Answer 7

Uses the chemiosmotic gradient of the protons in the IMS to produce ATP through allowing the protons back into the matrix

Question 8

What happens to the electrons that are accumulated at Complex IV?

Answer 8

Electrons are given to oxygen (final electron acceptor) which is converted to water

Question 9

Name the inhibitor of Complex I

Answer 9

Rotenone

Question 10

Name the inhibitor of Complex II

Answer 10

Malonate

Question 11

Name the inhibitor of Complex III

Answer 11

Antimycin A

Question 12

Name the inhibitor of Complex IV

Answer 12

CO & Cyanide