Lecture 9

Question 1

Once pyruvate is produced, where is it transported?

Answer 1

Mitochondrion

Question 2

The Krebs cycle is part of…

Answer 2

Substrate level phosphorylation

Question 3

What is the first step of the oxidation of pyruvate?

Answer 3

Decarboxylation: COO- group forms CO2

Question 4

The oxidation of pyruvate is carried out by…

Answer 4

pyruvate dehydrogenase enzyme complex

Question 5

What is the second step of the oxidation of pyruvate?

Answer 5

reduction: NAD+ —> NADH

Question 6

What is the third step?

Answer 6

the remaining acetyl group is transferred to the molecule coenzyme A

Question 7

Through which bond is the acetyl group transferred to the coenzyme A?

Answer 7

acetyl thioester bond

Question 8

Energy is required for the third step, where does it come from?

Answer 8

the redox reaction in the second step

Question 9

What does the oxidation of pyruvate yields?

Answer 9

1 co2, 1 NADH, 1 acetyl CoA molecule

Question 10

Where does the Krebs cycle takes place?

Answer 10

mitochondrial matrix

Question 11

Step 1 of Krebs cycle…

Answer 11

Condensation: oxaloacetate + acetyl group form citrate

Question 12

Step 2-3 of Krebs cycle…

Answer 12

Isomerization: citrate is transformed into isocitrate by removing and adding water

Question 13

step 4 of Krebs cycle…

Answer 13

first oxidation: NAD+&raquo_space;> NADH

Question 14

Step 5 of Krebs cycle…

Answer 14

second oxidation NAD+&raquo_space;> NADH

Question 15

Step 6 of Krebs cycle…

Answer 15

substrate level phosphorylation: GTP can transfer a phosphate to ADP

Question 16

Step 7 of Krebs…

Answer 16

Third oxidation FAD&raquo_space;> FADH2

Question 17

What does the Krebs cycle yields?

Answer 17

1 ATP, 2 CO2, 3 NADH, 1 FADH2

Question 18

What is yield for 1 glucose?

Answer 18

2 FADH2, 10 NADH, 4 ATP BUT 30 ATP AFTER CHEMIOSMOSIS

Question 19

What is chemiosmosis?

Answer 19

The energy released by the transport allows for the formation of ATP from ADP and inorganic phosphate