Lab 6

Question 1

Pyruvate

Answer 1

Question 2

Lactate

Answer 2

Question 3

Acetyl-CoA

Answer 3

Question 4

Oxaloacetate

Answer 4

Question 5

Citrate

Answer 5

Question 6

Alpha-ketoglutarate

Answer 6

Question 7

Succinate

Answer 7

Question 8

Fumarate

Answer 8

Question 9

Malate

Answer 9

Question 10

Hypoxanthine

Answer 10

Question 11

Xanthine

Answer 11

Question 12

Uric acid

Answer 12

Question 13

Biological oxidation

Answer 13

Processes which take place in the mitochondria of the cell

Question 14

What starts the process of biological oxidation?

Answer 14

Transfer of hydrogen from the substrate to a hydrogen carrier coenzyme (NAD+, NADP+) or prosthetic group (FAD, FMN)

Question 15

The most important processes producing reduced coenzymes and prosthetic groups are…?

Answer 15

The citric cycle, beta-oxidation, and the PPP

Question 16

Where does the reduced coenzymes take the hydrogen?

Answer 16

to the respiratory chain in the inner mitochondrial membrane

takes up oxygen and turns to water

Question 17

Aerobe dehydrogenases + example

Answer 17

enzymes that can take hydrogen directly to the molecular oxygen to release H2O2

example: xanthine oxidase

Question 18

How can biological oxidation be demonstrated?

Answer 18

manomeric method

using electrodes that show the changes of the pO2

using a dye that has a different color in its reduced and oxidized form

Question 19

Which redox dye will we use in the lab, and what does it accept hydrogen from?

Answer 19

2, 6-dichlorophenolindophenol

from reduced flavoproteins (FMNH2, FADH2)

Question 20

Answer 20

Reduction of redox indicator

Question 21

What color is the oxidized form of 2,6-dichlorophenolindophenol?

Answer 21

Blue

Question 22

What color is the reduced form of 2,6-dichlorophenolindophenol?

(2,6-dichlorophenolindophenol-H2)

Answer 22

Colorless

Question 23

What does the time of fading of 2,6-dichlorophenolindophenol depend on?

Question 24

What is the substrate in the demonstration of the biological oxidation?

Answer 24

Glucose, lactate or succinate

Question 25

The succinate directly enters the citric acid cycle and is being transformed to \_\_\_(1) by succinate dehydrogenase, while ___ (2) is produced

Answer 25

1 - fumarate 2 - FADH2

Question 26

The lactate is transformed to ___ (1) in the cytoplasm by lactate dehydrogenase, with the production of ___ (2), that is oxidized to acetyl-CoA in the mitochondria and enters the ___ (3) cycle

Answer 26

1 - pyruvate 2 - NADH+H+ 3 - citric acid cycle

Question 27

The glucose entering the glycolysis in the ___ (1) is transformed to ___ (2). During the degradation, the first NADH+H+ is produced by glyceraldehyde-3-P dehydrogenase. The reduced coenzyme is transported by a special transport mechanism to the ___ (3) chain

Answer 27

1 - cytoplasm 2 - pyruvate 3 - respiratory chain

Question 28

What is the essential coenzyme for the process of the biological oxidation?

Answer 28

NAD+

Question 29

Which chain is the main energy producing process of the organism?

Answer 29

the respiratory chain

Question 30

What are the hydrogen donors of the respiratory chain?

Answer 30

The reduced coenzymes and prosthetic groups (NADH+H+, FADH2)

Question 31

What is the last member of the respiratory chain?

Answer 31

Cytochrome a+a3 (cytochrome oxidase)

Question 32

In the detection of cytochrome a+a3, p-phenylenediamine is used as a hydrogen donor, and will at the end of the reaction oxidized into what? And what color will it have?

Answer 32

Violet colored p-phenylenediimine

Question 33

What can the last enzyme of the respiratory chain be inhibited by? (cytochrome oxidase)

Answer 33

cyanide

Question 34

In the brain, where are the mitochondria of the nerve cells found?

Answer 34

Cortex

Question 35

What does the cytochrome oxidase react with to produce a dark violet color in the brain slices?

Answer 35

Nadii’s reagent

Question 36

What does Nadii’s reagent consist of?

Answer 36

P-phenylenediamine and alpha-napthol

Question 37

\_\_\_ oxidase plays a role in the degradation of purine bases

Answer 37

Xanthine oxidase

Question 38

What is produced when xanthine oxidase forwards the hydrogens (carried by prosthetic group FADH2) directly to molecular oxygen?

Answer 38

H2O2, hydrogen peroxide

Question 39

What two reactions are catalysed by xanthine oxidase?

Answer 39

Hypoxanthine -\> xanthine xanthine -\> uric acid