Citric Cycle

Question 1

Hydration = ________

Answer 1

Synthesis

Question 2

Dehydration = ________

Answer 2

Decomposition reaction

Question 3

Hydrolysis = ________

Answer 3

Double replacement reaction

Question 4

In a synthesis reaction known as _______, water is added to a double bond.

Answer 4

Hydration

Question 5

In this decomposition reaction, an alcohol heated in the presence of H⁺ splits to form an alkene plus water.

Answer 5

Dehydration

Question 6

Step 1 of the Citric Acid Cycle produces a 6 carbon ionic molecule named citrate. This step also involves the addition of water. What is the classification of this reaction?

Answer 6

Synthesis-hydration

Question 7

Step 1: Oxaloacetate and Acetyl-CoA and water produces?

Answer 7

Citrate (synthesis hydration)

Question 8

How are the 2 compounds citrate and isocitrate related in step 2 of the cycle?

Answer 8

Isomers

Question 9

What are the two reactions involved in the conversion of citrate to isocitrate?

Answer 9

Dehydration followed by Hydration

Question 10

Oxidation:

_____ of Oxygen

_____ of Electrons

_____ of Hydrogens

Answer 10

Gain of Oxygen

Loss of Electrons

Loss of Hydrogens

Question 11

Reduction:

_____ Of Oxygen

_____ of Electrons

_____ of Hydrogen

Answer 11

Loss of Oxygen

Gain of Electrons

Gain of Hydrogen

Question 12

In step 6, the conversion of succinate to fumarate is?

Answer 12

Loss of Hydrogen atoms

(carbon atoms are oxidized)

Question 13

What is the function of FAD in step 6 of the cycle?

Answer 13

Oxidizing agent

Question 14

What are the two oxidizing agents on the citric cycle?

Answer 14

NAD⁺

FAD

Question 15

In step 8, the conversion of malate to oxaloacetate. What is the fate of one of the atoms connected to oxygen in the malate ion?

Answer 15

loses hydrogen

Question 16

What is the function of NAD⁺ in step 8 of the cycle?

Answer 16

Oxidizing agent

Question 17

Identify the type of reaction in step 7.

Answer 17

Hydration

Question 18

What is the loss of CO₂ molecule?

Answer 18

Decarboxylation

Question 19

Step 3 & 4 reactions where oxidation takes place, loss of a CO₂ is referred to as _____________.

Answer 19

Decarboxylation

Question 20

Anything that ends -**ase is what?

i.e. synthase

Answer 20

Catalyst

&

Enzyme

Question 21

What is the function of fumarase in step 7?

Answer 21

Catalyst / Enzyme

Question 22

Most enzymes are named such that they specify the reaction catalyzed. For example, dehydrogenase catalyzes?

Answer 22

The loss of hydrogen atoms

OR

Oxidation reaction

Question 23

The enzyme may also refer to the reactant modified during the reaction. For example, the enzyme fumarase catalyzes the conversion of what?

Answer 23

fumarate ion to malate ion in step 7

Question 24

What pathway best describes the citric acid cycle?

Answer 24

Circular

Question 25

What cell does the citric acid cycle take place in?

Answer 25

Mitochondria

Question 26

Mitochondria, known as the powerhouse, what is produced here?

Answer 26

ATP

Question 27

In citrate (step 1) the alcohol functional group is on the ______ carbon atom.

Answer 27

3rd

Question 28

In isocitrate (step 2) the alcohol functional group is on the _______ carbon atom.

Answer 28

2nd

Question 29

The carbon atom carrying the OH group is attached to just one other carbon atom in a ______ alcohol, to two other carbon atoms in a ________ alcohol, and to three carbon atoms in a _______ alcohol.

Answer 29

1 degree 2 degree 3 degree

Question 30

Citrate can be classified as a ______ degree alcohol.

Answer 30

3 degree

Question 31

Isocitrate can be classified as a ______ degree alcohol.

Answer 31

2 degree

Question 32

Which degree alcohol CANNOT be oxidized? Why?

Answer 32

3 degree The C connected to the OH is not directly connected to an H.

Question 33

During the oxidation reactions of alcohol, _______ hydrogen atoms are \_\_\_\_\_\_\_.

Answer 33

_Two_ hydrogen atoms are _Removed._ *1 hydrogen atom is removed from the -OH group and another is removed from the carbon atom that carries the -OH.*

Question 34

In step 2 of the cycle, Citrate ion is converted to Isocitrate via dehydration and hydration. Why is this conversion necessary?

Answer 34

Citrate is a tertiary (3 degree) alcohol. 3 degree alcohols CANNOT be oxidized. Isocitrate is a secondary alcohol (2 degree). 2 degree alcohols CAN be oxidized. Step 3 of the cycle requires oxidation of alcohols, so citrate is converted to isocitrate in order to perform oxidation.

Question 35

What are the three ATP equivalents that can be harvested to form energy-rich molecules?

Answer 35

NADH FADH₂ GTP

Question 36

What the harvest of one turn of the citric acid cycle?

Answer 36

3 NADH 1 FAHD₂ 1 GTP

Question 37

The change in energy of the reaction of the citric acid cycle is -11 kcal/mol. Is this cycle spontaneous/nonspontaneous? Is this cycle exo/endothermic?

Answer 37

Spontaneous Exothermic *(because of the -11kcal/mol)*

Question 38

A measure of the speed with which reaction products form?

Answer 38

Reaction rate

Question 39

The energy required to cross the energy barrier between reactants and products?

Answer 39

Activation Energy | (E_act)

Question 40

A substance that speeds up a reaction without itself being altered?

Answer 40

Catalyst

Question 41

What are 3 ways to alter the rate of a chemical reaction?

Answer 41

Increase temp. Increase concentration Add catalyst

Question 42

What of the two graphs best describe overall citric acid cycle

Answer 42

The graph on the left because it shows a release of energy *(citric cycle = releases of energy)* Exothermic: The energy is released. 11kcal/mol is the release of energy.

Question 43

How does a catalyst increase the speed of a reaction?

Answer 43

It lowers the activation energy of the reaction by changing the path the reaction takes.

Question 44

How do you distinguish between a reaction energy diagram with a catalyst and one without?

Answer 44

A large amount of "activation energy" = without catalyst Small amount of "activation energy" = with catalyst