Citric Cycle Flashcards
Hydration = ________
Synthesis
Dehydration = ________
Decomposition reaction
Hydrolysis = ________
Double replacement reaction
In a synthesis reaction known as _______, water is added to a double bond.
Hydration
In this decomposition reaction, an alcohol heated in the presence of H+ splits to form an alkene plus water.
Dehydration
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?
Synthesis-hydration
Step 1: Oxaloacetate and Acetyl-CoA and water produces?
Citrate (synthesis hydration)
How are the 2 compounds citrate and isocitrate related in step 2 of the cycle?
Isomers
What are the two reactions involved in the conversion of citrate to isocitrate?
Dehydration followed by Hydration
Oxidation:
_____ of Oxygen
_____ of Electrons
_____ of Hydrogens
Gain of Oxygen
Loss of Electrons
Loss of Hydrogens
Reduction:
_____ Of Oxygen
_____ of Electrons
_____ of Hydrogen
Loss of Oxygen
Gain of Electrons
Gain of Hydrogen
In step 6, the conversion of succinate to fumarate is?
Loss of Hydrogen atoms
(carbon atoms are oxidized)
What is the function of FAD in step 6 of the cycle?
Oxidizing agent
What are the two oxidizing agents on the citric cycle?
NAD+
FAD
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?
loses hydrogen
What is the function of NAD+ in step 8 of the cycle?
Oxidizing agent
Identify the type of reaction in step 7.
Hydration
What is the loss of CO2 molecule?
Decarboxylation
Step 3 & 4 reactions where oxidation takes place, loss of a CO2 is referred to as _____________.
Decarboxylation
Anything that ends -**ase is what?
i.e. synthase
Catalyst
&
Enzyme
What is the function of fumarase in step 7?
Catalyst / Enzyme
Most enzymes are named such that they specify the reaction catalyzed. For example, dehydrogenase catalyzes?
The loss of hydrogen atoms
OR
Oxidation reaction
The enzyme may also refer to the reactant modified during the reaction. For example, the enzyme fumarase catalyzes the conversion of what?
fumarate ion to malate ion in step 7
What pathway best describes the citric acid cycle?
Circular
What cell does the citric acid cycle take place in?
Mitochondria
Mitochondria, known as the powerhouse, what is produced here?
ATP
In citrate (step 1) the alcohol functional group is on the ______ carbon atom.
3rd
In isocitrate (step 2) the alcohol functional group is on the _______ carbon atom.
2nd
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.
1 degree
2 degree
3 degree
Citrate can be classified as a ______ degree alcohol.
3 degree
Isocitrate can be classified as a ______ degree alcohol.
2 degree
Which degree alcohol CANNOT be oxidized?
Why?
3 degree
The C connected to the OH is not directly connected to an H.
During the oxidation reactions of alcohol, _______ hydrogen atoms are _______.
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.
In step 2 of the cycle, Citrate ion is converted to Isocitrate via dehydration and hydration. Why is this conversion necessary?
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.
What are the three ATP equivalents that can be harvested to form energy-rich molecules?
NADH
FADH2
GTP
What the harvest of one turn of the citric acid cycle?
3 NADH
1 FAHD2
1 GTP
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?
Spontaneous
Exothermic
(because of the -11kcal/mol)
A measure of the speed with which reaction products form?
Reaction rate
The energy required to cross the energy barrier between reactants and products?
Activation Energy
(Eact)
A substance that speeds up a reaction without itself being altered?
Catalyst
What are 3 ways to alter the rate of a chemical reaction?
Increase temp.
Increase concentration
Add catalyst
What of the two graphs best describe overall citric acid cycle
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.
How does a catalyst increase the speed of a reaction?
It lowers the activation energy of the reaction by changing the path the reaction takes.
How do you distinguish between a reaction energy diagram with a catalyst and one without?
A large amount of “activation energy” = without catalyst
Small amount of “activation energy” = with catalyst
