Glycolysis and Redox reactions Flashcards
What is cooperative allostery?
Two or more subunits work on an enzyme
It is a cooperative transition involves two shape changes
Why do catabolic pathways need to be long?
It allows them to release energy slowly- that is the only for cells to properly capture some of the energy
Burning Glucose to carbon dioxide- what is more efficient way to do it?
It is best to split reaction into many steps- only releasing small amount of energy at a time (enough to keep reaction going and store some energy).
When glucose is oxidized, how much energy goes wehre?
- 1/2 is collected in ATP
- 1/2 is released as heat
- 686 kcal/mol total
What are the two types of glucose oxidation?
- Aerobic (cellular respiration)
- Anaerobic (fermentation- absence of oxygen)
Where do electrons go in regards to the carbon atom in the oxidation of glucose?
Electrons move further away from the carbon atom
- Number of C-H bonds decreases and number of C-O bonds increases
How do we recognize oxidations?
- Increase in charge! (ex: 2+ -> 3+)
In what form is oxidation energy stored?
- In the intermediate form NAD, which is reduced to NADH
How does NADH behave?
- Comes from the reduction of NAD
- When it is oxidized it releases energy
It is a temporary electron carrier
Formula for oxidation and reduction of Nad+/Nadh
NAD+ + H+ + 2e -> NADH
red->
ox
What is redox potential?
The tendency to lose or gain electrons
What is the best electron acceptor?
Oxygen
What are the 2 stages of glycolysis?
- Investment of ATP to activate the sugar. It is the splitting of C6 into 2 C3 (ENERGY CONSUMING)
- Oxidation of the C3, giving NADH (reduction of NAD+). This releases a lot of free energy.
How much ATP do cell resp and fermentation yield?
Cell resp yields 29 ATP
Fermentation yields 2 ATP
What is the name of the 6C and 3C it becomes during glycolysis? What aids this reaction?
Glucose splits into 2 pyruvate
This is aided by phosphate
Produces 2 ATP
Where does oxidation of Pyruvate take place?
The mitochondria
Where does glycolysis take place?
What is the end product of glycolysis and where does it go?
The cytosol
End product is pyruvate- which is then oxidized in the mitochondrial matrix to acetyl coA
What is acetyl coA?
Acetyl coA is a an energy carrier
transfers 2C group to another molecule at start of citric acid cycle
What is the purpose of the citric acid cycle?
Finishes oxidation of glucose by converting acetyl CoA to 2 CO2
What catalyzes the citric acid cycle?
Is it a redox reaction?
Dehydrogenases
It is NOT a redox reaction
What is the end result of citric acid cycle?
- 3 NADH, 1 FADH2, 1 GTP (ATP)
Where does NADH go after citric acid cycle?
NADH goes to the electron transport chain!
Converts to NAD+ to continue citric acid cycle
Makes ATP
What takes up electrons from FADH2?
- Ubiquinone takes up e from FADH2 from complex 2
- It carries electrons from one complex to the next
How is ATP “spent”
ATP is converted to ADP via hydrolysis- a phosphate is kicked off and replaced by OH, releasing energy
