Lecture 4 Flashcards
What type of reaction is one that breaks down bigger molecules into smaller ones?
An exergonic reaction
What type of reaction is one that builds up bigger molecules from smaller ones?
An endergonic reaction
Which reaction is more favourable, and exergonic or an endergonic one?
Exergonic - breaking down bigger molecules to smaller ones
What does it mean if Gibbs free energy (delta G) is below 0?
It means that the reaction is favourable and will happen spontaneously
What does it mean if Gibbs free energy (delta G) is above 0?
It means that the reaction will not happen spontaneously and it requires energy input
What are the 2 steps that comprise oxidatitive phosphorylation?
- The electron transport chain
- Chemiosmosis
Where do these metabolic processes take place:
- Glycolysis
- Krebs cycle
- Electron transport chain
- Glycolysis - in the cytoplasm of a cell
- Krebs cycle - in the matrix of the mitochondria
- Electron transport chain - in the outer membrane of the mitochondria
What is the process called that takes pyruvate to Acetyl Co?
Oxidative decarboxylation
What is a reaction know as if it involves both anabolism and catabolism?
An amphibolic reaction
What is a refuelling/ self replenishing reaction called?
An anaplerotic reaction
What does the electron transport chain create that drives oxidative phosphorylation?
It creates a chemiosmotic gradient
What ion gradient is used in oxidative phosphorylation and what does it help to form?
The Hydrogen ion gradient that was formed by the ETC is used by ATP synthase to form ATP
What is happening during the ETC?
H+ ions are being pumped out of the matrix of the mitochondria and into the intermembrane space creating an unbalancing of the charges of the 2 places over the membrane
What are the four complexes involved in the ETC and what do they all do?
- Complex I - Passes e- and pumps out H+
- Complex II - Passes e- but DOESNT pump out H+
- Complex III - Passes e- and pumps out H+
- Complex IV - Passes e- and pumps out H+
What are the 4 complexes in the ETC called?
I - NAD dehydrogenase
II - Succinate Q reductase
III - Cytochrome C Bc1
IV - Cytochrome C Oxidase
What happens at the first complex?
- NAD is fed into he complex (2NADH—> 2NAD+ +2H+)
- Both of the e- are transferred to ubiquinone where a reaction happens ( 2e- + CoQ —> reduced CoQ
- Both of the protons (H+) are pumped across the IMM into the IMS
What happens at complex 2 of the ETC?
- FADH2 is fed into the complex (FADH2 —> +2H+ +2e-
- However being the 2nd complex of the ETC the protons DO NOT get pumped across the IMM
What happens at complex 3 of the ETC?
- The e- taken from reduced CoQ (reduced CoQ[2e-] —> CoQ +2e-)
- The CoQ (ubiquinone) then goes back to complex to to complete the cycle again
- 2 H+ are pumped out of the IMM into the IMS
What happens at complex 4 of the ETC?
- (O2 + 4H+ + 4e- —>2H20)
- It also pumps H+ ions across the IMM into the IMS
