0304 Making ATP substrate level and oxidative phosphorylation Flashcards
ATP contains high energy phosphate bonds High energy cost in synthesising ATP Substrate level phosphorylation – rapid but short-term & inefficient Oxidative phosphorylation is efficient & O2 requiring OxPhos occurs in the mitochondria Reduced co-factors provide energetic electrons to the ETC ETC passes electrons along energy gradient Passage of electrons produces proton gradient ATP synthase uses chemical and osmotic gradient ADP entry into mitochondria set
What does ATP stand for? What 3 groups is it made of
ATP = adenosine triose phosphate. The groups are adenine, ribose and a triphosphate group
Why does the generation of ATP required coupling with another reaction
Phosphorylation of ATP from a substrate requires coupling because the formation of ATP is unfavourable (G about 30) so it needs to be paired with a favourable reaction (G < -30)
List one example of a substrate that is used in substrate level phosphorylation
Creatine-phosphate (turns into creatine)
What is the name of the famiyl of enzymes that phosphorylate ATP from a substrate
Kinsases
Give an example of when substrate level phosphorylation is the primary source of energy
During the initial stages of strenuous excercise
Compared to oxidative phosphorylation, is substrate level phosphorylation a rapid or slow response for ATP generation
Substrate level phosphorylation is rapid generation of ATP
Where in the cell does oxidative phosphorylation occur
In the mitochondria (specifically the inter mitochondrial space)
What is the gateway molecule through which carbohydrates, proteins and fatty acids enter the TCA cycle
Acetyl CoA
Briefly describe oxidative phosphorylation
The phorylation of ATP from ADP using energy from a proton generated by oxidative reactions via 4 protein complexes in inner mitochondrial membrane
What is the name of the 4 protein complexes in inner mitondrial membrane
- NADH reductase
- Succinate dehydrogenase
- Cytochrome C reductase
- Cytochrome C oxidase
Due to the proton gradient, where is the concetration of H+ protons higher: the intermembrane space or the mitochondrial matrix
The intermembrane space has a higher [H+]
What is the name of the 2 mobile membrane carriers that move electrons between the protein complexes in the inner mitochondrial membrane
Ubiquinone and Cytochrome C
How is ATP transported out of the mitochondrial matrix and what is one consequence of this transport (think electrogenic gradients)
ATP swapped into the intermembrane space for ADP. Because ATP -4 is more negative than ADP -3 , there is slight dissipation of the electrostatic gradient due to H+ concetration
