Chapter 21- The Proton Motive Force (ATP Synthesis) Flashcards
Where do protons cross for the proton motive force?
Slide 2
They cross the inner mitochondrial membrane from the matrix to the intermemebrane space
What is the structure of ATP synthase?
What makes up F0 and F1?
Slide 4
F0- in the inner mitochondrial membrane, composed of c ring and a protein
C is critical, ranges from 8-15 proteins
A holds c ring
F1- a in F0 attaches to lower B2 in F1 part and this forms the catalytic part of enzyme
Gamma (γ) flows inside a cylinder of 3 alpha and 3 beta proteins
8 proteins total!!!! a, b2, δ, α, β, γ, ε, c
Only c ring, γ, and ε move
What is the open (O) form, loose (L) form, and tight (T) form of ATP synthase,
The 3 catalytic β subunits of the F1 component can exist in 3 conformations:
O- nucleotides can bind to or be released from the β subunit
L- nucleotides are trapped in the β subunit
T- ATP is synthesized from ADP and Pi
Slide 6
What is the relationship between electron transfer and ATP synthesis?
They are a coupled process- they work together at the same time, if one gets inhibited the other does as well
DNP makes the whole synthol membrane and allows molecules to pass the membrane without issues instead of going through ATP synthase
What is the glycerol 3-phosphate shuttle?
Slide 9!!
2 systems which every organism uses to take cytosolic NADH to the transport
dehydrogenase reduces DHP to G3P shuttle produces NAD+
Protons are taken to the mitochondria by another dehydrogenase with another reduction as FAD is a prosthetic group, this produces energy and FADH2
FADH2= 1.5 ATP so process will lose some energy by taking it inside mitochondria
What is the malate aspartate shuttle?
Oxaloacetate is converted to malate by malate dehydrogenase, then transported from intermemebrane space to matrix and converted back to oxaloacetate which produces NADH
Oxaloacetate is converted to aspartate, then back to make the whole cycle move over and over
Takes 2.5 ATP From outside and makes 2.5 ATP inside so no loss of energy!
slide 10
What is Adenine nucleotide translocations (ANT)?
What is phosphate translocase?
ATP moves out of mitochondria and ADP goes in
Anitporter
Phosphate translocase- symporter that flows H+ and others together m
Using 2 transporter proteins s moves ATP out and ADP + Pi in which allows process to continue forward
Slide 11
Go over table of where ATP is lost and gained slide 12
Okay
What inhibits ATP synthase?
Oligomycin inhibits F0
How is ATP synthase regulated?
Regulated with the ability of ADP + Pi
If cell is not high in energy then the cell is high in ATP that is not being used
Need continuous supply of ADP + Pi to continue and determine speed
Slide 14
What happens if electron transport is uncoupled from ATP synthesis?
Heat is generated
This is called nonshivering thermogenesis
Done by uncoupling UCP-1 (thermogenin) which is an integral protein of the inner mitochondrial membrane
Slide 16
