ETC and ATP synthesis Flashcards
The inner membrane of the mitochondria is permeable to small molecules and ions (T/F)?
False! Only the outer membrane is open to small molecules and ions through porins.
Name 4 electron acceptors/carriers that bring electrons to the ETC.
NAD+, NADP+, FAD+, FMN
What cycle/pathway serves the purpose of regenerating NADPH?
Pentos phosphate pathway
The electron transport chain can transfer what 3 things?
Electrons Hydrogen atoms (H = H+ + e-) Hydride atoms (H- = H+ + 2e-)
What are three other electron carrying molecules (Besides NAD+, NADP+, FAD+, FMN)
Ubiquinone (hydrophobic)
Cytochromes (Protein containing heme + iron)
Iron-Sulfur proteins
A reducing equivalent means:
Electrons transferred (# electrons that can be removed to reduce molecule) Ex: H = H+ + e-, hydrogen has 1 reducing equivalent. A double electron equivalent would be a hydride (H- = H+ + 2e-)
Where is Ubiquinone synthesized?
In the cells, so is not a vitamin. It’s also known as Coenzyme Q.
Ubiquinone can carry how many electrons? When fully reduced, what is ubiquinone called?
2 electrons which can be donated one at a time.
When fully reduced, ubiquinone is known as Ubiquinol, QH2
Ubiquinone can accept 2 electrons in the form of a hydride (H-) (T/F)?
False, Only NAD+ or NADP+ can accept H-. Ubiquinone has two opposing positions that require a hydrogen (one e-)
Cytochromes do how many electron transfers?
1 e-
Heme A carries what R group?
An aldehyde! (CHO)
A is for aldehyde
Heme C carries what R group?
Cystine!
C is for cystine
Iron-sulfur proteins can transfer how many electrons?
1 e-
Iron sulfur’s reduction potential is tuned by what?
protein/aminoacid
What is the ultimate acceptor?
oxygen
Electrons flow from the ______ reduction potential (E) to the ______
Lowest E reduction potential to the highest
Cytochorme’s reduction potential depends on their heme environment (T/F)?
True
What are the initial electron donors of oxidative phosphorylation?
NADH and FADH2
Where do NADH and FADH2 get their electrons from?
CAC and beta oxidation (some amino acid oxidation)
When O2 is fully reduced ETC, what does it become?
H2O. Because Electron donor is 2H+ and electron acceptor is O2
The ETC can accept electrons from NADPH (T/F)?
False! NADPH must be converted to NADH before ETC can accept electrons
What is complex 1 in ETC called?
NADH dehydrogenase
What is complex 2 in ETC called? What does it do?
Succinate dehydrogenase. Converts succinate to fumarate.
What is complex 3 in ETC called?
Ubiquinone cytochrome c oxidoreductase.
