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a. After the CAC, molecules of __ account for most of the energy extracted from glucose
i. These electron escorts link__, which powers ATP synthesis through __
- NADH and FADH2
- glycolysis and the CAC to the ETC
- energy release
i. What is it?
ii. Cristae do what?
1. Most components are __, which exist in __
a. Bound to these are __, nonprotein components essential for the catalytic functions of certain enzymes
- Collection of molecules in the inner membrane of the mitochondria (euk.) or plasma membrane (pro.)
- increase surface area, allowing several ETCs
- multiprotein complexes numbered I through IV
- prosthetic groups
i. During electron transport, carriers alternate between __ and __ states
reduced and oxidized
i. Complex I:
1. Electrons are transferred from __to the first molecule of the ETC in complex I, a __.
a. Explain the progression.
- Flavoprotein--> iron-sulfur protein--> ubiquitone (not a protein, but a small hydrophobic molecule)--> cytochromes whose prosthetic group (heme group) has an iron atom that accepts and donates electrons--> cytochrome a3--> oxygen
1. FADH adds its electrons to the ETC within __, at a __energy level than NADH
a. As a result, even though they both donate the same amount of electrons, the ETC provides __energy for ATP when FADH2 is the donor
Purpose of ETC
- makes no ATP directly
- instead, it eases the fall of electrons from food to oxygen
i. In the inner membrane are __, enzymes that make ATP from ADP and inorganic phosphate
1. Under the conditions of respiration, ATP synthase uses the energy of an __ to power ATP synthesis
a. Power source is a __
i. This process, in which energy is stored in the form of a hydrogen ion gradient across a membrane is used to drive cellular work such as the synthesis of ATP, called __
- ATP synthases
- existing ion gradient
- difference in the concentration of H+ on opposite sides of the inner mitochondrial membrane
i. ATP Synthase
1. Multi-subunit complex with __main parts, each made of multiple polypeptides
a. Protons move one by one into binding sites on one of the parts (the __) , causing it to __
- spin in a way that catalyzes ATP production
What is a major function of the ETC?
establishing the H+ gradient
- 1. It uses the exergonic flow of electrons from NADH and FADH2 to pump H+ across the membrane from the mitochondrial matrix into the intermembrane space
- a. H+ has a tendency to diffuse down gradient; only way is through ATP synthases
1. The energy stored in an H+ gradient across a membrane couples the __
2. How does the ETC pump hydrogen ions?
a. In eukaryotes, the electron carriers are spatially arranged in the inner membrane in such a way that __
- redox reactions of the ETC to ATP synthesis
- The ETC pumps hydrogen ions by certain members of the ETC that accept and release both protons and electrons at certain steps
- H+ is accepted from the mitochondrial matrix and deposited in the intermembrane space
i. H+ gradient is referred to as a__, emphasizing the capacity of the gradient to perform work
1. What does the force do>
- proton-motive force,
- The force drives H+ back across the membrane through the H+ channels provided by ATP synthases
i. In general, what is chemiosmosis?
1. Energy for gradient formation: __
ATP synthesis is the work performed
- chemiosmosis is an energy-coupling mechanism that uses energy stored in the form of an H+ gradient across a membrane to drive cellular work
- exergonic redox reactions
i. Occurs in other places too
1. Chloroplasts use chemiosmosis to__
a. __rather than __drives both __ and the__
- generate ATP during photosynthesis
- chemical energy
- electro flow down an ETC
- resulting H+ gradient formation
1. Prokaryotes generate __ across their membranes
a. They then tap the __to generate ATP and move flagella and pump nutrients and waste across the membrane
- H+ gradients
- proton-motive force
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