-
· Because __ phosphorylation keeps the recycling going
· The electron flow in oxidative phosphorylation takes place in __ that are embodied in the __, called the __
o The overall reaction is __
- we need a large amount of ATP, oxidative
- four large protein complexes
- inner mitochondrial membrane
- ETC
- exergonic
-
o Three of the complexes of the ETC use energy released by __. Energy is __.
§ The resulting unequal distribution of protons generates a __ and a __ that creates a __. ATP is synthesized when?
- the electron flow to pump protons from the mitochondrial matrix into the cytoplasm.
- transformed
pH gradient and a transmembrane electrical potential
protn-motive force
protons flow back to the mitochondrial matrix through an enzyme complex
-
· Thus, the __ and __ are coupled by a proton gradient across the inner mitochondrial membrane
o Collectively, the generation of __by the CAC, their flow through the respiratory chain, and the accompanying synthesis of ATP is called __
oxidation of fuels and the phosphorylation of ADP
high-transfer-potential electrons
respiration or cellular respiration
-
· The purpose of the CAC is to __; and oxidative phosophorylation converts the __ into __
· Mitochondria have an __ and an __ with folds called __
- generate high-energy electrons
- energy of these electrons into ATP
- outer membrane
- inner membrane with folds called cristae
-
o There are two compartments: __; and, there’s the __, which is bounded by the inner membrane
§ The __is the site of most of the reactions of the __ and __
§ Oxidative phosphorylation takes place in the __ due to __, which provide more sites for the ETC
- the intermembrane space between the outer and inner membranes
- matrix
- matrix
- CAC and fatty acid oxidation
- membrane due to cristae
-
o the outer membrane is __ because it contains many copies of mitochondrial __, called __
§ __plays a role in the __—usually anionic species like phosphate, chloride, etc.—across the outer membrane
o The inner membrane is __to nearly all ions and polar molecules
- permeable to most small molecules and ions
- porin
- VDAC< for voltage-dependent anion channel
- VDAC
- regulated flux of metabolites
impermeable
-
· A large family of transporters shuttles metabolites like __(3)__ across te inner mitochondril membrane
o The two faces of this membrane are the __ and __, or __ and __ sides because the membrane potential is __on the matrix side, but __on the cytoplasmic side
· In prokaryotes, the __ and __ are on the __, the inner of two membranes. The outer membrane of bacteria is __
- ATP, pyruvate, and citrate
- matrix side and the cytoplasmic side
- N and P
- negative
- positive
- electron-driven proton pumps and ATP synthesizing complex
- cytoplasmic membrane
- permeable
-
· Proof of endosymbiosis:
- - mitochondria have their own DNA, which encodes proteins and RNA; and, they have proteins encoded by nuclear DNA
- - the double-membrane circular DNA and mitochodrial-specific transcription and translation
- -Richettsia prowazekki as the most mitochondrial like bacterial genome
-
o The evidence that modern mitochondria result from a single event comes from examination of the __, which contains 97 genes, of which 62 specify proteins
§ Mitochondrial genomes have a small fraction of bacterial genes—__%
- most bacteria-like mitochondrial genome, that of the protozoan Reclinomonas Americana
- 2
-
· Primary function of CAC: __
o In oxidative phosphorylation, electrons from __ and __ are used to __
§ The highly __ reduction of molecular oxgen by NADH and FADH2 is accomplished by a number of __, which take place in a set of membrane proteins known as the __
- generate NADH and FADH2 by oxidizing acetyl CoA
- NADH and FADH2
- reduce molecular oxygen to water
- exergonic
- electron-transfer reactions
- ETC
-
· In oxidative phosphorylation, the electron-transfer potential of NADH or FADH2 is converted into the __
o Te measure of phosphoryl-transfer potential is __ for the __
§ The corresponding expression for the electron-transfer potential is __, the __
- phosphoryl-transfer potential of ATP
- dGo’
- hydrolysis of the activated phosphoryl compound
- E’0
- reduction potential (redox potential)
-
· The __ is an electrochemical concept; and, __ exist
o The reduction potential can be determined by doing what?
§ The __ consists of an electrode immersed in a solution of 1 M oxidant and 1 M reductant
- reduction potential
- redox couples
- measuring the electromotive force generated by an apparatus called a sample half-cell connected to a standard reference half-cell
- sample half-cell
-
· The __ consists of an electrode immersed in a 1 M H+ solution that is in equilibrium with H2 gas at 1 atm of pressure
· The electrodes are connected to a __, and an __ allows ions to move from one half-cell to the other, establishing __ between the half-cells. Electrons then flow from one-half cell to the other through the wire connecting the two half-cells to the voltmeter.
- standard reference half-cell
- voltmeter
- agar bridge
- electrical continuity
-
o Electrons flow from the __ to the __, and the sample-cell electrode is __with respect to the standard-cell electrode
§ The __ of the X; X- couple is the observed voltage at the start of the experiment
§ The __ of the H+: H2 couple is defined to be 0 volts
- sample half-cell to the standard reference half-cell
- negative
- reduction potential
- reduction potential
-
· In oxidation-reduction reactions, the donor of electrons, in this case X, is called the __, whereas the acceptor of electrons, H+ here, is called the __
- reductant or reducing agent
- oxidant
-
· A negative reduction potential means what?
· A positive reduction potential means __
· A strong reducing agent is poised to __ and has a __, whereas a strong oxidizing agent is ready to __ and has a __
that the oxidized form of a substance has lower affinity for electrons than does H2, as in the preceding example
that the oxidized form of a substance has higher affinity for electrons than does H2
- donate electrons
- negative reduction potential
- accept electrons
- positive reduction potential
-
· The standard free-energy change dGo’ is related to the change in reduction potential dE’0 by
o dGo’ = -nFdE’0
§ n is the number of electrons transferred; F is a __, dE’0 is in volts, and dGo’ is in kj or kc per mole
o the free-energy change of an oxidation-reduction reaction can be readily calculated from the __
- proportionality constant called the faraday
- reduction potentials of the reactants
-
· the driving force of oxidative phosphorylation is the __. The release of free energy is substantial.
o The released energy for __ is used to __ that is then used for the __ and __
electron-transfer potential of NADH or FADH2 relative to that of O2.
- hydrolysis of ATP
- generate a proton gradient
- synthesis of ATP and the transport of metabolites across the mitochondrial membrane
-
· The __ for a species moving fromone side of a membrane where it is at concentration c1 to the other side where it is at a concentration c2 is given by
o dG=RTln(c2/c1)+ ZFdV
§ Z is the __ and dV is the __
· Under typical conditions for the inner mitochondrial membrane, the pH outside is __ than inside and the membrane potential is __, the outside being __.
- free-energy change
- electrical charge of the transported species
- potential in volts across the membrane
- 1.4 units lower
- 0.14 V
- positive
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