Oxidative Phosphorylation Flashcards
What is oxidation?
Removing of electrons
Where does oxidative phosphorylation occur?
In the mitochondria
What is reduction?
The addition of electrons
What is phosphorylation?
Adding a phosphate group
What happens to ATP when hydrolyzed?
It goes to ADP and Pi
What is ATP used for in the brain?
Electrical transmission
What are muscle and brain rich in and why?
Rich in mitochondria because ATP needs to be recycled
How do mitochondria exist in the cell?
As a network inside the cell
What is the function of mitochondria?
Oxidize carbon fuels to generate energy in the form of ATP
What are the parts of the mitochondria?
Matrix, Cristae, Inner membrane, Intermembrane space, Outer membrane
Which membrane is extremely impermeable in the mitochondria?
The inner membrane. The outer membrane is selectively permeable
What role does oxygen play in the ETC cycle?
It receives the electrons
What are the electron rich power molecules?
NADH and FADH2 - yield the electrons in the electron flow
Where does the NADH in the ETC come from?
The TCA cycle
What vitamins are NADH and FADH2 derived from?
B vitamins - they are energy vitamins.
What happens to the energy of an electron when it jumps from complex to compex
Goes from an high energy to a low energy and that is delta G
What separates the matrix and the intermembrane space?
The inner membrane
Where are the complexes of the ETC located?
The inner membrane
Where do the electrons come from in the ETC?
NADH and FADH2
Describe how metabolism is like burning wood
The burning of wood uses glucose and cellulose as fuel. The fuel is oxidized. Uses oxygen and produces CO2 and water
What is the importance of Co-Q 10 in research?
Co-Q or Q - ubiquinone 10: The ten refers to a specific part of the Q. It has gotten more attention lately because if a person is on statins, that prevents the production of cholesterol in the body by inhibiting the rate determining enzyme in cholesterol biosynthesis. An intermediate in the biosynthesis of cholesterol is required for Co-Q synthesis.
Describe complex 1
NADH - Q oxidoreductase. It has 46 subunits. NADH is the supplier of electrons to the complex and it passes it to Q
Describe complex II
Succinate Q reductase and has 4 subunits. Takes electrons from FADH2 and passes it to Q
Describe complex III
Cytochrome C oxidoreductase: has 11 subunits. Gets its electrons from Q and passes it to cytochrome C
What happens after each passing of the electrons in the ETC?
There are little delta G’s exploding from each hand off. The internall bucket brigade energy is used to pump a proton against its gradient
What complexes transport H across the membrane?
III and IV (also complex I)
What is the pH for the intermembrane space?
Low because of the high amount of protons
Why is the ETC cycle called the oxphos?
Because of the oxidation component of the ETC and the phosphorylation part with the production of ATP
What happens if you place a mitochondria into an acidic media?
It will be tricked into making ATP
How do electrons flow into Complex I? What is FMN?
Electrons flow in complex I from NADH through FMN and a series of iron sulfur clusters to Q. FMN is flavin mono nucleotide and can reversibly bind electrons. FMN hands off electrons to iron sulfur clusters
What is one of the subunits of complex I?
It is flavoprotein and has a FMN attached to it and its the FMN that gets the electron.
How many electrons go through the complex I?
While you start off 2 by 2 because FMN can bind two electrons. Once you get to iron sulfur clusters the electron wiggles through the clusters one at a time
How does the mitochondria produce free radicals which can cause disease?
Mitochondria produce free radicals and its the biproduct of energy metabolism. The inability to pass on the electron precisely to the next component, something could be inappropriately oxidized. Typically a lipid that has a double membrane causing a lipid peroxide and a cascade of free radicals being produced.
Normally where do the electrons that pass through complex I come from?
NADH
What is Co-Q?
It is a 5 carbon compound called an isoprenoid unit.
What makes up Co-Q 10?
Ten isoprenoid units
What is the range of Co-Q one can find in the mitochondria?
7 - 15 Co-Q
What is derived from the cholesterol biosynthesis to make Co-Q?
isoprenoid unit
Why does the inability to make Co-Q cause heart problems?
Heart does not rest so it constantly needs a supply of ATP. This steady supply of ATP comes from mitochondria. So constantly using the mitochondria with the slow production of Co-Q will effect the production of ATP
Are the complexes freely moving about?
False: they are somewhat immobile
What is cytochrome?
Protein with a heme. means heme containing protein. It has a porferin ring structure with iron in the middle. It will be reversibly binding electrons which is opposite of blood
What is the formula for producing delta G?
Delta G=-nF(delta E)
n = # of electrons
F = faraday’s constant
Delta E = reduction potential
What is the reduction potential of NAD+?
-0.32 V
What is the reduction potential of ubiquinone?
+0.10
As you go from NADH all the way to oxygens what is the energy released from each hand off?
.1–.32=+.42
Oxidants-reductants
How does a baby produce warmth?
Brown fat converts electron flow into heat. There is still electron flow and still burning fuel but instead of coming out of AATP machinery a different protein is expressed in that tissue and that protein is UCP 1. Explosions of delta G that eventually dont yield ATP and comes off as heat
How much protons in a baby is used to produce ATP?
Only 20% of protons go through ATP machinery to make enough ATP to keep the tissues alive. UCP-1 has a higher affinity. This protein is expressed in brown fat. The heart nor the brain has the UCP-1
Describe the components of ATPase
F1 - refers to the component that makes the ATP. Subunits of F1 are the greek letters
F0- is the component that translocates proteins. F0 are the regular letters. C ring(10-14 proteins), B2 and A
What 2 things does the ATPase complex do?
- Takes the energy from theh downhill movement of the protons and uses that energy too make ATP.
What makes up the rotator?
C ring and gamma epsilon
What is not included in the stationary component of the ATPase
Everything except the c-ring and epsilon
What drives the process of the ATPase?
ADP and Pi - you can have all the protons in the world out there but wont come in without ADP
What are the parts of the alpha beta complex in ATPase?
T-Tight - synthesizes the ATP
L-Loose - loosely binds to ADP Pi
O-Open - releases new ATP
