Electron Transport Flashcards
The electron transport/oxidative phosphorylation pathway consists of a chain of ___ and other molecules that results in a high yield of ___ ___
enzymes, ATP molecules (metabolic energy)
In eukaryotic cells, these processes take place in ____
mitochondria
The electron tranport/oxidative phosphorylation proteins are ___ ____ proteins of the inner mitochondrial membrane
integral membrane
During electron transport, a __ ___ is established across the inner mitochondrial membrane.
protein gradient
During oxidative phosphorylation, the movement of protons through the ___ ___ enzyme in the inner mitochondrial membrane leads to the synthesis of ___ ___
ATP synthase, ATP molecules
The TCA cycle and electron transport/oxidative phosphorylation pathway are linked by the __ and ___ bound to NADH and FADH2
protons and electrons
The TCA cycle and electron transport/oxidative phosphorylation pathway are linked by the protons and electrons bound to __ and ___
NADH and FADH2
NADH binds to a binding site on complex ___
one
FADH2 bonds to a binding site on complex __
two
How many complexes are there in the electron transport/oxidative phosphorylation pathway?
four complexes
Cytochrome C molecules transfer protons and electrons between what two complexes?
3 + 4
All four complexes are stimulated by the ____ that pass through them
electrons
Molecular oxygen (O2) with complex ___ creates water (H2O)
four
O2 + Complex 4 = ____
H2O
Protons (H+) are brought from the mitochondrial matrix to the ____ ____
Intermembrane space
The movements of protons from the mitochondrial matrix to the intermembrane space create a high concentration of ___ in the intermembrane space
protons
Once enough protons have built up in the intermembrane space, the protons can move down the concentration gradient via ____
ATP synthase
What major event will stimulate the ATP synthase in making ATP?
ATP synthase
ADP + phosphate groups = ___
ATP
What is ATP synthase?
Adding a phosphate to an ADP group to create ATP
NADH is a carrier for ___ and ___ in electron transport
protons and electrons
NADH —->
NAD+ + H+ + 2e-
Protons and electrons are both required in the reaction involving oxygen:
1/2 O2 + 2H+ + 2e- —> H2O
NAD+ and NADH have central roles in ___ ___ in mitochondria.
energy generation
The structure of NAD+ has two _____ linked
nucleotides
Nicotinamide Adenine Dinucleotide is also known as ___
NAD+
NAD stands for ___ ___
nicotinamide adenine dinucleotide
the adenine in NAD is ribose/dexoyribose?
ribose
what are the 3 components of the adenosine of NAD+?
adenine, ribose, 2 phosphate groups
the base nicotinamide is a modification of what B vitamin?
niacin
what is the modification to niacin that produces micotinamide?
carboxyl has amino group added to give amide
where does the proton bind when NADH is produced from NAD?
next to hydrogen at the top of nicotinamide
This is the location of the enzymes of the TCA cycle and electron transport/oxidative phosphorylation
Mitochondria
What are the four layers of the mitochondria?
Outer membrane, inner membrane, intermembrane space, matrix
The enzymes of electron transport and oxidative phosphorylation are components of the ___ ____ membrane
inner mitochondrial
Where are the TCA cycle enzymes located?
In the matrix
how many mitochondria are in each cell?
1,000-2,000
what type of cell has the most mitochondria?
liver
the ____ ____ of the mitochondria has folds that provide extensive surface area for electron transport and oxidative phosphorylation to occur
inner membrane
What is the gap between the outer membrane and the inner membrane?
The intermembrane space
The inter-mitochondria membrane is highly ___
folded
In the electron transport chain, electrons and protons are transferred between the portein complexes by ___ _ and ___ _
Coenzyme Q (UQ)
cytochrome c (cytc)
how many protein subunits are part of complex 1?
greater than 30 (44 in humans)
What is a small globular protein?
A small globular protein
cytochrome C works in the hydrophilic space of the ____ _____
inner membrane
when cytochrome C is alternating between complexes 3 and 4, it also moves ___ and ____
protons, electrons
when CytC is oxidized, it gives up the ____
proton and some electrons
coemzyme Q is a _____ lipid that is insoluble in the matrix
terpene
what other molecule in addition to CytC is transporting electrons and protons?
Coenzyme Q
when NADH+H+ becomes NAD+, what two places do protons go?
across gradient to intermembrane space, to the cycle of coenzyme Q and into protein 3
what reaction that also occurs in the TCA cycle occurs during electron transport?
succinate to fumarate
where does the reaction of succinate to fumarate take place?
complex 2
Coenzyme Q: When it binds protons and electrons =
UQH2
Coenzyme Q: When gives up protons and electrons =
UQ
NADH has a binding site on complex ____
one
Protons can go directly from the matrix to the __ __ __
inter membrane space
Protons can be diverted and go to a different _____, and then be transported to the inter membrane space
complex
Complex 2 is NOT involved in transporting protons into the ___ ____ ____
inter membrane space
Complex 2 is involved in transporting protons from ___
complex 3 to complex 4
complex ____ does not transport protons from the matrix to the intermembrane space
2
what is the enzyme name of complex 1?
NADH coenzyme Q reductase
what is the enzyme name of complex 2?
succinate coenzyme Q reductase
what is the enzyme name of complex 3?
coenzyme Q cytochrome c reductase
what is the enzyme name of complex 4?
cytochrome c oxidase
What complexes transport proteins across the inner mitochondrial membrane?
Complex 1, 3 , 4
What happens when protons are transported across the inner mitochondrial membrane?
Generates a proton gradient across the membrane
The transport of electrons and protons between the protein complexes is brought about by:
- coenzyme Q (CoQ or UQ)
- cytochrome c (Cytc)
NADH coenzyme Q reductase
complex 1
succinate coenzyme Q reductase
complex 2
coenzyme Q cytochrome c reductase
complex 3
cytochrome c oxidase
complex 4
how many protein subunits are in complex 1?
> 30
how many protein subunits are in complex 2?
4
how many protein subunits are in complex 3?
11
how many protein subunits are in complex 4?
13
Complex 1 is called NADH coenzyme Q reductase, and is also known as ___
flavoprotein 1
Why is complex 1 also known as flavoprotein 1?
it contains the coenzyme flavin mononucleotide (FMN)
Complex 2 is called succinate-coenzyme Q reductase, and is also known as ___
flavoprotein 2
Why is complex 2 also known as flavoprotein 2?
it binds the coenzyme flavin adenine dinucleotide (FAD)
FMN ad FAD are derivatives of ____
riboflavin (B2)
what modification occurs to riboflavin to produced FMN?
addition of phosphate
what modification occurs to riboflavin to produce FAD?
addition of ADP covalently bound
what is another name for ATP synthase?
F1F0 ATP synthase
what oval structures project down from ATP synthase into the mitochondrial matrix?
F1 spheres
what portion of ATP synthase is the integral membrane protein?
F0
what part of the ATP synthase stimulates ATP synthesis?
F1
The F1 unit catalyzes ___ ___
ATP synthesis
The F0 unit forms a transmembrane pore or channel which protons move to drive ___ ___
ATP synthesis
the ____ subunits of ATP synthase is spinning in the membrane at 6,000 rps
c
what is the movement of the c subunits of ATP synthase stimulated by?
movement of protons through middle of the structure
the ____ _____ is the central part of ATP synthase where protons travel to get into the matrix
gamma stalk
the rotation of the c and gamma stalk subunits brings about ______ _______ of alpha and beta subunits to uncover the active site and allow for transformation of ADP to ATP
conformational change
how are the active sites of the alpha and beta enzymes of ATP synthase uncovered?
rapid rotation of c and gamma stalk
what subunits keep the ATP synthase unit together?
A, B, delta, epsilon
how many alpha and beta units are in the F1 spheres?
3
how many gamma stalks are present?
1
how many delta and episilon units are presents?
1
how many A units are presents?
1
how many B units are presents?
2
how many C units are present?
10 (ish)
What are the four key protein subunits?
c, gamma, alpha, and beta
Where are the c subunits located?
In the inter mitochondrial membrane
alpha and betta are the enzymes that _____
synthesize ATP
What is the total number of subunits in the F1 spheres?
9
What is the total number of subunits in the F0 spheres?
13
What subunits make up the F0 integral membrane protein?
a,b,c
what complexes does UQ (coenzyme Q) move protons between?
A
1 and 3, 2 and 3
what complexes does cytochrome c move between?
3 and 4
What complex oxidizes oxygen?
complex 4
The electron transport/oxidative phosphorylation enzyme produce a __ ___
protein gradient
When a protein gradient is created, a ____ ____ in ATPsynthase occurs and leads to the production of ATP
conformational change
glycolysis occurs in the ___ of the cell whereas energy generation occurs in the ______
cytosol, mitochondria
the NADH produced by glycolysis in the cytosol cannot pass through the ____ ____ _____
inner mitochondrial membrane
what mechanism transfers NADH from glycolysis in the cytosol to the mitochondrial matrix?
malate-aspartate shuttle
the ____ of NADH and free H+ link to _____ in the cytosol
H+, oxaloacetate
the H+ of NADH and free H+ linking to oxaloacetate produce _____
malate
in the mitochondrial matrix once the malate has passed through, the H+ is added back to _____ to produce NADH+
NAD+
Is malate readily transported into the mitochondrial matrix?
yes
When is NADH transferred from the cytosol into the matrix?
When the H+ is added back to NAD+ to make NADH
