energy generation in mitochondria

NADH donates _ for synthesis of ATP

high-energy electrons

electron carriers __ transfer electrons that they have gained by oxidizing other molecules to the ETC

NADH FADH2

the specialized chain of electron carriers is embedded where

the inner membrane of the mitochondrion

as electrons pass through the series of electron acceptor and donor molecules that forms the chain they _

fall to successively lower energy states

as electrons pass through the series of electron acceptor and donor molecules that forms the chain they fall to successively lower energy states

the energy released is used to drive

H+ ions across the membrane

as electrons pass through the series of electron acceptor and donor molecules that forms the chain they fall to successively lower energy states

the energy released is used to drive

This generates a

transmembrane gradient of H+ ions

as electrons pass through the series of electron acceptor and donor molecules that forms the chain they fall to successively lower energy states

the energy released is used to drive

This generates a transmembrane gradient of H+ ions that serves as a

source of energy for phosphorylation of ADP to generate ATP

as electrons pass through the series of electron acceptor and donor molecules that forms the chain they fall to successively lower energy states

the energy released is used to drive

This generates a transmembrane gradient of H+ ions that serves as a source of energy for phosphorylation of ADP to generate ATP

the electrons are added to — molecules which combines with — to produce _

O2, H+, H2O

energy generation in mitochondria slide

cells obtain their energy by a _base mechanism

membrane

The essential requirements for harnessing energy in the form of ATP are

A membrane containing a series of electron carriers (ETC), a pump protein, and an ATP synthase
Sources of high-energy electrons derived from the oxidation of food and of protons

the pump harnesses the energy of electron transfer to

pump protons derived from water creating a proton gradient across the membrane

the proton gradient serves as a

energy store and is used to drive the synthesis of ATP by the ATP synthase

stage one of harnessing energy from ATP

energy of electron transport is used to pump protons across the membrane

stage two of harnessing energy from ATP

energy in the proton gradient is harnessed by ATP synthase to make ATP

cells obtaining their energy by a membrane-based mechanism slide

what are batteries powered by

chemical reactions based on electron transfers

chemiosmotic coupling

the linkage of electron transport, proton pumping, and ATP sythesi was formerly called the chemiosmotic hypotehsis

chemiosmotic mechanism allow the cell to

harness the energy of electron transfers in the same way that energy stored in a battery can be harnessed to do useful work

battery power slide

mitochondria are located near

sites of high ATP utilization

characteristics of mitochondria slide

contain own DNA and RNA, constantly change shape and position in the cell, position varies between cel types depending on where the majority of ATP is needed

characteristics of ATP slide

how many compartments is a mitochondria organized into

4

what are the 4 compartments of a mitochondria

matrix, inner membrane, outer membrane, intermembrane space

matrix of mitochondria

this space contains a highly concentrated mixture of hundreds of enzymes, including those required for the oxidation of pyruvate and fatty acids and for teh citric acid cycle

inner membrane mitochondria

folded into numerous cristae, the inner membrane contains proteins that carry oxidative phosphorylation, including the electron transport chain and ATP synthase that makes ATP. It also contains transport proteins that move selected molecules into and out of the matrix

out membrane mitochondria

because it contains large, channel-forming proteins(called porins), the outer membrane is permeable to all molecules of 5000 daltons or less

intermembrane space mitochondria

this space contains several enzymes that use the ATP passing out of the matrix to phosphorylate other nucleotides. It also contains proteins that are released during apoptosis.

how is mitochondria organized

the protons in water are highly _

mobule

protons in water slide

NADH donates its electrons to the

ETC

NADH donating its electrons slide

how many electrons does NADH donate to the ETC

2

protons are pumped across the

inner mitochondrial membrane

protons are pumped across the inner mitochondrial membrane slide

electrons are transferred through __ in the ETC

3 respiratory enzyme complexes in the inner mitochondrial; membrane

what enzyme complexes make up the ETC

NADH dehydrogenase complex, cytochrome c reductase complex, cytochrome c oxidase complex

NADH dehydrogenase complex accepts _

electrons from NADH in the form of a hydride ion

enzymes in the NADH dehydrogenase complex catalyze what reaction

H- → 2e- + H+

teh three respirator enzymes of the ETC slide

the __ of the electron carrier allows for the transfer to drive proton pump

orientation

as an electron passes along an electron transport chain, it can

bind and release a proton at each step

orientation of electron carrier slide

what do quinone do

carry electrons within the lipid bilayer

With each of the 3 respiratory enzyme complexes, electrons move mainly between

metal atoms that are tightly bound to the proteins

Electrons are carried between the different respiratory complexes by

molecules that diffuse along the lipid bilayer, picking up electrons from one complex and delivering them to another

Quinones are the only electron carriers in ETCs that can function without being

tightly bound to a protein
– Its long hydrophobic tail confines ubiquinone to the membrane
• Ubiquinone picks up electrons from NADH dehydrogenase complex or FADH2 and delivers
them to the cytochrome b-c1 complex

Quinones are the only electron carriers in ETCs that can function without being tightly
bound to a protein
– Its long hydrophobic tail ____

confines ubiquinone to the membrane

Ubiquinone picks up electrons from ___ or FADH2 and delivers
them to ——-

NADH dehydrogenase complex, the cytochrome b-c1 complex

quinone slide

what is cytochrome c

an electron carrier in the ETC

cytochrome c is a _ protein

small

cytochrome c contains just over —— aa and is held ——

100, loosely on the outer face of the inner membrane by ionic interaction

what is bound to cytochrome c

heme

the _ atom in the bound heme can carry _

iron atom, a single electron

cytochrome c slide

cytochrome oxidase is a

finely tuned protein machine (protein complex)

Cytochrome oxidase is

a protein complex that receives electrons from cytochrome c and donates these electrons to O2

how many subunits does cytochrome oxidase contain

2, I (one) and II (2)

where is nearly all the oxygen that we breathe used

cytochrome oxidase

As electrons pass through cytochrome oxidase to its bound O2 molecule, they cause

cytochrome oxidase to pump protons across the membrane

At its active site where O2 is bound, cytochrome oxidase contains

a complex of a heme iron atom juxtaposed with a tightly bound copper atom

cytochrome oxidase slide

H+ pumping can be caused by a ___ in a protein pump driven by ——

conformational change, an energetically favorable reaction

Proteins, such as NADH dehydrogenase or cytochrome oxidase, are driven through a cycle of —

3 conformations

conformational change causing proton pumping slide

Chemiosmotic mechanism of ATP synthesis is called

oxidative phosphorylation

Chemiosmotic mechanism of ATP synthesis is called oxidative phosphorylation beacause

it involves both the consumption of O2 and the addition on a phosphate group to ADP to form ATP

oxidative phosphorylation in mitochondria

the electrochemical proton gradient across the inner mitochondrial membrane allows _ to generate ATP from ADP and Pi

ATP synthase

ETC and ATP production slide

the total electrochemical gradient of H+ across the inner mitochondrial membrane is a combination of

a large force due to the membrane potential and a small force due to the H+ concentration graodent

proton motive force:

the role the membrane potential pH that adds to the driving force pulling H+ across the membrane

electrochemical gradient of protons slide

ATP synthase is composed of

a head portion called the F1 ATPase and a transmembrane H+ carrier called the F0 rotor. Both are formed from multile subunits

the F0 rotor is made up of what parts

the H+ carrier (rotor ring), and the central stalk

ATP synthase slide one

is ATP synthase a reversible coupling device

yes

ATP synthase can convert the energy of the _ into _

ATP synthase can convert the energy of the electrochemical proton gradient into chemical-bond energy or vice versa

ATP synthase can either—- or ——

synthesize ATP by harnessing the H+ gradient or pump protons against their electrochemical gradient hydrolyzing ATP

ATP synthase being reversible slide

Overview: Mitochondria and oxidative phosphorylation slide

the electrochemical proton gradient across the inner mitochondrial membrane allow ATP synthase to

generate ATP from ADP and Pi

electrochemical gradient of protons and ATP production

mitochondria and systems within slide

The electrochemical gradient of protons across the inner mitochondrial membrane is used to drive some

coupled transport processes

The electrochemical gradient of protons across the inner mitochondrial membrane is used to drive some coupled transport processes

symport:

antiport:

symport: electrochemical gradient of H+ drives the import of pyruvate and Pi

antiport: pump out ATP and in ADP (ADP-ATP exchange) that depends on a voltage gradient across the membrane (membrane potential), and move 1 negative charge out of the mitochondrion

symport and antiport slide

on glucose oxidation produces about how many ATP

30

in cytosol: 1 NADH →

1.5 ATP (transport of NADH across the inner membrane requires energy)

inside mitochondrial matrix: 1 NADH →

2.5 ATP

where does NADH pass their electrons to in the mitochondrial matrix

the 1st complex, the NADH dehydrogenase

inside mitochondrial matrix:

1 FADH2 →

1.5 ATP

where do FADH2 molecules pass their electrons in the mitochondrial matrix

to the second complex, cytochrome b-c1 complex

Mitochondria maintains a High —/— ratio in cells (— is — times higher than —)

ADP/ATP (ATP is 10 times higher than ADP)

ATP is used as an energy source to

drive energetically unfavorable reactions since ATP hydrolysis is energetically favorable

products slide

what are uncoupling agents

H+ carriers that can insert into the mitochondrial inner membrane