Click this link for a Cellular Respiration Student Learning Guide

Click here for an overview video of oxidative phosphorylation (covered below)

1. Introduction

In the previous tutorials in this series about cellular respiration, we’ve seen how glycolysis, the link reaction, and the Krebs cycle oxidize food so that the mobile electron carriers NAD+ and FAD can be reduced to NADH and FADH2, respectively. 

06_for-every-glucose-w-etc_for-every-glucose-w-etc

NADH and FADHcan be thought of as rechargeable batteries that are fully charged. If you took a01_high-concept-energy-flow-with-nadh-and-fadh2-etc-with-numbers charged up battery and placed it in a flashlight or a radio, then that battery could release a flow of electrical energy that could, in turn, power some work: providing light in the case of the flashlight, or converting radio waves into sound in the case of the radio. In cells, an analogous thing happens. As shown in schematic form below, NADH and FADH2 deliver electrons to the electron transport chain, a series of proteins that are embedded in the inner membrane of the mitochondria.

As electrons flow along the chain, the proteins in the chain do the work of setting up the conditions for ATP creation. Let’s see how this process works.

2. Mitochondria: Structure and Function

ATP synthesis in the mitochondria is a beautiful example of one of biology’s most important ideas: the relationship between structure and function. The quiz below will let you master the key structures involved. Then we’ll move onto the process.

[qwiz qrecord_id=”sciencemusicvideosMeister1961-Mitochondrial Structure for ETC (M10)”] [h]

Interactive Diagrams: Mitochondrial Structure

[i]

Two mitochondria from a mammalian lung
Two mitochondria from a mammalian lung cell

[q labels = “top”]

 

[l]cell exterior

[f*] Excellent!

[fx] No, that’s not correct. Please try again.

[l]cell membrane

[f*] Excellent!

[fx] No. Please try again.

[l]cytoplasm

[f*] Excellent!

[fx] No, that’s not correct. Please try again.

[l]inner membrane

[f*] Good!

[fx] No. Please try again.

[l]intermembrane space

[f*] Good!

[fx] No, that’s not correct. Please try again.

[l]matrix

[f*] Excellent!

[fx] No, that’s not correct. Please try again.

[l]mitochondrion

[f*] Correct!

[fx] No. Please try again.

[l]outer membrane

[f*] Correct!

[fx] No. Please try again.

[q labels = “top”]

Here’s a more realistic depiction of a mitochondrion. You should be able to label all of the parts, with the possible exception of one. ATP Synthase is a protein channel and an enzyme that’s embedded in the mitochondrial membrane. See if you can figure it out as you label the diagram below.

 

 

[l]ATP Synthase

[f*] Excellent!

[fx] No, that’s not correct. Please try again.

[l]chromosome

[f*] Great!

[fx] No. Please try again.

[l]cytoplasm

[f*] Good!

[fx] No, that’s not correct. Please try again.

[l]inner membrane

[f*] Great!

[fx] No, that’s not correct. Please try again.

[l]intermembrane space

[f*] Excellent!

[fx] No. Please try again.

[l]matrix

[f*] Good!

[fx] No. Please try again.

[l]outer membrane

[f*] Great!

[fx] No, that’s not correct. Please try again.

[q] Now we’re going to zoom in on the outer boundary of the mitochondrion. Just focus on the letters (you’ll learn about all the numbered parts later). Which letter is the inner membrane?

[textentry single_char=”true”]
[c*] D

[f] Excellent. “D” is the inner mitochondrial membrane.

[c] Enter word

 

[c] *

[f] No. Here’s a hint: notice that there are two lipid bilayers. If “A” is the cytoplasm, which membrane has to be the inner membrane?

[q]  Which letter is the outer membrane?

[textentry single_char=”true”]
[c*] B

[f] Excellent. “B” is the outer mitochondrial membrane.

[c] Enter word

 

[c] *

[f] No. Here’s a hint: notice that there are two lipid bilayers. If “A” is the cytoplasm, which membrane has to be the outer membrane?

[q]  Which letter indicates the inter-membrane space?

[textentry single_char=”true”]
[c*] C

[f] Excellent. “C” is the inter-membrane space.

[c] Enter word

 

[c] *

[f] No. Here’s a hint: notice that there are two lipid bilayers. Which region must be the space between these two membranes, also known as the “inter-membrane space.”

[q]  Which letter indicates the cytoplasm?

[textentry single_char=”true”]
[c*] A

[f] Excellent. “A” is the cytoplasm.

[c] Enter word

 

[c] *

[f] No. Here’s a hint: notice that there are two lipid bilayers. Which region is outside of the outer membrane (and must, therefore, be the cytoplasm)?

[q]  Which letter indicates the mitochondrial matrix?

[textentry single_char=”true”]
[c*] E

[f] Excellent. “E” is the mitochondrial matrix.

[c] Enter word

 

[c] *

[f] No. Here’s a hint: notice that there are two lipid bilayers. Which region is inside of the inner membrane (and must, therefore, be the matrix, which is the cytoplasm of the mitochondrion)?

[/qwiz]

3. It starts with pumping protons

So, that’s the overall structure. Let’s focus on the electron transport chain, in the inner mitochondrial membrane.

07c_just-the-etc

The chain is a series of protein complexes organized in a sequence in the inner mitochondrial membrane. Organized in this way, you can imagine them as a type of molecular “wire” that allows electrons donated by NADH and FADH2 to flow. The electron flow pathway is shown above at number “2,” with “1” being electron donation by NADH, and “4” being electron donation by FADH2. Each of these donations  are oxidations and result in NADH becoming its oxidized counterpart NAD+, and FADH2 becoming FAD. At the very end of the chain (at “5”), electrons flow to oxygen. As oxygen accepts electrons, it also grabs protons from the matrix. This reduces oxygen to water, the second waste product of cellular respiration.

08_conceptual-etcAn important feature of the electron transport chain is that the electron carriers are organized in terms of electronegativity. Electronegativity is “the tendency to acquire electrons.” As you move along the electron transport chain, each electron carrier has a greater electronegativity than the one before it.  You can see this in the diagram to the left. Inside Complex I you can see the electron carriers FMN and FE.S, which are positioned next to “Q.”  “Q” can pull electrons from FE.S (because “Q” has greater electronegativity).FE.S can, in turn, pull electrons from FMN. You can imagine electrons falling “down” an energy gradient. As they fall, they release energy that can be harvested to do work.

Looking at this diagram, we can see why oxygen is so important in this last phase of cellular respiration. Oxygen is the final electron acceptor in the electron transport chain. Its electronegativity pulls electrons down the chain. Without oxygen, electrons don’t flow. And if electrons don’t flow, the work that makes ATP synthesis possible won’t happen. Life, very quickly, grinds to a halt.

And what is this work? The work is pumping protons from the mitochondrial matrix (shown here below the inner 07c_just-the-etcmembrane) to the intermembrane space (shown above the inner membrane. In this diagram, proton pumps are indicated by the number “3”, and there are three different ones shown: one in Complex I, one in Complex III, and one in Complex IV.

All of these pumps are doing the same thing, and they’re all powered by the same energy source: the flow of electrons along the electron pathway (again, at number “2”).  Note that this is active transport: the pumps are pumping up a concentration gradient, from where protons are less concentrated (in the matrix) to where they’re more concentrated (in the intermembrane space).

4. It ends with making ATP

07_detailed-etcPumping protons from the matrix (E) to the intermembrane space (C) creates an enormous potential energy gradient that the cell harvests to make ATP. This gradient is itself a product of the structure of the mitochondria. Though protons are small, they’re charged, and the phospholipid bilayer is impermeable to charged particles. Consequently once protons are pumped into the intermembrane space, they’re effectively trapped there.

The gradient has several features. First, it’s a diffusion gradient, caused by two forces. Based on what you’ve read above, you know that protons have been pumped into the intermembrane space. At the same time, when oxygen becomes reduced to water at step “5,” protons are being removed from the matrix. That creates a second force: there’s actually a voltage gradient across the inner membrane. The positively charged protons are, in a physical sense, motivated to get out of the positively charged intermembrane space (because like charges repel) and into the more negatively charged matrix (because opposite charges attract).

21_atp-synthase-closeup-w-nicholson-imageThere’s only one way for protons to get back to the matrix, and that’s through a protein channel and an enzyme called ATP synthase. ATP synthase has binding sites for ADP and Pi (inorganic phosphate). When protons diffuse through ATP synthase, their kinetic energy (energy of motion) causes these binding sites to change shape. This catalyzes formation of a bond between ADP and Pi, transforming them into ATP.

Here’s how I describe this process in my Electron Transport Chain music video:

ATP synthase is embedded in the inner membrane
How it works is so cool it’s insane.
It’s got channels for diffusing protons running right through it.
When cells make ATP, well watch how they do it

The matrix side of ATP synthase has binding sites
For ADP and P which come in and bind.
And as ATP synthase lets protons barge through
Their kinetic energy gets put to use.

Like water through a turbine proton movement generates rotation.
Changing synthase’s binding site conformation.
Which catalyzes chemical bond formation.
ADP and P make ATP that energy sensation!

There are a few important biology-vocabulary terms that are connected with this process that you have to know.

  • Chemiosmosis: the generation of ATP by the movement of protons from the intermembrane space across the inner mitochondrial membrane (through ATP synthase) during cellular respiration (adapted from Wikipedia).
  • Oxidative phosphorylation is the process in which ATP is formed as a result of the transfer of electrons from NADH or FADH2 to O2 by a series of electron carriers (adapted from Biochemistry, 5th edition)
  • Proton-motive force is the potential energy stored as a combination of proton and voltage (electrical potential) gradients across a the inner membrane of the mitochondrion (see Wikipedia reference above)

5. Quiz. The Electron Transport Chain

Got it? Start with the following quiz.

[qwiz random = “true” qrecord_id=”sciencemusicvideosMeister1961-Electron Transport Chain Quiz (M10)”]

[h]Quiz: The electron transport chain

[i]

[q]In the diagram below, which number represents the part where you’d find ATP synthase?


[textentry single_char=”true”]
[c*]6
[f] Yes, “6” is the inner mitochondrial membrane, which is where ATP synthase is located.
[c]*
[f]No. Here’s a hint. ATP synthase generates ATP as protons flow from the intermembrane space to the matrix. Where would ATP synthase have to be located in order to allow for this?
[!]++++Question 2+,electron transport chain++[/!!!]

[q]In the diagram below, which number represents the part where you’d find the electron transport chain?

[textentry single_char=”true”]
[c*]6
[f] Yes, “6” is the inner mitochondrial membrane, which is where the electron transport chain is located.
[c]*
[f]No. Here’s a hint. The electron transport chain pumps protons from the matrix to the intermembrane space. Where would it have to be located in order to allow for this?
[!]++++Question 3+ where are protons pump to++[/!!!]

[q]In the diagram below, which number represents the area that protons get pumped into?

[textentry single_char=”true”]
[c*]7
[f] Yes. “7” is the intermembrane space, which is where protons get pumped into in order to create a concentration gradient for synthesizing ATP.
[c]*
[f]No. Here’s a hint. The protons start in the matrix. Where could they go to in order to create a concentration gradient for synthesizing ATP?
[!]++++Question 4+ where do protons flow to[/!!!]
[q]In the diagram below, which number represents the area that protons flow to as they flow through ATP synthase, making ATP?

[textentry single_char=”true”]
[c*]5
[f] Yes. “5” is the matrix, which is where protons flow to as they flow from the intermembrane space, through ATP synthase, into the matrix.
[c]*
[f]No. Here’s a hint. The protons have been pumped to the intermembrane space. The outer membrane is impermeable to protons. So is the inner membrane, except for the ATP synthase channel. If the protons flow through ATP synthase, where are they going to wind up?
[!]++++Question 5+ where is NADH oxidized[/!!!]
[q]In the diagram below, where is NADH oxidized?

[textentry single_char=”true”]
[c*]6
[f] Yes. “6” is the inner membrane, which is where NADH is oxidized, giving up its electrons to the electron transport chain.
[c]*
[f]No. Here’s a hint. When NADH is oxidized, it gives up energetic electrons that flow along the electron transport chain. Where is the electron transport chain located?
[!]++++Question 5+ where is NAD+ reduced [/!!!]
[q]Within the mitochondria, where is NAD+ reduced to NADH?

[textentry single_char=”true”]
[c*]5
[f] Yes. “5” is the matrix. During both the link reaction and the Krebs cycle, NAD+ gets reduced to NADH, and both these processes occur in the mitochondrial matrix.
[c]*
[f]No. Here’s a hint. Two processes within the mitochondria reduce NAD+ to NADH. These are the link reaction and the Krebs cycle. Where within the mitochondria do these processes occur?
[!]++++Question 6+ [/!!!]
[q]Which number or letter below represents the electron transport chain?

[textentry single_char=”true”]
[c*]2
[f] Yes. “2” represents the electron transport chain.
[c]*
[f]No. Here’s a hint. Electrons are donated by NADH and FADH2. Which part of the diagram could represent the flow of these electrons through the inner mitochondrial membrane?
[!]++++Question 7+ [/!!!]
[q]Which number or letter below shows active transport?
[textentry single_char=”true”]
[c*]3
[f] Yes. “3” represents the active transport of protons from the matrix (where they’re in lower concentration) to the intermembrane space (where they’re in higher concentration)
[c]*
[f]No. Here’s a hint. Active transport is up a concentration gradient. Examine the matrix and the intermembrane space. Where do you see something getting pumped from lower concentration to higher concentration?
[!]++++Question 8+ [/!!!]
[q]Which number or letter below shows ATP synthase?
[textentry single_char=”true”]
[c*]6
[f] Yes. “6” represents ATP synthase.
[c]*
[f]No. Here’s a hint. ATP synthase is both an enzyme that makes ATP, and an proton channel. Which part of the diagram could possible be both of these things?
[!]++++Question 9+ [/!!!]
[q]Which letter or number represents a region that would have the lowest pH?

[textentry single_char=”true”]
[c*]C
[f] Yes. “C” is the intermembrane space. The accumulation of protons in this area would give it the lowest pH of any area within the mitochondrion.
[c]*
[f]No. Here’s a hint. pH is a measure of hydrogen ion concentration. Which region has a lot of hydrogen ions (or protons), and would therefore have a lowered pH?
[!]++++Question 10+ [/!!!]
[q]Which letter or number best represents “proton-motive force?”

[textentry single_char=”true”]
[c*]6
[f] Yes. “6” shows protons diffusing from the intermembrane space, through ATP synthase, into the matrix. This diffusion drives the synthesis of ATP from ADP and Pi, and the force that makes this possible is “proton motive force.”
[c]*
[f]No. Here’s a hint. Proton-motive force is the force that drives ATP synthesis as protons diffuse from the intermembrane space into the matrix. Which number shows this happening?
[!]++++Question 11+ [/!!!]
[q]Which letter or number shows a process that does not involve pumping and which lowers the proton concentration in the matrix?

[textentry single_char=”true”]
[c*]5
[f] Yes. “5” shows oxygen absorbing electrons from the electron transport chain and protons (H+) from the matrix. This lowers the proton concentration in the matrix, increasing the concentration gradient that drives ATP synthesis as protons diffuse through the ATP synthase.
[c]*
[f]No. Look closely at the diagram. There’s only one place where protons are being absorbed by the matrix, and it’s at the very end of the electron transport chain (it’s not “3,” which involves pumping).
[!]++++Question 12+ [/!!!]
[q]At numbers 1 and 4, mobile electron carriers are being

[c*]oxidized [c]reduced [c]phosphorylated
[f] Yes. As NADH and FADH2 bring electrons to the electron transport chain, they become oxidized to NAD+ and FAD.
[f]No. Reduction is the gain of electrons. For example, when NAD+ become NADH, that’s a reduction.
[f]No. Phosphorylation is the gain of a phosphate group. That’s not what’s happening here.
[!]++++Question 13+ [/!!!]
[q]What’s happening at “6” in the diagram below is

[c]oxidation
[c]reduction
[c]substrate level phosphorylation
[c*]oxidative phosphorylation
[f]No. Oxidation is the loss of electrons. Look closely at what’s happening at “6.” Notice that it involves a phosphate (which is a big hint).
[f]No. Reduction is the gain of electrons. Look closely at what’s happening at “6.” Notice that it involves a phosphate (which is a big hint).
[f]No. Substrate level phosphorylation involve enzymes that transfer a phosphate from an organic substrate an place it onto ADP, making ATP. “6” is definitely a phosphorylation, but it’s not “substrate level”
[f]Yes. The phosphorylation that happens at ATP synthase is called “oxidative phosphorylation,” because it requires the presence of oxygen to power the electron transport chain.
[!]++++Question 14+ [/!!!]
[q]Which letter or number shows where substrate level phosphorylations are occurring within the mitochondria?

[textentry single_char=”true”]
[c*]E
[f] Yes. “E” is the matrix. Within the matrix, the Krebs cycle carries out one substrate phosphorylation for each acetyl group that is brought into the cycle.
[c]*
[f]No. Here’s a hint. Substrate level phosphorylations occur during the Krebs cycle. Where does the Krebs cycle occur?
[!]++++Question 15+[/!!!]
[q]Of the following protein complexes, which must have the most electronegative electron carriers?

[c]I [c]II [c]III [c*]IV
[f] No. The electron carriers in the electron transport chain are organized in order of increasing electronegativity. Complex I is the least electronegative.
[f] No. The electron carriers in the electron transport chain are organized in order of increasing electronegativity. Complex I is the least electronegative. Which one would be the most?
[f] No. The electron carriers in the electron transport chain are organized in order of increasing electronegativity. Complex I is the least electronegative. Which one would be the most?
[f] Yes. The electron carriers in the electron transport chain are organized in order of increasing electronegativity. Complex I is the least electronegative, and complex IV is the most electronegative.

[/qwiz]

6. Electron Transport Chain: Interactive Lyrics

Working with the lyrics is a great way to learn the details of the electron transport chain and chemiosmosis.

[qwiz qrecord_id=”sciencemusicvideosMeister1961-Electron Transport Chain Fill-in-the-Blanks (M10)”]

[h]The Electron Transport Chain Song: Interactive Lyrics

[i]

[q labels = “top”]

Welcome to this story about cell _______.
The goal is explaining how cells make ATP
It happens in the ____________ which you can think of
As the cell’s energy factory

 

Mitochondria are double-membraned organelles,
An inner membrane and an outer one as well
The mitochondrial _______ is the fluid inside
It’s where reactions like ______ cycle reside

[l]energy

[fx] No, that’s not correct. Please try again.

[f*] Correct!

[l]mitochondria

[fx] No. Please try again.

[f*] Good!

[l]matrix

[fx] No, that’s not correct. Please try again.

[f*] Excellent!

[l]Krebs

[fx] No, that’s not correct. Please try again.

[f*] Excellent!

[!!!!] SECOND VERSE[/!!!!]

[q labels = “top”]
__________ and Krebs make NADH
and FADH2 from energy in food
These ________ carriers make their way
From the matrix to the inner membrane.

And that’s where you find the electron transport chain
It’s a series of _________ embedded in the membrane,
Which take the electron carrier’s electrons
And uses their energy for pumping ________

[l]electron

[fx] No. Please try again.

[f*] Excellent!

[l]enzymes

[fx] No. Please try again.

[f*] Good!

[l]glycolysis

[fx] No. Please try again.

[f*] Excellent!

[l]protons

[fx] No, that’s not correct. Please try again.

[f*] Good!

[!!!!!]CHORUS: Just put in two or three labels to drag. [/!!!!!]

[q labels = “top”]

The mitochondrial electron transport chain
Uses electron energy for pumping protons
From the mitochondrial ________ to the intermembrane space
Increasing proton concentration in that place,
The only way the protons can escape
Is through a channel and an enzyme, ATP __________.
Which uses diffusing protons’ kinetic energy
To make ATP, from ______ and P

[l]ADP

[fx] No, that’s not correct. Please try again.

[f*] Correct!

[l]matrix

[fx] No. Please try again.

[f*] Great!

[l]synthase

[fx] No, that’s not correct. Please try again.

[f*] Excellent!

[!!!] start of next verse[/!!!]

[q labels = “top”]
The chain is a series of _________ in a row
Each accepts __________, then lets them go
To the next carrier in this transport chain.
It’s kind of organized like a bucket brigade

 

What drives electrons down this enzymatic series
Is the growing level of each carrier’s _______________
And to _________ electrons ultimately fall
It’s the most electronegative of them all.

[l]electronegativity

[fx] No, that’s not correct. Please try again.

[f*] Correct!

[l]electrons

[fx] No. Please try again.

[f*] Correct!

[l]enzymes

[fx] No, that’s not correct. Please try again.

[f*] Good!

[l]oxygen

[fx] No. Please try again.

[f*] Excellent!

[q labels = “top”]

It’s NADH that starts this run
Donating electrons to Complex number I
This powers ________ transport as protons are displaced.
And get pumped from the matrix to the _____________ space

 

From Complex I electrons flow to
___________, also known as “Q”
Which floats through the inner membrane happily
And brings its electrons to __________.

[l]active

[fx] No, that’s not correct. Please try again.

[f*] Great!

[l]Complex III

[fx] No, that’s not correct. Please try again.

[f*] Good!

[l]intermembrane

[fx] No, that’s not correct. Please try again.

[f*] Great!

[l]Ubiquinone

[fx] No. Please try again.

[f*] Great!

[q labels = “top”]

And you can guess the function of Complex III .
It’s another proton _______ using _________ energy
Protons jam up in that intermembrane compartment
Like a hundred people in a one bedroom apartment!

CHORUS

 

Complex II is for FADH2
Which donates electrons, which then get passed to ____
Which once again passes them to Complex III
Which pumps _________ using electron energy

[l]electron

[fx] No. Please try again.

[f*] Good!

[l]protons

[fx] No, that’s not correct. Please try again.

[f*] Excellent!

[l]pump

[fx] No. Please try again.

[f*] Great!

[l]Q

[fx] No. Please try again.

[f*] Good!

[q labels = “top”]

From Complex III the electrons proceed
To another mobile carrier, ___________ C
Which donates the electrons to Complex IV
Another proton pump, could you ask for more?

 

After Complex IV __________ flow,
To oxygen which is ever so
______________ it pulls electrons down the _______,
Keeping them moving like the cars of a train.

[l]chain

[fx] No. Please try again.

[f*] Great!

[l]Cytochrome

[fx] No, that’s not correct. Please try again.

[f*] Great!

[l]electronegative

[fx] No. Please try again.

[f*] Good!

[l]electrons

[fx] No, that’s not correct. Please try again.

[f*] Excellent!

[q labels = “top”]

And as O2 does this electron grabbing trick,
It also grabs protons from the matrix.
They all combine to form ______
Electron __________ chain, watch it go!

CHORUS

Now all these protons in the intermembrane space
Are trapped they can’t get out of that place
‘Cause protons are _________ and could never get through
A ____________ bilayer, they can’t diffuse

[l]charged

[fx] No. Please try again.

[f*] Great!

[l]H2O

[fx] No, that’s not correct. Please try again.

[f*] Good!

[l]phospholipid

[fx] No. Please try again.

[f*] Good!

[l]transport

[fx] No, that’s not correct. Please try again.

[f*] Correct!

[q labels = “top”]

But like all particles, they’re dying to go
From where their concentration’s _______ to where it’s low.
Stuck in the intermembrane space they’re frustrated.
To diffuse to the ________, they’re highly motivated.

 

And this __________ been made steeper by O2
Which absorbs protons from the matrix stew,
So from proton pumping, and oxygen’s actions.
Add another force, ______________ attraction!

[l]electrochemical

[fx] No, that’s not correct. Please try again.

[f*] Correct!

[l]gradient’s

[fx] No. Please try again.

[f*] Excellent!

[l]high

[fx] No, that’s not correct. Please try again.

[f*] Excellent!

[l]matrix

[fx] No. Please try again.

[f*] Great!

[q labels = “top”]

Think of all those trapped protons, each one’s _________.
The matrix, in comparison is negative.
Opposites attract, so the protons are dying
To get to matrix, oh how they’re trying!

There’s only one _________ that lets the protons pass,
And they use it like high school students busting out of class,
It’s a channel and an _________, it’s ATP __________
The closer in this game, an energy ace

 

[l]channel

[fx] No, that’s not correct. Please try again.

[f*] Great!

[l]enzyme

[fx] No. Please try again.

[f*] Excellent!

[l]positive

[fx] No, that’s not correct. Please try again.

[f*] Great!

[l]synthase

[fx] No. Please try again.

[f*] Correct!

[q labels = “top”]

ATP synthase is embedded in the _______ membrane
How it works is so cool it’s insane.
It’s got channels for diffusing protons running right through it.
When cells make ATP, well watch how they do it

 

 

 

The matrix side of ATP synthase has binding sites
For ADP and _____ which come in and bind.
And as ATP synthase lets protons barge through
Their ________ energy gets put to use.

 

Like water through a turbine ________ movement generates _________.
Changing synthase’s binding site conformation.
Which catalyzes chemical bond formation.
ADP and P make _______ that energy sensation!

 

 

[l]ATP

[fx] No. Please try again.

[f*] Great!

[l]inner

[fx] No. Please try again.

[f*] Good!

[l]kinetic

[fx] No. Please try again.

[f*] Correct!

[l]P

[fx] No, that’s not correct. Please try again.

[f*] Excellent!

[l]proton

[fx] No. Please try again.

[f*] Great!

[l]rotation

[fx] No, that’s not correct. Please try again.

[f*] Correct!

[x]

[restart]

[/qwiz]

7. Electron Transport Chain Fill-in-the-Blanks Quiz

[qwiz random = “true” qrecord_id=”sciencemusicvideosMeister1961-Electron Transport Chain Interactive Lyrics (M10)”]

[h]Electron Transport Chain Fill-in-the-Blanks

[i]

[!!!!!] CARD NUMBER 1 [/!!!!!]

[q]Most of the cell’s __________ is made in the mitochondria.

[hangman]

[c]ATP

[f]Yes! Most of the cell’s ATP is made in the mitochondria.

[!!!!!] CARD NUMBER 2 [/!!!!!]

[q]The enzyme rich fluid inside the mitochondrial inner membrane is the __________.

[hangman]

[c]matrix

[f]Correct! The enzyme rich fluid inside the mitochondrial inner membrane is the matrix.

[!!!!!] CARD NUMBER 3 [/!!!!!]

[q]The mitochondrial electron transport chain uses energy in electrons in order to pump __________ into the intermembrane space.

[hangman]

[c]protons

[f]Great! The mitochondrial electron transport chain uses energy in electrons in order to pump protons into the intermembrane space.

[!!!!!] CARD NUMBER 4 [/!!!!!]

[q]The ETC makes ATP when __________ diffuse through the ATP synthase channel from the intermembrane space back to the matrix.

[hangman]

[c]protons

[f]Good job! The ETC makes ATP when protons diffuse through the ATP synthase channel from the intermembrane space back to the matrix.

[!!!!!] CARD NUMBER 6 [/!!!!!]

[q]When protons diffuse from the intermembrane space to the matrix, their kinetic energy is what drives ATP __________.

[hangman]

[c]synthesis

[f]Fantastic! When protons diffuse from the intermembrane space to the matrix, their kinetic energy is what drives ATP synthesis.

[!!!!!] CARD NUMBER 7 [/!!!!!]

[q]The last electron acceptor in the mitochondrial electron transport chain is __________.

[hangman]

[c]oxygen

[f]Awesome! The ultimate electron acceptor in the mitochondrial electron transport chain is oxygen.

[!!!!!] CARD NUMBER 8 [/!!!!!]

[q]Enzyme Complexes 1, 3, and 4 are all __________ pumps.

[hangman]

[c]proton

[f]Genius! Enzyme Complexes 1, 3, and 4 are all proton pumps.

[!!!!!] CARD NUMBER 9 [/!!!!!]

[q]The electrons dropped off by __________ have less energy than those dropped off by NADH, and thereby power the pumping of fewer protons (note: don’t worry about typing subscripts)

[hangman]

[c]FADH2

[f]Correct! The electrons dropped off by FADH2 have less energy than those dropped off by NADH, and thereby power the pumping of fewer protons.

[!!!!!] CARD NUMBER 10 [/!!!!!]

[q]As __________ accepts electrons from the ETC and soaks up protons from the matrix, it creates water.

[hangman]

[c]oxygen

[f]Yes! As oxygen accepts electrons from the ETC and soaks up protons from the matrix, it creates water.

[!!!!!] CARD NUMBER 11 [/!!!!!]

[q]The protons in the intermembrane space can’t diffuse through the  __________ in the inner membrane.

[hangman]

[c]phospholipids

[f]Good job!The protons in the intermembrane space can’t diffuse through the  phospholipids in the inner membrane.

[!!!!!] CARD NUMBER 12 [/!!!!!]

[q]Protons in the __________ “want” to diffuse back to the matrix.

[hangman]

[c]intermembrane space

[f]Great! Protons in the intermembrane space “want” to diffuse back to the matrix.

 

[!!!!!] CARD NUMBER 14 [/!!!!!]

[q]The only way protons can get from the intermembrane space to the matrix is through the ____ ______ channel.

[hangman]

[c]ATP synthase

[f]Great! The only way protons can get from the intermembrane space to the matrix is through the ATP synthase channel.

[!!!!!] CARD NUMBER 15 [/!!!!!]

[q]During ATP synthesis, ______ and Pi (inorganic phosphate) bind at binding sites on the matrix side of ATP synthase.

[hangman]

[c]ADP

[f]Correct! During ATP synthesis, ADP and Pi (inorganic phosphate) bind at binding sites on the matrix side of ATP synthase.

[!!!!!] CARD NUMBER 16 [/!!!!!]

[q]NADH and FADH2 are _______ __________.

[hangman]

[c]electron carriers

[f]Correct! NADH and FADH2 are electron carriers.

[!!!!!] CARD NUMBER 17 [/!!!!!]

[q]The mitochondrial electron transport chain is a series of enzymes embedded in the __________ mitochondrial membrane.

[hangman]

[c]inner

[f]Great! The mitochondrial electron transport chain is a series of enzymes embedded in the inner mitochondrial membrane.

[!!!!!] CARD NUMBER 18 [/!!!!!]

[q]The ETC makes ATP when protons diffuse through the ATP __________ channel from the intermembrane space back to the matrix.

[hangman]

[c]synthase

[f]Correct! The ETC makes ATP when protons diffuse through the ATP synthase channel from the intermembrane space back to the matrix.

[!!!!!] CARD NUMBER 19 [/!!!!!]

[q]When protons diffuse from the intermembrane space to the __________, their kinetic energy is what drives ATP synthesis.

[hangman]

[c]matrix

[f]Yes! When protons diffuse from the intermembrane space to the matrix, their kinetic energy is what drives ATP synthesis.

[!!!!!] CARD NUMBER 20 [/!!!!!]

[q]In the electron transport chain, each electron carrier is more __________ than the one that preceded it.

[hangman]

[c]electronegative

[f]Perfect! In the electron transport chain, each electron carrier is more electronegative than the one that preceded it.

[!!!!!] CARD NUMBER 21 [/!!!!!]

[q]NADH brings _________ to the top of the mitochondrial electron transport chain.

[hangman]

[c]electrons

[f]Great! NADH brings electrons to the top of the mitochondrial electron transport chain.

[!!!!!] CARD NUMBER 22 [/!!!!!]

[q]In the mitochondrial electron transport chain, proton pumps in the inner mitochondrial membrane pump protons from the __________ to the intermembrane space.

[hangman]

[c]matrix

[f]Correct! In the mitochondrial electron transport chain, proton pumps in the inner mitochondrial membrane pump protons from the matrix to the intermembrane space.

[!!!!!] CARD NUMBER 23 [/!!!!!]

[q]The electrons dropped off by FADH2 have less energy than those dropped off by __________, and thereby power the pumping of fewer protons.

[hangman]

[c]NADH

[f]Absolutely! The electrons dropped off by FADH2 have less energy than those dropped off by NADH, and thereby power the pumping of fewer protons.

[!!!!!] CARD NUMBER 24 [/!!!!!]

[q]During ATP synthesis, diffusing __________provide kinetic energy to transform ADP and P into ATP.

[hangman]

[c]protons

[f]Fabulous! During ATP synthesis, diffusing protons provide kinetic energy to transform ADP and Pi into ATP.

[!!!!!] CARD NUMBER 25 [/!!!!!]

[q]Mitochondria have a __________ membrane.

[hangman]

[c]double

[f]Genius! Mitochondria have a double membrane.

[!!!!!] CARD NUMBER 26 [/!!!!!]

[q]__________ pumping by the ETC creates a diffusion gradient where protons are much more concentrated in the intermembrane space than they are in the matrix.

[hangman]

[c]proton

[f]Correct! Proton pumping by the ETC creates a diffusion gradient where protons are much more concentrated in the intermembrane space than they are in the matrix.

 

[!!!!!] CARD NUMBER 29 [/!!!!!]

[q]Kinetic energy from __________ protons catalyzes chemical bond formation to create ATP from ADP and Pi.

[hangman]

[c]diffusing

[f]Great! Kinetic energy from diffusing protons catalyzes chemical bond formation to create ATP from ADP and P.

[x]

[restart]
[/qwiz]

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