Cellular Respiration
Lesson One
Cellular Respiration
 The overall equation for cellular respiration can be misleading if you
consider its true purpose
o To __________ stored energy for cells to use
 A more accurate representation would be something like this:
 Remember that Photosynthesis and Cellular Respiration are __________
 The ________ that comes out of cellular respiration is in the form of ___
o Remember ATP? The small form of energy that our cells can use for
everything
 Active transport, cell movement, cell processes like building
molecules & breaking molecules, muscle contraction, etc.
o ATP keeps your cells (you) alive
 There are two types of cellular respiration
o __________ cellular respiration
 Your cells do this when they have _________
o ___________ cellular respiration
 Your cells do this when they _____ have enough oxygen
o All cells do cellular respiration to keep alive
 Animal cells can do ____________ but not enough to
sustain life
 Some bacteria and fungi can do either one and stay alive
(________ anaerobes) but there are some who cannot live
with oxygen (________ anaerobes)
Aerobic Cellular Respiration
 There are 4 steps to Aerobic cellular Respiration and they all
contribute in 1 or 2 ways to making _____
 By the end, we should have a total of approx. ___ ATP
 Steps and their location within the cell
o Step 1: ______________ (cytoplasm)
o Step 2: _____________________ (mitochondrial matrix)
o Step 3: _______________ (mitochondrial matrix)
o Step 4: ___________________ (inner Mt membrane)
 Parts of the mitochondria (Mt)
o You might remember that it is the “___________” of the
cell, so most of the ATP is made within it.
 For each step we learn, our focus is “How is it making ATP?”
 There are two ways that Aerobic cellular respiration produces ATP
o _______________
 Which you already saw in Photosynthesis
o _______________________________________
 Which is new but you don’t need to know in detail
 Chemiosmosis will take place in the Electron Transport Chain step (just
like with _________________)
o The energized __________ will create a _____ concentration
gradient which will lead to diffusion of _____ through the ATP
Synthase Complex
o This will produce _____ out of our total 36 ATP
 Substrate-Level Phosphorylation means taking a ___________ from the
“substrate” and adding it to ADP to make ATP
 A substrate is the molecule we are _________ down
 In the beginning, this molecule is glucose
o This will happen in the Glycolysis and Krebs Cycle steps
o There is some chemistry magic involved in this that we won’t be
learning in Bio 20
o This will produce 4 (2 each) out of our total 36 ATP
Step 1: Glycolysis
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Glycolysis literally means “ _______ _________”
This is where the ________ from photosynthesis) begins to break down
This step takes place in the _____________ of the cell.
The glucose is split into two molecules called ____________ or pyruvic
acids (same thing)
 When glucose (________) is split into 2 pyruvates, some products are
made:
o The glucose is _________ by 2 NAD+ making 2 NADH
 NAD+ is similar to NADP+ from photosynthesis; it is an
________ _________ and therefore another form of
stored energy
 These 2_____ will be important for making ATP through
chemiosmosis in the last step
o 4 ADP molecules are phosphorylated by the glucose to make 4 ____
molecules
 ADP and P are floating around in the cell just waiting to be
________ together
 Energy from the _______ is used to bond them together
without the ATP Synthase Complex
 This is called Substrate-Level Phosphorylation (____)
 This breakup of glucose will also require some energy (____) to get started
 Although glycolysis will produce 4 ATP, it also requires _____ that will be
used up
 This is why we say there is a ____ (overall/total) gain of 2 ATP from this
step
 -2 ATP+ 4 ATP = 2 ATP
 Remember the purpose is to ___________ the energy stored in the
glucose, so let’s see where it is now
o Some left with the e- and H+ into _______
 This will be used in the ______ to make more ATP
o Some left with the bonding of ____ and ___ into 2 ATP
o The rest is still stored within the bonds of the 2 pyruvate molecules
Step 2: Pyruvate Oxidation
 The 2 pyruvate molecules go into ___________________ in order to be
further broken down
 Sometimes this step is combined with the next step (Krebs Cycle) and you
will see cellular respiration described as a 3 step process
 We will consider it a separate step
 The _________ is split into two molecules called _____________
 When pyruvates are split into Acetyl CoA, some products are made:
o The pyruvate is ____________ by NAD+ to make NADH
 2 pyruvates = 2 NADH made
o A ________ (and oxygens) leave making ____
 2 pyruvates = 2 CO2
o Coenzyme A attaches making the compound into Acetyl Co A
 Remember the purpose is to ___________ the energy stored in the
glucose, so let’s see where it is now
o Some left with the e- and H+ into _______
 This will be used in the ______ to make more ATP
o Some is still stored within the bonds of the 2_____
 Wasted energy
o The rest is still stored within the bonds of the 2 _______ molecules
o No ATP is directly made at this step
Step 3: Krebs Cycle
 The Acetyl CoA enters the cycle and is ____________ broken apart
 When Acetyl CoA breaks down, some products are made:
o __________ are produced (3 from each cycle
 6 NAD+ are ___________ by gaining e- and H+ from Acetyl
CoA
o __________ are produced (1 from each cycle)
 Also an _______________ like NADH
 2 FAD are reduced by __________ e- and H+ from Acetyl
CoA
o ________ are produced (2 from each cycle)
 The carbons and oxygens are from the original ________
 The compound is unstable after losing the e- and H+ so it also
loses some C and O (chemistry magic)
o ______ are produced (1 from each cycle)
 ________________________________
 The energy from breaking down Acetyl CoA is used to bond
more free floating ADP and P together to form _____.
 Again this happens without the use of the ATP Synthase
Complex
 All of the glucose energy has been transferred into smaller chunks at this
point
 Remember the purpose is to ___________ the energy stored in the
glucose, so let’s see where it is now
o Some left with the e- and H+ into _______
o Some left with the e- and H+ into _______
o Some left with the bonding of ____ and ___ into 2 ATP
o Some is still stored in the bonds of the _____
 But we’ve only made _____ total so far…not very many for 1 glucose
molecule
Step 4: ETC
 The ______ and _______ bring the e- and H+ to the Electron Transport
Chain
 When e- go through the ETC, some products are made:
o 32 ATP
 Through _____________
 The electron carriers drop off the e- and H+, turning back into
________ and _______
 These now go ______ to the other 3 steps to pick up
more e- and ___ and keeps the process going
 The e- go into the ETC and H+ are immediately sent to the
_______________ space
 Space between the inner and outer membrane
 The e- energy (originally from _______) is used to pump
more free floating H+ into the intermembrane space creating a
______________ ___________
 The H+ _______ into the ______ through the ATP
Synthase Complex
 Making ________ per one molecule of glucose
o 6 water molecules
 After the e- lose all their _______ in the ETC they join up
with free floating ___ and ___ to make H2O
 The oxygen comes into the Mitochondria from the air
you breather
 This is it! This is why you need Oxygen to live!
o The _______ is required in your body so that it can act as final
electron ___________ at the end of ETC and make water
 Without O2 there to take the e-, the ETC can’t run
 And you run out of ATP (because there are no carriers
taking the e- to the ETC) and your cells die.
Aerobic Cellular Respiration
 Recap of the steps and their products (all you really need to know)
 Step 1 Glycolysis (___________)
o ________, ______
 Step 2 Pyruvate Oxidation (__________)
o _______, ______
 Step 3 Krebs Cycle (____________)
o _______, _______, ____, _____
 Step 4 ETC (____________________________)
o _____, ______
 How does this compare to our equation?
C6H12O6 + 6O2
6CO2 + 6H2O + ATP
 Why aren’t the electron carriers in the equation?
o The electron carriers are not ________ products in the reaction
o They are just ____________ products
o The ____ changes back and for from NADH (ditto for FADH2) as it
gains electrons in one step and then loses them in another step. Then
it goes back and gains them again in the first step. Its job is never
finished.
Lesson 1 Formative
Pg 212 #1,3
pg 220 #2, 5(a-d), 6
pg 215 #1
Hand in pg 219 #6 and pg 220 # 5
pg 219 #4,5,6
Lesson 2
Anaerobic Cellular Respiration
 We already looked at what happens when our cells don’t get enough O2
(they die because of the buildup at the ETC) but what if there is a
temporary shortage?
 Even under limited oxygen availability, cells will do ____________
o Producing ___________, _______, and ________
 The pyruvates are poison to the cells
 Yay ATP!
 The NADH can’t be used in the ETC
 The poison ____________ can’t stay there, so they undergo a process
called ________________.
 Many types of cells do fermentation so there are different kinds
 Animal cells perform _________ ______ fermentation
o This takes the pyruvate and NADH and turns them into lactic acid
 This does not give our cells extra energy
 Yeast (a ______) and some bacteria do _________ fermentation
o This takes the pyruvate and NADH and turns them into
_________ and _____
 This does not give cells extra energy but can be useful in other
ways
Lactic Acid Fermentation
 The two steps of Lactic Acid Fermentation take place within the
____________ of the cell and produce very little ATP
o Glycolysis
 ______
o Fermentation
 ______
 Overall Anaerobic cellular respiration supplies our cells with very little
energy (_______) vs. Aerobic cellular respiration (________)
Alcohol Fermentation
 The products of ________ fermentation are much more useful to us that
the lactic acid that our own cells make
 We can use the ethanol part to make alcoholic beverages (fermentation of a
plant product like grapes or corn, is how wine, beer, whisky, vodka, etc.
are made)
 We can use the CO2 part to make dough ______. That’s why yeast is
added to bread; it ferments the _______ making alcohol and CO2. The
alcohol evaporates right away as it’s cooked and the CO2 makes it light and
fluffy
 Other everyday products are also the result of fermentation
o __________ (bacteria ferment milk)
o __________ (different bacteria ferment milk)
o __________ (fermented cucumbers)
o ___________ (fermented cacao fruits)
o __________ (fermented wine)
o ___________ (fermented cabbage)
Lesson 2 Formative
Pg 222 #1
Pg 226 #4,5
Pg 228 #1
Pg 232 #1-6, 9-18
Hand in pg 226 #4, pg 228 #1, pg 232 #1-6, 9,10, 15-18