Transcript Cellular Respiration and Photosynthesis

Intro to Metabolism Wrap-up
1.
2.
3.
4.
5.
Answer these questions in your notes – you
should discuss with your colleagues!
Why do we say that ATP “couples” reactions?
What are enzymes, and how do they affect
chemical reactions?
What type of biological molecule are enzymes,
and what are the levels of their structure?
What factors (environmental and otherwise)
affect the rates of enzyme-catalyzed
reactions? (there are SEVERAL!)
Why would boiling an enzyme probably
destroy its activity?
Agenda and Business
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Intro to Metabolism Recap
Big Picture – Energy Production and Storage
Connection – Cellular Respiration and Photosynthesis
Big Picture – Cellular Respiration
Enzyme Lab due Friday – does not NEED to be typed but
you can if you want (you already should have title,
purpose, materials, procedures, and data tables – you
need to include graphs for part I and part II and a
conclusion about why the rate decreases over time
[remember toothpickase???] and a conclusion/analysis
about pH and enzyme activity [what was the optimal pH?
What would you guess about the pH of the environment
the turnips usually grow in?)
Energy Production and Storage
The energy timeline
 Cellular cash
 Doesn’t

Checking account
 More

last long… quickly hydrolyzed
stable, can convert to “cash” easily
Savings account
 More
stable yet, must be broken down before
it can be converted to “cash”
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Retirement fund
 Most
stable, longest term energy storage
Connection:
Cellular Respiration
and Photosynthesis
What can you say
about the reactants
and products of
each reaction?
What about the
energy of each
reaction?
Big Picture: Cellular Respiration
What is the whole point of cellular respiration?
Cellular Respiration
and Photosynthesis
Jammin’ to ATP
Glucose, Glucose
 Oxidative Phosphorylation
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Check out www.science-groove.org/
Glucose,
Glucose
 Glucose -- ah, sugar sugar -- | You are my favorite fuel |
From the blood-borne substrate pool. | Glucose -monosaccharide sugar -- | You're sweeter than a woman's
kiss | 'Cause I need you for glycolysis. | I just can't believe
the way my muscles take you in. | (For you, they'll open the
door.) | All it takes is a little bit of insulin | (To upregulate
GLUT4). | Ah, glucose -- ah, sugar sugar -- | You help me
make ATP | When my predators are chasing me. | Ah,
glucose -- you're an aldehyde sugar, | And you're sweeter
than a woman's kiss | 'Cause I need you for glycolysis. | I just
can't believe the way my muscles break you down. | (My
glycogen is almost gone.) | A few more seconds and I'll be
rigor mortis-bound. | (Acidosis done me wrong.) | Your sweet
is turning sour, baby. | I'm losing all my power, baby. | I'm
gonna make your muscles ache. | No, no, no! | I'm swimming
in lactate, baby. | Yes, I'm swimming in lactate, baby. | Now
I'm drowning in lactate, baby. | I'm gonna make your muscles
ache. | No, no, no! | I'm drowning in lactate, baby. | Ah,
glucose -- ah, sugar sugar -- | I used you up and you left me
flat; | Now I'll have to get my kicks from fat. | Oh, glucose,
glucose, sugar, sugar, | The honeymoon is over now.
Enzyme Quiz
Recap
1.
What is an autotroph?
2.
What is a heterotroph?
3.
What do all food chains start with?
4.
What do glucose, glycogen, and starch have
in common?
5.
Why do we eat and breathe? (don’t you dare
say “to live”)
Endosymbiosis and Energy Recap
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What does endosymbiosis have to do with energy?
Why did mitochondria evolve when they did?
Chapter 9 – Cellular Respiration:
Harvesting Chemical Energy
YOU MUST KNOW
The difference between fermentation and cellular
respiration.
The role of glycolysis in oxidizing glucose to two molecules
of pyruvate.
The process that brings pyruvate from the cytosol into
the mitochondria and introduces it into the citric acid
cycle.
How the process of chemiosmosis utilizes the electrons
from NADH and FADH2 to produce ATP.
Chapter 9 – Cellular Respiration:
Harvesting Chemical Energy
ENERGY AND METABOLISM RECAP
 Where does energy come from?
o
Autotrophs –
o
Heterotrophs –
Chapter 9 – Cellular Respiration:
Harvesting Chemical Energy

How do organisms store energy in the short
term and long term?
o
ATP –
o
Glucose –
o
Glycogen –
o
Starch –
ATP
(ya you know me…)
Where are the high
energy bonds?
Where do we get
the energy to make
those bonds?
Chapter 9 – Cellular Respiration:
Harvesting Chemical Energy
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Cellular Respiration
o
What is the difference
between catabolism and
anabolism?
o
What is the difference
between endergonic and
exergonic processes?
o
What is energy coupling, and
how does ATP play a role in it?
How do we get something to explode?
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Light it on fire!!! Blow it up!!! YA!!
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But what’s happening chemically?
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What gas has to be present in order
for something to blow up?
Cellular Respiration is the oxidation
or EXPLOSION of glucose 
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At the atomic level, oxidation deals
with transferring electrons…
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When you “oxidize” something, it
loses electrons
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Since the electrons carry energy,
the energy is transferred
Cellular Respiration is the oxidation
or EXPLOSION of glucose 
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So what happens to the substance
that lost the electrons?
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Since it gains the electrons (and
gets more negative) we say it gets
“reduced”
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Oxidation-Reduction reactions are
abbreviated “Redox”
Cellular Respiration is the oxidation
or EXPLOSION of glucose 
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How can you remember which
gains and which loses?
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OIL RIG
 Oxidation
Is Loss
 Reduction Is Gain
Cellular Respiration is the oxidation
or EXPLOSION of glucose 
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Let’s Model REDOX!!!
 REMEMBER
OIL RIG!!
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The orange balls represent electrons
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What happens when you LOSE an
electron?
What happens when you GAIN an
electron?
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How can we pass the energy across the
room without any of us moving??
Cellular Respiration is the oxidation
or EXPLOSION of glucose 
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This is how energy gets transferred
in cellular respiration!!
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Oxygen has a pretty high electron
affinity, so it’s at the end of the
chain
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So why do we need oxygen???
Chapter 9 – Cellular Respiration:
Harvesting Chemical Energy
CELLULAR RESPIRATION – BIG PICTURE
Who: which organisms do cellular respiration?
What: what are the general inputs and outputs of the process?
When: when did it evolve? When does it occur?
Where: where in the cell does it occur?
Why: why is it so important?
An Overview of Cellular Respiration
Details of ATP
Synthase
Chapter 9 – Cellular Respiration:
Harvesting Chemical Energy
HARVESTING ENERGY BY EXTRACTING ELECTRONS
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Energy based on electrons and their energy levels!!
o
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The more excited an electron is, the higher its energy level!
Electrons transferred = maintain energy if stays in same energy level
Redox reactions involve the transfer of electrons (REDOX)
o
Remember: OIL RIG
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partial redox!?- based on electron affinity (or the tendency of an atom to gain
electrons)
o
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Oxidation Is Loss (of electrons)
Reduction Is Gain (of electrons)
move from less electronegative molecule to a more electronegative molecule and
drop in energy level (slowly becoming oxidized from C-H bonds to “O bonds”)
NAD+ (a coenzyme, by the way)
o
o
NAD+ + 1e- + 1H = NADH
NADH will carry (or transfer!) these e- and p+ to the e- transport chain (ETC)
Chapter 9 – Cellular Respiration:
Harvesting Chemical Energy
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Using what we know…
 We
know cellular respiration makes ATP
 We
know it uses oxygen
 We’ll
start from the end and work
backwards…
Mitochondria
Let’s Model the ETC!!
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3 volunteers to be NAD+
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1 volunteer to be FAD
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3 volunteers to be the ETC pumps
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3 volunteers to hold the protons in the cristae
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1 volunteer to be ATP Synthase
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2 volunteers to be oxygen
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2 volunteers to ADP
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2 volunteers to be phosphate
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And… PHOSPHOLIPIDS!
Turn in lab/lab notebook to back
counter – if you don’t have it
today, turn it in late on Monday
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Take out your notes, diagrams, etc for CR
Video: Cellular Respiration
Starting from the Finish…
Cellular Respiration
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ATP Synthase is like a
motor – as it turns, it
attaches a phosphate to
ADP to make ATP
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How does it turn? (hint:
how does a wind mill or a
water mill turn?...)
H+
H+
H+

H+
H+
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Hydrogen ions (or H+) flow
through ATP Synthase,
turning it!
How do the hydrogen
ions get into the
cristae?...
Cellular Respiration
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REDOX!!
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OIL RIG

eH+ + e-
H+ + e-
Electrons are lost by one
substance and gained by
another
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Just like we passed the
electrons in class, electrons
are passed down the electron
transport chain
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But the electrons don’t travel
alone… they travel with a
proton… H+
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The electron is accepted by
the ETC and the proton (H +)
goes into the cristae
H+ + e-
Cellular Respiration
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Each oxygen at the end of
the electron transport
chain accepts 2 electrons
and 2 protons (H+) forming
water (a product of cellular
respiration!!)
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The buildup of the H+
inside the cristae can now
flow through ATP synthase,
bonding a P to the ADP
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Since this phosphorylation
of ADP to make ATP uses
oxygen, we call it oxidative
phoshporylation
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So where do the electrons
and protons come from??
H+
H+
O + 2 e- + 2 H+  H20
e- ee- e-
H+
+ +
HH
H+
H+
H+
Cellular Respiration
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NADH and FADH2 are the
proton/electron carriers!!
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When “unenergized” they
exist as NAD+ and FAD
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NAD+ picks up one electron
and proton and carries it to
the ETC
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FAD picks up two electrons
and protons and carries
them to the ETC
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So where do the FADH2
and NADH get their protons
and electrons?...
e- + H+
e- + H+
e- +
H+
Cellular Respiration

NADH and FADH2 are the
proton/electron carriers!!

When “unenergized” they
exist as NAD+ and FAD

NAD+ picks up one electron
and proton and carries it to
the ETC

FAD picks up two electrons
and protons and carries
them to the ETC

So where do the FADH2
and NADH get their protons
and electrons?...
e- + H+
e- + H+
e- +
H+

Let’s start
with
glucose…
Recap
2 ATP
Glucose
4 ATP
6C
Pyruvate
Glycolysis
Net: 2 ATP
2 NAD+
2 NADH + e-
3C
ETC
Pyruvate
3C
WhereCOdo the NADH
NAD+
and FAD
2 go???
2
NADH + e-
ETC
CoenzymeA
AcetylCoA
(Acetyl = 2 C)
ATP
2 CO2
Kreb’s
Cycle
NAD+
NADH + eNADH + eNADH + eFAD
FADH2 + e-
Proton Gradient = concentration of H+ higher inside membrane than outside
Chemiosmosis  flow of ions across membrane
Back for
more H+
and e-!!!
eNADH
NAD+
+ eH+
H+
+ e-
H+
NADH
NAD+
+ e- H+ + e-
FADH
FADH
2 + e-
H+ + e-
e- ee- e-
O + 2 e- + 2 H+  H20
H+
+ +
HH
H+
H+
H+
ATP
ADP + P
Which part of cellular
respiration requires
oxygen?
What do we call the
process of making ATP
from this step?
What do we call the
process of making ATP
without oxygen?
In which part does this
type of ATP formation
happen?
Which part of cellular
respiration requires
oxygen?
Glycolysis
ETC
What do we call the process
of making ATP from this
step?
Kreb’s Cycle
What do we call the process
of making ATP without
oxygen?
In which part does this type
of ATP formation happen?
Glycolysis
ETC
Kreb’s Cycle
So which parts of cellular
respiration require oxygen?
How much ATP can we get
without oxygen?
When there’s no oxygen…
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Which steps can we do
without oxygen?
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Which steps can’t we do?
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So… how much ATP can
we get with fermentation?
When there’s no oxygen…
2 ATP
Glucose
6C
Pyruvate
4 ATP
Net: 2 ATP
2 NAD+
2 NADH + e-
3C
ETC?
Pyruvate
3C
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NO! Because the ETC requires
oxygen to accept the electrons
from NADH and FADH2…
Fermentation
 NADH and FADH2 donate to alcohol in alcoholic
fermentation (yeast  bread, beer)
 NADH and FADH2 donate to lactic acid in lactic acid
fermentation (skeletal muscles… BURN!!!)
Regulation of Cellular Respiration
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Do we always need the same amount of ATP?
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When might we need more or less?
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What substances regulate the rates of reactions?
(hint: they’re proteins…)
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How do we regulate the action of enzymes?
Did-you-get-it Quiz
1.
2.
Which process or processes do you think the
“original anaerobic bacteria” used?
A. Glycolysis
B. Cellular respiration
C. Photosynthesis
Where specifically do the following take place?
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3.
Glycolysis
Kreb’s cycle
ETC
What are the roles of the following molecules in
cellular respiration?
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Glucose
NADH
O2
ATP Synthase
Recap – Key Terms and Ideas

What drives the
formation of ATP?

Where do the
electrons for the
ETC come from?

Where do the
proton pumps
(proteins that…
pump… protons)
get the energy to
pump protons from?

Why is the inner
membrane folded?
Manipulatives

You have yellow, orange, and blue papers
with the reactants, products, and processes
for cellular respiration

With your partner, match the processes with
their titles and products and put them in the
order they occur in cellular respriation
Glycolysis
Glucose hydrolyzed into two pyruvate
molecules
2 net ATP, NADH
Citric Acid Cycle or Kreb’s Cycle
Pyruvate loses CO2; remaining 2 C
molecule bonds with Coenzyme A
(CoA); electrons and H sequestered
by NADH
2 x NADH
Citric Acid Cycle or Kreb’s Cycle
AcetylCoA broken down further,
releasing two CO2 molecules;
electrons and H sequestered by NADH
and FADH2
2 x (3 NADH and 1 FADH2), 2 ATP
Electron Transport Chain
Inner membrane proteins reduced by
NADH and FADH2
Redox passage of electrons due to
difference in electron affinity
Electron Transport Chain
Oxygen reduced by electrons from
inner membrane proteins; binds with
2 protons and released as waste H2O
Reduction of oxygen
Chemiosmosis
Proton motive force/electrochemical
gradient/proton gradient drives
formation of ATP
HUGE production of ATP
Daily Grade Quizzie

Number a scrap piece of paper 1 – 20.

Yes, you may use your notes
2.
3.
1.
4.
5.
7.
6.
8.
9.
10.
11.
12.
13 – 18: write the letter of the steps below
for cellular respiration in correct order
Letter Process
Proton motive force/electrochemical gradient/proton
A
gradient drives formation of ATP
B
Inner membrane proteins reduced by NADH and FADH2
AcetylCoA broken down further, releasing two CO2 molecules;
C
electrons and H sequestered by NADH and FADH2
Oxygen reduced by electrons from inner membrane proteins;
D
binds with 2 protons and released as waste H2O
E
Glucose hydrolyzed into two pyruvate molecules
Pyruvate loses CO2; remaining 2 C molecule bonds with
F
Coenzyme A (CoA); electrons and H sequestered by NADH
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19. What is the purpose of cellular
respiration?

20. What is the purpose of photosynthesis?
2.
3.
1.
4.
5.
7.
6.
8.
9.
10.
11.
12.
13 – 18: write the letter of the steps below
for cellular respiration in correct order
Letter Process
Proton motive force/electrochemical gradient/proton
A
gradient drives formation of ATP
B
Inner membrane proteins reduced by NADH and FADH2
AcetylCoA broken down further, releasing two CO2 molecules;
C
electrons and H sequestered by NADH and FADH2
Oxygen reduced by electrons from inner membrane proteins;
D
binds with 2 protons and released as waste H2O
E
Glucose hydrolyzed into two pyruvate molecules
Pyruvate loses CO2; remaining 2 C molecule bonds with
F
Coenzyme A (CoA); electrons and H sequestered by NADH

19. What is the purpose of cellular
respiration?
 To

make ATP = energy for cellular work
20. What is the purpose of photosynthesis?
 To
store energy as food in glucose/to make
glucose from energy from sun
Write the number wrong on their paper
 Hand it back
 Each question is worth 5 pts (so -3 = 85%...)

Warm-up
1.
Where does photosynthesis take place?
2.
What are the reactants of photosynthesis?
3.
What are the products of photosynthesis?
4.
Why is photosynthesis evolutionarily a good thing?
5.
Do anabolic reactions require energy or release
energy?
Science Magic Trick
• Why do the chloroplasts glow?!
• It’s all about the electrons
Science Magic Trick
Science Magic Trick
Photosynthesis: what you didn’t
know you already knew…

What looks familiar in this diagram
of photosynthesis?

How are photosynthesis and
cellular respiration similar?

How are photosynthesis and
cellular respiration connected?
Photosynthesis: what you didn’t
know you already knew…

What’s the main purpose of photosynthesis?

What do we need to make glucose?
 CHO

Where will we get them?
 Electrons

(the things chemical bonds are made of…)
Where will we get them?
(remember: we’re building something [anabolic]
which requires energy)
 Energy
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Where will we get them?

Where does
photosynthesis
happen?
Warm-up
• Use the cards at your table to review the
steps in the light reactions and Calvin
cycle of photosynthesis
Light strikes PSII, exciting
electrons
PSII is oxidized
Light Reactions
Water is split by PSII, electrons
from water are gained by PSII
PSII is reduced
Light Reactions
Thylakoid membrane proteins
are reduced; protons are
pumped through the membrane
ETC proteins are reduced and a
proton gradient is generated
Light Reactions
NADP+ acquires H+ and e- from
NADP+ reductase in ETC
NADPH now carries H+ and e-
Light Reactions
Protons flow through ATP
Synthase
Chemiosmosis generates ATP
Light Reactions
Enzyme Rubisco attaches CO2 to
5C molecule (RuBP) to make
unstable 6C molecule, which
breaks down into 2 3C molecules
Carbon fixation
Calvin Cycle
ATP phosphorylates one 3C
molecule
Activation
Calvin Cycle
NADPH delivers H+ and e- to 3C
molecule making G3P
(glyceraldehyde-3-phosphate)
Reduction
Calvin Cycle
2 G3P molecules may be joined
to make glucose
Output
Calvin Cycle
OTHER 3C molecule regenerated
into RuBP (5C CO2 receptor)
Regeneration of RuBP
Calvin Cycle
Rubisco’s got a problem…
Problem:
• Rubisco can add
CO2 or O2
• Why is that bad?
• When stomata
(leaf holes) are
closed, O2 builds
up so Rubisco is
less efficient
• 2 solutions for
hot/dry weather:
C4 and CAM
CAM Plants
Summarize
• Using the diagrams, notes, and your
brains, write a summary about the
light reactions and Calvin cycle of
photosynthesis
• Include these in your summary: H2O,
O2, CO2, NADP+, NADPH, ADP, Pi,
ATP, G3P, glucose, Rubisco,
thylakoid, chlorophyll, stroma, light