Transcript CELLULAR RESPIRATION

Cellular Respiration
Spring 2013 - Althoff Reference: Mader & Windelspecht Ch. 8)
• Breakdown of glucose
• Glycolysis
• Inside the Mitochondria
• Fermentation
Lec
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Cellular Respiration
A _________ process that requires oxygen
and gives off carbon dioxide.
Most often it involves the ______________
_____________ of glucose
C6H1206 +6O2  6CO2 + 6H20 + ENERGY
CELLULAR RESPIRATION:
C6H12O6 is oxidized, O2 is reduced
Some key, basic facts…..
Glucose is a _______________ molecule
The breakdown products, CO2 and H20, are lowenergy molecules
• Facts 1 & 2 mean this is an ______________
process—a chemical reaction that releases
energy
• As noted in previous slide….
A) Glucose is oxidized (losses electron)
B) O2 is reduced (gains electron)
The slower this reaction (cellular respiration) the
more efficient the use of the glucose molecule
Expanding on  –slower is better
•
The cellular respiration “pathway” allows the
energy within a glucose molecule to be released
___________ so that the ATP can be produced
gradually.
•
If glucose molecule breakdown was all-at- once
then most energy released (in the form of heat)
would be lost
Slow “pathway” results in 36 or 38 ATP
molecules per glucose molecule or about ____
of the energy available in glucose.
•
NAD+ and FAD: Important _____________
•
•
_____ = nicotinamide adenine dinucleotide
_____ = flavin adenine dinucleotide
•
Part of NAD+ Cycle, a key _______ reaction in the
process of cellular respiration
Sometimes FAD subs for NAD+ in the cycle
•
•
Key here is that NAD+ accepts ____________ plus
a _______________ (H+) and NADH results
______ CYCLE
____________: “splitting sugar”
• Occurs _____________ the mitochrondria
• Does NOT require the presence of oxygen,
therefore glycolysis is ____________ (vs.
aerobic = O2 required)
• For all other phases of cellular respiration, the
“action” is __________ the mitochondria where
O2 is present and used.
The ______________ of Cellular Respiration...
Glucose is broken down in the cytoplasm to 2
molecules of pyruvate: GLYCOLYSIS
Pyruvate enters a mitochondrian (i.e., the
“______________________” of the cell) and is
oxidized, and NADH is formed. CO2, a _______
______, is removed. Cycle happens twice (2x) to
process pyruvate molecules: ________________
…phases 3 & 4 of Cellular Respiration...
Cyclical series of oxidation reactions in the matrix
of the mitochondrion result in NADH and FADH
(NAD+ cycle), _______________, and _________
__________. _______________producing total of
2 ATP molecules per glucose molecule ________
___________ (i.e., 2 x = 2 ATP)
Series of “carriers” inside the mitochrondrial
membrane move from one to the next electrons
that were removed from the glucose and pass
them until they are received by O2, that eventually
turns to water (H added). Result ___________.
Known as the __________________________
This is CELLULAR RESPIRATION
CYTOPLASMA
1
GLYCOLYSIS
Glucose  pyruvate
2
PREP
REACTION
3
CA
C
ELECTRON
TRANSPORT
CHAIN
4
MITOCHONDRION
___________________________
Glycolysis  PYRUVATE
• Pyruvate is a ________________ in cellular
respiration
• If O2 is not available to the cell, ______________
occurs in the cytoplasm leading to “some serious
consequences”…
• During fermentation, glucose is ______________
metabolized to lactate or to CO2 and alcohol (it is
species specific)…result can be net gain of only 2
ATP per molecule verses 32 – 34 under normal
cycle just described
GLYCOLYSIS: outside the mitochondria
• Again, process where glucose metabolized to 2
pyruvate molecules
• This process is _________________ found—in
other words, in all organisms regardless of domain
–suggest common “ancestry”.
• It occurs in the __________. Remember, Bacteria
& Archea (prokaryotic cell types) do not have
mitochondria. Because eukaryotic cells have
mitochondria, the citric acid cycle and electron
transport chain __________________
ADVANCEMENTS that result in more efficient
ATP production in this organelle type.
• Because in cytoplasma, may be why O2 not
required
Inside the Mitochondria - Summary
• Phases 2-4 occur __ mitochrondrion (not outside)
• Starts with pyruvate (which resulted from glycolysis breaking
down glucose molecule to 2 pyruvate molecules) being brought
in to this organelle
• Ends with ____ and ____ transported out to the
cytoplasm
• The CO2 _________ (i.e., no energy required) out of
the cell and into the bloodstream
• H20, a by-product of cellular respiration, can
a) ____ in the mitochondria, somewhere else
in the cell (cytoplasm), or
b)enter the blood stream and ________ by the
kidneys as needed.
Inside the Mitochondria – Details - A
• _____________________________ (so-named
because it occurs before the citric acid cycle). It
occurs in the ______ portion. Pyruvate goes to
2-carbon acetyl group attached to a coenzyme
(CoA) and CO2 is given off.
• ___________________________ takes place in
the _________ portion. Also known as Krebs
cycle (after ___________, 1930s). See inputs
and outputs of this phase in the next slide.
Inside the Mitochondria – Details - B
• ELECTRON TRANSPORT CHAIN – is a series
of ____________ that pass electrons (what
else?...dah) from one to the other. “These”
electrons brought in by NADH an FADH2
molecules. Turns into a series of ___________
_____________ reactions
• Most of the carriers are ________________ , a
____________ that is a tightly bound heme
group with central atom of iron.
Inside the Mitochondria – Details – B-1
• ELECTRON TRANSPORT CHAIN con’t–the
end of the chain is when O2 accepts the
electrons…therefore _____________ cellular
respiration because no ATP are produce.
• Cristae—has a special arrangement here to
allow pumping of ___ ions across the matrix to
intermembrane space (recall this is a
_______________ area = ________________)
• Here CHEMIOSMOSIS (ATD + P  ATP) takes
place
______________ and CHEMIOSMOSIS….
• Some ______________ poisons stop
CHEMIOSMOSIS
• Some “gum it up” by over-doing the H+ gradient
(i.e., over pump H+ across membrane)…others
reduce the pumping ability
• Either way, _____________________ is greatly
and immediately reduced….thus, cells ______! !
Other ATP facts
• Any point in time, only enough ATP available
collectively to sustain human life ___________
_______________.
• Mitochrondria produce approximately
___________________________ every day.
• _____________________. Muscle contractions
remain…thus, stiff. Will hold contraction for up
to 12 hours. Finally, things breakdown over 4860 hours.
Heads up exam question….
Read ECOLOGY FOCUS handout from
Mader (2007) to understand how carbon
monoxide poisoning “poisons”…..
Be prepared to answer what is going on at
the __________________ —can’t just say
the CO is bad for you!!
FERMENTATION
• It is an _______________ process.
1) anaerobic means _____ oxygen used
2) it is a ________ process
• Example: lots of anaerobic species of bacteria.
Many in your __________ (good thing—usually).
• Example: ___________ (cud-chewing animals)
rely largely on these anaerobic bacteria to
breakdown cell walls to obtain nutrient from
plants grazed/browsed. Thus,
________________…ruminating that is!
LACTIC ACID FERMATION
• Can provide a _____________of ATP (therefore
energy) initially…good example in muscles.
• ___________ lactate produced that is toxic to
cells…they can’t handle it. Main effect of the
_______ would be that it changes the ______
environment
•
• Muscles fatigue and cramp leading to
__________ debt. Key to “paying off” oxygen
debt is to get O2…that’s why you are still
breathing heavy _______ extensive exercise.
Make sure you know these
terms and where they “fit” in
• Pyruvate
Prep Reaction
Citric Acid Cycle
Glycolysis
• Electron Transport
Chain
• ATP
• Fermentation
• Anaerobic vs. Aerobic
• Cellular respiration =
1234
• Mitochondrion—what
happens “inside” and
“outside” during
cellular respiration
• Cristae
• Cytochrome
Electron transport
chain
THIS _____ CELLULAR RESPIRATION !!!!
___ ATP
___ ATP
________ATP