Cellular Respiration
What is Cellular Respiration?
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The process of converting ______________ found in nutrients (the food we eat) into a form
of energy that can be used by cells for various cellular functions
Cellular Respiration Equation:
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Sugar + Oxygen----------> Carbon Dioxide + Water + Energy
C6H12O6 + 6 O2  6 CO2 + 6 H2O + ATP
Redox Reactions
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Cellular Respiration involves a series of Redox (OXidation-REDuction)
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In REDOX reactions, electrons are _____________from one atom to another
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Oxidation is the ______ of an electron and a proton (H+)
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Reduction is the ______ of an electron and a proton (H+)
How Can We Remember?
OIL RIG
O____
R________
I_____
I____
L_____
G____
Adenosine triphosphate (ATP)
Sugar= Ribose
Adenine +Ribose+ 3 (tri) Phosphate Groups
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Cells use _________and REDOX reactions to transfer the energy found within large organic
molecules into a usable form of energy.
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This usable energy is stored in the form of ATP between the _________ bonds that connect
the phosphate groups
Mitochondria
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ATP is primarily produced in the __________
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Mitochondria are membrane-bound organelles, therefore they are found in BOTH
________ and animal cells
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The space enclosed by the inner membrane containing a mixture of enzymes, ribosomes
and _______________________
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____________________ or compartments formed by the inner membrane
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Inner membrane--- the inner most membrane that forms important invaginations
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Outer membrane---- Encloses the content of the mitochondria
How is ATP Produced?
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The breakdown of ___________produces ATP
Glucose + oxygen  carbon dioxide + water + ATP
_______________________________________________________
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This is an example of an _____________ reaction in which glucose is broken down
into CO2 and H2O
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1 glucose molecule (6 carbons) yields about 36 ATP
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__________________ reactions ABSORB energy from the surroundings
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__________________reactions RELEASE energy to the surroundings
3 Stages of Cellular Respiration
Stage 1: Glycolysis
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Glycolysis means “the __________ of sugars”
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This process takes place in the cytosol
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Can occur with or without the presence of oxygen
1 Glucose is “split” or broken down into 2 _____________
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C6H12O6  2 pyruvates
A pyruvate is a __ carbon molecule
But how does this all happen?
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2 ATP are ___________ and produce:
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4 ATP  final net of ___ ATP
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2 reduced NADH molecules
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NAD+ pair with 2 _________ e- and an H+ to yield NADH
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Super energy rich molecules to be used in further reactions
2 pyruvate molecules
In cells that use __________, the pyruvate is used in a second process, the Kreb’s cycle,
which produces more ATP.
When Oxygen is Absent
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By itself, glycolysis is somewhat inefficient because much of the cellular energy
remains in the two molecules of pyruvic acid that are created
Therefore, larger more complex organisms who need more ATP, utilize oxygen
and pyruvate molecules proceed further
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Alcohol Fermentation (Anaerobic)
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________ Acid Fermentation (Anaerobic)
When Oxygen is Present ----Formation of Acetyl Co-A
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From glycolysis, pyruvate is then pumped into the _____________
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Each 3 C pyruvate molecule is converted to a ___C molecule called _______ Co-A
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These 2 acetyl Co-A molecules are essential for the Kreb’s Cycle
Stage 2: The Krebs Cycle
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This cycle can only occur if oxygen is __________
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Takes place in the __________ of the mitochondria
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Each acetyl Co-A molecule proceeds through 1 turn of the Kreb’s Cycle, for a total of 2
turns per glucose molecule
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The product of 1 glucose molecule or 2 turns of the Kreb’s Cycle:
2 ATP
2 FADH2
8 _______
6 CO2
NADH/FADH----------> Co-enzymes that donate electrons to the Electron Transport Chain (ETC)
Stage 2: The Krebs Cycle
What are the products per glucose molecule or per 2 turns of the Kreb’s Cycle?
___ ATP
___ NADH
___ FADH2
___ CO2
What About NADH/FADH2?
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NADH and FADH2 are _____________required for cellular respiration to take place
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They shuttle electrons to the inner mitochondrial membrane
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NAD+ and _________  oxidized forms
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NADH and FADH2  reduced forms
Most of the energy extracted from glucose is in the form of the________________NADH and
FADH2
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They ___________ their electrons to the beginning of the electron transport chain
All 3 stages of cellular respiration must occur to produce the full 36 ATP
Stage 3: Electron Transport Chain (ETC)
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Coenzymes (electron carriers) ____________ between reduced and oxidized states as they
accept and donate electrons down the ETC
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______________are transferred from NADH to the first molecule in the ETC
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Electrons are passed __________ the ETC, molecule to molecule
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Until they combine with _____________ and H+ ions to form water
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Electrons travel down the ETC pulling _______ ions across the inner mitochondrial
membrane, creating a proton ___________
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Electrons are transferred to oxygen and water is formed as the product (2 H++ ½
O2H2O)
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The proton gradient powers ATP ____________
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Oxygen is known as the last electron acceptor
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The movement of H+ across the inner membrane causes a _______________ to form
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Charge separation A high [H+) in the inner membrane space versus the matrix
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Finally, ATP is synthesized via _________________phosphorylation driven chemiosmosis
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A molecular complex _______________ in the mitochondrial membrane
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The energy derived from the movement of protons is harnessed to ___________ ADPATP
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Oxidative phosphorylation generates a total of ______ ATP
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Note: You may hear these terms used as well
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__________________phosphorylation, instead of oxidative phosphorylation
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Electron transport ______________ (ETS), instead of electron transport chain (ETC)
*** These terms are used interchangeably
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The two ways atp can be formed
1. Substrate-level phosphorylation
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Generated during the ___________ and Kreb’s cycle
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Only a small amount of ATP is produced from these processes
2. Oxidative Phosphorylation
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Generated by the electron transport chain (or system)
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Generates the _________ ATP
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H+ ions leak back into the matrix (from the intermembrane space)
via ATP synthase