requiring energy cellular respiration - mrs. kohout's...
TRANSCRIPT
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Cellular Respiration
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Cellular Respiration
A catabolic, exergonic, oxygen (O2) requiring process that uses energy extracted from macromolecules (glucose) to produce energy (ATP) and water (H2O).
Equation for CR?
C6H12O6 + 6O2 6CO2 + 6H2O + energy
glucose ATP
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Question:
In what kinds organisms does cellular respiration take place?
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Plants and Animals
Plants
Autotrophs: self-producers.
Animals
Heterotrophs: consumers.
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Mitochondria Organelle where cellular respiration takes
place.
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Redox Reaction
= Transfer of one or more electrons from one reactant to another.
Two types:
1. Oxidation
2. Reduction
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Oxidation Reaction
= The loss of electrons from a substance. (think backwards)
Or the gain of oxygen.
C6H12O6 + 6O2 6CO2 + 6H2O + energy
glucose ATP
Oxidation
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Reduction Reaction
The gain of electrons to a substance.
Or the loss of oxygen.
glucose ATP
C6H12O6 + 6O2 6CO2 + 6H2O + energy
Reduction
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Breakdown of Cellular Respiration
Four main parts (reactions).
1. Glycolysis (splitting of sugar) Glyco = sugar
Lysis = split
cytoplasm, just outside of mitochondria.
Glucose 2 molecules pyruvic acid
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Just so we’re on the same page…
What is NADH?
NAD is an electron carrier much like NADP+ (photosynthesis) Glycolysis gives off 4 electrons.
2NAD’s pick up the 4 e- (2 each) and become NADH.
NADH holds the electrons until they can be transferred to other molecules
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Breakdown of Cellular Respiration
2. Grooming Phase migration from cytosol to matrix.
3. Krebs Cycle (Citric Acid Cycle)
mitochondrial matrix
4. Electron Transport Chain (ETC) and Oxidative Phosphorylation a. Also called Chemiosmosis b. inner mitochondrial membrane.
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The breakdown
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1. Glycolysis
Occurs in the cytosol just outside of mitochondria.
Two phases
A. Energy investment phase
a. Preparatory phase (first steps). B. Energy yielding phase
a. Energy payoff phase (second steps).
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Glycolysis is an energy releasing reaction. Is energy necessary for glycolysis to start? Why? Need ATP to get things going.
Analogy –earn interest, must put in $ first
4 ATP are released in glycolysis for a net gain of 2 ATP – (“interest” is earned right away)
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1. Glycolysis
Total Net Yield
2 - 3C-Pyruvate (PYR)
2 - ATP (Substrate-level Phosphorylation)
2 - NADH
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3. Krebs Cycle (Citric Acid Cycle)
Location: mitochondrial matrix.
Acetyl CoA (2C) bonds to Oxalacetic acid (4C - OAA) to make Citrate (6C).
It takes 2 turns of the krebs cycle to oxidize 1 glucose molecule.
Mitochondrial
Matrix
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3. Krebs Cycle (Citric Acid Cycle)
Total net yield (2 turns of krebs cycle)
1. 2 - ATP (substrate-level phosphorylation)
2. 6 - NADH
3. 2 - FADH2
4. 4 - CO2
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4. Electron Transport Chain (ETC)
Location: inner mitochondrial membrane.
Uses ETC (proteins) and ATP Synthase (enzyme) to make ATP.
ETC pumps H+ (protons) across inner membrane (lowers pH in inner membrane space).
Inner
Mitochondrial
Membrane
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4. Electron Transport Chain (ETC)
The H+ then move via diffusion through ATP Synthase to make ATP.
All NADH and FADH2 converted to ATP during this stage of cellular respiration.
Each NADH converts to 3 ATP.
Each FADH2 converts to 2 ATP (enters the ETC at a lower level than NADH).
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That’s all for now….
Until we draw the cycles!!!
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1. Glycolysis
A. Energy Investment Phase:
Glucose (6C)
Glyceraldehyde phosphate (2 - 3C)
(G3P or GAP)
2 ATP - used
0 ATP - produced
0 NADH - produced
2ATP
2ADP + P
C-C-C-C-C-C
C-C-C C-C-C
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1. Glycolysis
B. Energy Yielding Phase
Glyceraldehyde phosphate (2 - 3C)
(G3P or GAP)
Pyruvate (2 - 3C)
(PYR)
0 ATP - used
4 ATP - produced
2 NADH - produced 4ATP
4ADP + P
C-C-C C-C-C
C-C-C C-C-C
GAP GAP
(PYR) (PYR)
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Substrate-Level Phosphorylation
ATP is formed when an enzyme transfers a phosphate group from a substrate to ADP. Enzyme
Substrate
O-
C=O
C-O-
CH2
P P P Adenosine
ADP (PEP)
Example:
PEP to PYR
P P P
ATP
O-
C=O
C=O
CH2
Product
(Pyruvate)
Adenosine
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2. Grooming Phase
End Products: grooming phase
2 - NADH
2 - CO2
2- Acetyl CoA (2C)
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3. Krebs Cycle (Citric Acid Cycle)
Krebs
Cycle
1 Acetyl CoA (2C)
3 NAD+
3 NADH
FAD
FADH2
ATP ADP + P
(one turn)
OAA (4C) Citrate (6C)
2 CO2
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3. Krebs Cycle (Citric Acid Cycle)
Krebs
Cycle
2 Acetyl CoA (2C)
6 NAD+
6 NADH
2 FAD
2 FADH2
2 ATP 2 ADP + P
(two turns)
OAA (4C) Citrate (6C)
4 CO2
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4. Electron Transport Chain (ETC) and Oxidative Phosphorylation (Chemiosmosis)
Inner
membrane
Outer
membrane
Inner
membrane space Matrix
Cristae
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4. ETC and Oxidative Phosphorylation
(Chemiosmosis for NADH)
NADH
+ H+
ATP
Synthas
e
1H+ 2H+ 3H+
higher H+
concentration
H+
ADP + ATP
lower H+
concentration
H+
(Proton Pumping)
P
E T C
NAD+
2H+ + 1/2O2 H2O
Intermembrane Space
Matrix
Inner
Mitochondrial
Membrane
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4. ETC and Oxidative Phosphorylation (Chemiosmosis for FADH2)
FADH2 + H+
ATP
Synthas
e
1H+ 2H+
higher H+
concentration
H+
ADP + ATP
lower H+
concentration
H+
(Proton Pumping)
P
E T C
FAD+ 2H+ +
1/2O2
H2O
Intermembrane Space
Matrix
Inner
Mitochondrial
Membrane
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TOTAL ATP YIELD
1. 04 ATP - substrate-level phosphorylation
2. 34 ATP - ETC & oxidative phosphorylation
38 ATP - TOTAL YIELD
ATP 32
Eukaryotes (Have Membranes)
Total ATP Yield
02 ATP - glycolysis (substrate-level phosphorylation)
04 ATP - converted from 2 NADH - glycolysis
06 ATP - converted from 2 NADH - grooming phase
02 ATP - Krebs cycle (substrate-level phosphorylation)
18 ATP - converted from 6 NADH - Krebs cycle
04 ATP - converted from 2 FADH2 - Krebs cycle
36 ATP - TOTAL
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Maximum ATP Yield for Cellular Respiration (Eukaryotes)
36 ATP (maximum per glucose)
Glucose
Glycolysis
2ATP 4ATP 6ATP 18ATP 4ATP 2ATP
2 ATP (substrate-level phosphorylation)
2NADH
2NADH
6NADH
Krebs
Cycle
2FADH2
2 ATP (substrate-level phosphorylation)
2 Pyruvate
2 Acetyl CoA
ETC and Oxidative
Phosphorylation
Cytosol
Mitochondria
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Fermentation
Occurs in cytosol when “NO Oxygen” is present (called anaerobic).
Remember: glycolysis is part of fermentation.
Two Types:
1. Alcohol Fermentation
2. Lactic Acid Fermentation
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Alcohol Fermentation
Plants and Fungi beer and wine
glucose
Glycolysis
C
C
C
C
C
C
C
C
C 2 Pyruvic
acid
2ATP 2ADP
+ 2
2NADH
P
2 NAD+
C
C
2 Ethanol 2CO2
released
2NADH 2 NAD+
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Alcohol Fermentation
End Products: Alcohol fermentation
2 - ATP (substrate-level phosphorylation)
2 - CO2
2 - Ethanol’s
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Lactic Acid Fermentation
Animals (pain in muscle after a workout).
2 Lactic
acid
2NADH 2 NAD+
C
C
C
Glucose
Glycolysis C
C
C
2 Pyruvic
acid
2ATP 2ADP
+ 2
2NADH
P
2 NAD+
C
C
C
C
C
C
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Lactic Acid Fermentation
End Products: Lactic acid fermentation
2 - ATP (substrate-level phosphorylation)
2 - Lactic Acids
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2. Grooming Phase
Occurs when Oxygen is present (aerobic).
2 Pyruvate (3C) molecules are transported through the mitochondria membrane to the matrix and is converted to 2 Acetyl CoA (2C) molecules.
Cytosol C
C
C 2 Pyruvate
2 CO2
2 Acetyl CoA C-C
2NADH 2 NAD+
Matrix
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Prokaryotes (Lack Membranes)
Total ATP Yield
02 ATP - glycolysis (substrate-level phosphorylation)
06 ATP - converted from 2 NADH - glycolysis
06 ATP - converted from 2 NADH - grooming phase
02 ATP - Krebs cycle (substrate-level phosphorylation)
18 ATP - converted from 6 NADH - Krebs cycle
04 ATP - converted from 2 FADH2 - Krebs cycle
38 ATP - TOTAL
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Question:
In addition to glucose, what other various food molecules are use in Cellular Respiration?
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Catabolism of Various Food Molecules
Other organic molecules used for fuel.
1. Carbohydrates: polysaccharides
2. Fats: glycerol’s and fatty acids
3. Proteins: amino acids
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