Download Cellular Respiration - Esperanza High School

Cellular Respiration
Cellular Respiration
• A catabolic, exergonic, oxygen (O2)
requiring process that uses energy
extracted from macromolecules
(glucose) to produce energy (ATP)
and water (H2O).
C6H12O6 + 6O2  6CO2 + 6H2O + energy
glucose
ATP
Question:
• In what kinds of organisms
does cellular respiration
take place?
Plants, Animals, Protists,
Bacteria, and Fungi!!
• Ex: Plants - Autotrophs: selfproducers.
• Ex: Animals - Heterotrophs:
consumers.
Mitochondria
• Organelle where cellular
respiration takes place.
Outer
membrane
Inner
membrane
Inner
membrane space
Matrix
Cristae
Redox Reaction
• Transfer of one or more
electrons from one reactant
to another.
• Two types:
1. Oxidation
2. Reduction
Oxidation Reaction
• The loss of electrons from a
substance.
• Or the gain of oxygen.
Oxidatio
n
C6H12O6 + 6O2 
glucose
6CO2 + 6H2O + energy
ATP
Reduction Reaction
• The gain of electrons to a
substance.
• Or the loss of oxygen.
Reduction
C6H12O6 + 6O2 
glucose
6CO2 + 6H2O + energy
ATP
Breakdown of Cellular Respiration
• Four main parts (reactions).
1. Glycolysis (splitting of sugar)
a. cytosol, just outside of
mitochondria.
2. Grooming Phase
a. migration from cytosol to matrix.
Breakdown of Cellular Respiration
3. Krebs Cycle (Citric Acid Cycle)
a. mitochondrial matrix
4. Electron Transport Chain (ETC) and
Oxidative Phosphorylation
a. Also called Chemiosmosis
b. inner mitochondrial membrane.
An Overview of Cellular Respiration
1. Glycolysis
• Occurs in the cytosol just outside of
mitochondria.
• Two phases (10 steps):
A. Energy investment phase
a. Preparatory phase (first 5 steps).
B. Energy yielding phase
a. Energy payoff phase (second 5
steps).
1. Glycolysis
A. Energy Investment Phase:
Glucose (6C)
2ATP
C-C-C-C-C-C
2 ATP - used
0 ATP - produced
0 NADH - produced
2ADP + P
Glyceraldehyde phosphate (2 - 3C)
(G3P or GAP)
C-C-C
C-C-C
1. Glycolysis
B. Energy Yielding Phase
Glyceraldehyde phosphate (2 - 3C)
(G3P)
4ADP + P
4ATP
G3P
G3P
C-C-C C-C-C
0 ATP - used
4 ATP - produced
2 NADH - produced
Pyruvate (2 - 3C)
(PYR)
C-C-C C-C-C
(PYR) (PYR)
1. Glycolysis
• Total Net Yield
2 - 3C-Pyruvate (PYR)
2 - ATP (Substrate-level
Phosphorylation)
2 - NADH
The Energy Input and Output of Glycolysis
Substrate-Level Phosphorylation
• ATP is formed when an enzyme
transfers a phosphate group from a
substrate to ADP.
Enzyme
Example:
PEP to PYR
Substrate
(PEP)
Product
(Pyruvate)
OC=O
C-OCH2
OC=O
C=O
CH2
P
P
P
Adenosine
ADP
P P
P
Adenosine
ATP
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
Alcoholic Fermentation
• Plants and Fungibeer and wine
C
C
C
C
C
C
glucose
2ADP
+2 P
2ATP
2NADH
C
C
C
Glycolysis
2 NAD+
2NADH
2 Pyruvic
acid
2 NAD+
C
C
2 Ethanol
2CO2
released
Alcoholic Fermentation
2 Pyruvates + 2NADH + 2ATP 
2 Ethanols + 2 CO2 + 2 NAD+
Duff
Beer
Lactic Acid Fermentation
• Animals (pain in muscle after a
workout)
C
C
C
C
C
C
Glucose
2ADP
+2 P
2ATP
2NADH
C
C
C
Glycolysis
2 NAD+
2NADH
2 Pyruvic
acid
2 NAD+
C
C
C
2 Lactic
acid
Lactic Acid Fermentation
• End Products: Lactic acid fermentation
2 - ATP (substrate-level phosphorylation)
2 - Lactic Acids
2 – NAD+
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
2 CO2
C
C
C
Matrix
C-C
2 Pyruvate
2 NAD+
2NADH
2 Acetyl CoA
2. Grooming Phase
• End Products: grooming
phase
2 - NADH
2 - CO2
2- Acetyl CoA (2C)
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
3. Krebs Cycle (Citric Acid Cycle)
1 Acetyl CoA (2C)
OAA (4C)
Citrate (6C)
FADH2
Krebs
Cycle
2 CO2
(one turn)
3 NAD+
FAD
3 NADH
ATP
ADP + P
3. Krebs Cycle (Citric Acid Cycle)
2 Acetyl CoA (2C)
Citrate (6C)
OAA (4C)
2 FADH2
Krebs
Cycle
4 CO2
(two turns)
6 NAD+
2 FAD
6 NADH
2 ATP
2 ADP +
P
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
4. Electron Transport Chain (ETC) and
Oxidative Phosphorylation (Chemiosmosis)
• Location: inner mitochondrial
membrane.
• Uses ETC (cytochrome proteins) and
ATP Synthase (enzyme) to make ATP.
• ETC pumps H+ (protons) across
innermembrane (lowers pH in
innermembrane space).
Inner
Mitochondrial
Membrane
4. Electron Transport Chain (ETC) and
Oxidative Phosphorylation (Chemiosmosis)
• The H+ then move via diffusion (Proton
Motive Force) 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).
4.
Electron Transport Chain (ETC)
and
Oxidative Phosphorylation
(Chemiosmosis)
Outer
membrane
Inner
membrane
Inner
membrane space
Matrix
Cristae
Chemiosmosis Couples the Electron
Transport Chain to ATP Synthesis
Oxidative
phosphorylation.
electron transport
and chemiosmosis
Glycolysis
ATP
Inner
Mitochondrial
membrane
ATP
ATP
H+
H+
• Chemiosmosis and the electron
transport chain
H+
H+
Cyt c
Intermembrane
space
Protein complex
of electron
carners
Q
I
IV
III
ATP
synthase
II
Inner
mitochondrial
membrane
H2O
FADH2
FAD+
NADH+
2H
+
+ 1/
2 O2
NAD+
ADP +
(Carrying electrons
from, food)
Mitochondrial
matrix
Figure 9.15
ATP
Pi
H+
Electron transport chain
Electron transport and pumping of protons (H+),
which create an H+ gradient across the membrane
Chemiosmosis
ATP synthesis powered by the flow
Of H+ back across the membrane
Oxidative phosphorylation
4. ETC and Oxidative Phosphorylation
(Chemiosmosis for NADH)
higher H+
concentration
Intermembrane Space
1H+
E
2H+
3H+
T
C
NAD+
(Proton Pumping)
Matrix
ATP
Synthas
e
Inner
Mitochondrial
Membrane
O2 H O
2
2H+ + 1/2
NADH
+ H+
H+
ADP + P
H+
ATP
lower H+
concentration
4. ETC and Oxidative Phosphorylation
(Chemiosmosis for FADH2)
higher H+
concentration
Intermembrane Space
1H+
E
T
FADH2
+ H+
FAD+
(Proton Pumping)
Matrix
2H+
C
2H+ +
1/2O2
H+
ATP
Synthas
e
Inner
Mitochondrial
Membrane
H2O
ADP + P
H+
ATP
lower H+
concentration
TOTAL ATP YIELD
1. 04 ATP - substrate-level phosphorylation
2. 34 ATP - ETC & oxidative phosphorylation
18 ATP - converted from 6 NADH - Krebs
Cycle
38 ATP - TOTAL YIELD
ATP
Eukaryotes
(Have Membranes)
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
Maximum ATP Yield for Cellular
Respiration (Eukaryotes)
Glucose
Cytosol
Glycolysis
2 Acetyl CoA
2 Pyruvate
Mitochondria
Krebs
Cycle
2NADH
2 ATP
6NADH
2FADH2
(substrate-level
phosphorylation)
2NADH
ETC and Oxidative
Phosphorylation
2 ATP
(substrate-level
phosphorylation)
2ATP
4ATP 6ATP
18ATP
4ATP
36 ATP (maximum per glucose)
2ATP
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
2 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
Question:
• In addition to glucose, what
other various food molecules
are use in Cellular
Respiration?
Catabolism of Various
Food Molecules
• Other organic molecules used for
fuel.
1. Carbohydrates: polysaccharides
2. Fats: glycerol and fatty acids
3. Proteins: amino acids