Download Cellular Respiration

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
Cellular Respiration Animations:
http://highered.mheducation.com/sites/9834092339/student_view0/chapter7/how_the_krebs_cycle_
works.html
http://highered.mheducation.com/sites/0072507470/student_view0/chapter25/animation__how_glyc
olysis_works.html
http://highered.mheducation.com/sites/9834092339/student_view0/chapter7/how_the_nad__works.
html
http://www.wiley.com/college/test/0471787159/biology_basics/animations/electronTransportChain.html
http://www.wiley.com/college/test/0471787159/biology_basics/animations/krebsCycle.html
http://highered.mheducation.com/sites/9834092339/student_view0/chapter7/electron_transport_sys
tem_and_atp_synthesis.html
http://highered.mheducation.com/sites/9834092339/student_view0/chapter7/electron_transport_sys
tem_and_formation_of_atp.html
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
Oxidation
C6H12O6 + 6O2 
glucose
6CO2 + 6H2O + energy
ATP
An Overview of Cellular Respiration
Reduction Reaction
• The gain of electrons to a
substance.
• Or loss of oxygen or gain of
hydrogen
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.
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 PGAL)
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
Synthase
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
What are the reactants required
in order for cellular respiration to
take place?
In what part of cells does
glycolysis take place? Where does
the Krebs Cycle take place?
How many ATP molecules (net) are
produced at the end of glycolysis?
Where are the proteins of the
electron transport chain located?
A) cytosol
B) mitochondrial outer membrane
C) mitochondrial inner membrane
D) mitochondrial intermembrane
space
E) mitochondrial matrix
The molecule that functions as the
reducing agent (electron donor) in a redox
or oxidation-reduction reaction
A) gains electrons and gains energy.
B) loses electrons and loses energy.
C) gains electrons and loses energy.
D) loses electrons and gains energy.
E) neither gains nor loses electrons, but
gains or loses energy
When a molecule of NAD+ (nicotinamide adenine
dinucleotide) gains a hydrogen atom (not a
hydrogen ion) the molecule becomes
A) hydrogenated.
B) oxidized.
C) reduced.
D) redoxed.
E) a reducing agent.
The ATP made during glycolysis is generated by
A) substrate-level phosphorylation.
B) electron transport.
C) photophosphorylation.
D) chemiosmosis.
E) oxidation of NADH to NAD+.
During glycolysis, when glucose is catabolized to
pyruvate, most of the energy of glucose is
A) transferred to ADP, forming ATP.
B) transferred directly to ATP.
C) retained in the pyruvate.
D) stored in the NADH produced.
E) used to phosphorylate fructose to form
fructose-6-phosphate.
Carbon dioxide (CO2) is released during which of
the following stages of cellular respiration?
A) glycolysis and the oxidation of pyruvate to
acetyl CoA
B) oxidation of pyruvate to acetyl CoA and the
citric acid cycle
C) the citric acid cycle and oxidative
phosphorylation
D) oxidative phosphorylation and fermentation
E) fermentation and glycolysis
During aerobic respiration, which of the
following directly donates electrons to the
electron transport chain at the lowest energy
level?
A) NAD+
B) NADH
C) ATP
D) ADP + Pi
E) FADH2
The direct energy source that drives ATP synthesis
during respiratory oxidative phosphorylation is
A) oxidation of glucose to CO2 and water.
B) the thermodynamically favorable flow of
electrons from NADH to the mitochondrial
electron transport carriers.
C) the final transfer of electrons to oxygen.
D) the difference in H+ concentrations on opposite
sides of the inner mitochondrial membrane.
E) the thermodynamically favorable transfer of
phosphate from glycolysis and the citric acid
cycle intermediate molecules of ADP.