Download Cellular Respiration

Glycolysis and
Cellular Respiration
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Section:
Slide # 2
Cells Need Energy
1. Organisms obtain energy
from food
2. Glucose is main source of
food for cells
3. Cells break chemical bonds
of glucose; energy released
4. Energy is stored in ATP
5. Making ATP is part of
cellular respiration
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Section:
Slide # 3
Cellular Respiration Equation
Cellular Respiration produces carbon dioxide
and water, which are used as starting materials
(reactants) in photosynthesis
Enzymes
C6H12O6 + 6 O2
6 CO2 + 6 H2O + 36 ATP
Reactants
Products
Slide # 4
Overview of Cellular Respiration
Pathways
Glucose
Glycolysis
Krebs
cycle
Fermentation
(without oxygen)
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Section:
Electron
transport
Alcohol or
lactic acid
Slide # 5
Glycolysis: Breaking
Sugar
1. Occurs in cytoplasm
2. Glucose (C6H12O6) is
broken down into 2
molecules of pyruvic acid
(C3H6O3)
3. Does not use oxygen
(anaerobic)
4. Net gain of 2 ATP’s
4 ATP produced
— 2 ATP consumed
2 ATP net gain
Also produces:
2 NADH
2 pyruvic acids
Glycolysis occurs in
prokaryotes & eukaryotes
An overview of the
process of glycolysis.
Cellular Respiration:
The Krebs Cycle &
Electron Transport
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Section:
Slide # 7
Cellular Respiration
1. Cellular respiration: process that releases energy
by breaking the chemical bonds of glucose in the
presence of oxygen.
a. Aerobic b/c it uses oxygen
b. Occurs in the mitochondria
c. Occurs in eukaryotic cells such as:
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Section:
Slide # 8
After Glycolysis: Cellular Respiration
1. About 90% of energy from glucose remains in pyruvic
acid
2. Purpose of the Krebs cycle:
a. Release the remaining energy & capture the highly
energized electrons by NAD+ & FAD (electron
carriers)
3. Produces CO2 as waste
cytoplasm
Slide # 9
The Breakdown of Pyruvic Acid
1. Pyruvic acid diffuses into
matrix of the mitochondria
2. Each pyruvic acid is
converted into acetyl-CoA
a. Produces 2 CO2
b. Produces 2 NADH
c. Transfers hydrogen
atoms & highly energized
electrons to NAD+ & FAD
Slide # 10
Results of the Krebs Cycle
Break down of Acetyl-CoA yields:
1 Acetyl-CoA
2 Acetyl-CoA
1 ATP
3 CO2
4 NADH
1 FADH2
2 ATP
6 CO2
8 NADH
2 FADH2
ATP and CO2 diffuse out of the mitochondria
NADH and FADH2 move to the cristae
Slide # 11
ETC: Oxidative Phosphorylation
1. Uses the H (carried by NADH
& FADH2) to build up a H+
gradient in the inner
membrane space to make 32
ATPs
2. Oxygen is consumed & water
produced
3. ADP is phosphorylated (to
ATP) in the presence of O2
Inner Membrane Space
Slide # 12
The Electron Transport Chain
1. The ETC is located on
inner membrane of the
mitochondria. (cristae)
2. Oxygen is final
acceptor of electrons.
3. Produces 32 ATP’s.
a. the most efficient form
of ATP production
Proton Gradient builds up
on one side of the
membrane
Slide # 13
The Electron Transport Chain
1. NADH & FADH2 carry pairs of electrons (from glycolysis
& Krebs cycle) to ETC.
2. As electrons are passed along ETC, the energy in the
electrons is used to pump H+ into inter membrane
space.
a. Creates a high concentration of H+ in
inter membrane space
b. H atoms diffuse back into core of mitochondria
through transport proteins (chemiosmosis)
c. Transport proteins use flow of H atoms to bond
last P onto ADP to create ATP (phosphorylation)
Fermentation: Anaerobic
My
muscles
are on fire!
1. Respiration that does not use O2
2. Releases net gain of 2ATP’s
3. Most of the energy from glucose remains in
the organic molecules (lactic acid or alcohol)
produced from fermentation.
Lactic Acid fermentation:
a. Glucose is broken down into lactic acid
b. Used to produce yogurt, buttermilk and sour cream
c. Occurs in muscle cells during intense exercise
d. Lactic acid causes muscle cells to BURN
Alcoholic fermentation: (Occurs in Yeast)
a. Glucose is broken down into alcohol & CO2
b. CO2 given off by yeast causes bread dough rise
c. Process is also used to make biofuels out of crop residue
Slide # 15
Sequence these
3
1
2
Oxidative phosphorylation
Glycolysis
Krebs cycle