Download Cell Respiration

Cell Respiration
Consumers/ Heterotrophs
• Autotrophs use sunlight to make ATP and Glucose
• Heterotrophs – get glucose from eating other
organisms and using it to make ATP.
Cell Respiration
• Cell Respiration-process by which the mitochondria break
down glucose to make ATP. (produces 36-38 ATP’s)
• Opposite of photosynthesis (ATP to Glucose)
Reaction
e-
e-
• 6 O2 + C6H12O6
• Occurs in 3 Stages
6 H2O + 6 CO2 + ATP
Mitochondria
• Stage 1 in the cytoplasm
• Stage 2 in the matrix
• Stage 3 in the inner membrane
cytoplasm
Glycolysis (stage 1)
All glucose molecules first go through glycolysis
– Anaerobic- no oxygen needed
– Occurs in the cytoplasm
– Produces:
-2 net ATP molecules
-2 NADH molecules
(electron carrier)
-2 Pyruvic Acid molecules
-Hydrogen is released
Glycolysis
1 Molecule of Glucose
2 Molecules of G3P
2 Molecules of Pyruvate
**
Gained 2 net ATP’s
Gained 2 NADH’s
Hydrogen is released
Citric Acid Cycle/ Krebs Cycle
-stage 2- Aerobic- requires oxygen
-occurs in the mitochondrial matrix
-a 3 carbon Pyruvate is converted into a molecule of 2
carbon acetyl-CoA.(CO2 is released)
- This happens twice because there are two Pyruvates
- 2 NADH’s are made
CoA = co-enzyme A
Citric Acid Cycle cont’d
-two Acetyl-CoA’s go through the citric acid cycle
- CO2 is released
- 6 molecules of NADH are
made
-2 molecule of FADH2 (e- carrier)
are made
-Yields 2 molecules of ATP
Hydrogen is released**
Electron Transport Chain
Stage 3, Oxidative Phosphorylation
-Aerobic- requires oxygen
-occurs in inner membrane.
-NADH delivers e-’s to the first protein in the ETC
-FADH2 delivers e-’s to the second protein in the ETC.
ETC Cont’d
• Each NADH yields about 3 ATP’s (give or take)
• Each FADH2 yields about 2 ATP’s (give or take)
• As electrons flow down the chain they cause
Hydrogens to get sucked out of the mitochondrial
matrix into the inner membrane space.
ETC Cont’d
+
• As the concentration of H ’s build up they are sucked
back into the mitochondrial matrix through ATP
synthase
• Oxygen is the final e- acceptor, it bonds with H+ to
make water (which is released)
• 32-34 ATP’s are produced**
Final ATP Count
Photosynthesis vs. Respiration
Fermentation
• Fermentation - anaerobic ATP production that occurs after
glycolosis when oxygen is not available. (not efficient , 2 ATP’s)
• Two Types
Lactic Acid Fermentation
• Lactic Acid Fermentation- produces 2 ATP’s and lactic
acid (lactate). The lactic acid is stored in muscles and
turned into pyruvate. (ex. when exercising)
Alcoholic Fermentation
• Alcoholic Fermentation- produces 2 ATP’s, CO2, and
ethyl alcohol. (ex. yeast)
Glucose
Glycolysis
2 ATP’s
no oxygen
Anaerobic
Fermentation
oxygen
Aerobic
Respiration
2 ATP’s
Kreb’s Cycle
(Citric Acid Cycle)
Lactic Acid
Fermentation
32 ATP’s
Alcoholic
Fermentation
Electron Transport
Chain
You should now be able to:
1. Explain in general terms how redox reactions
are involved in energy exchanges
2. Name the three stages of cellular respiration;
for each, state the region of the eukaryotic cell
where it occurs and the products that result
3. In general terms, explain the role of the
electron transport chain in cellular respiration
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
4. Explain where and how the respiratory
electron transport chain creates a proton
gradient
5. Distinguish between fermentation and
anaerobic respiration
6. Compare and contrast respiration and
photosynthesis in terms of location, reactants,
products, what is oxidized, what is reduced.
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings