CELLULAR RESPIRATIONChapter 7
ORGANELLE OF FOCUS
OVERALL EQUATION
C6H12O6 + 6O2 6CO2 + 6H2O + energy(ATP)
Glucose + Oxygen Carbon Dioxide + Water + ATP
Adenosine triphosphate
VOCABULARY• Autotrophs • Organisms that are able to produce their own chemical
energy (food), ex. plants
• Heterotrophs– Organisms that obtain their chemical energy from other sources,
by eating ex. animals
• Cellular Respiration – Breaking down organic molecules to produce energy
• Aerobic Respiration – Oxygen present for pathway of breaking down food
• Anaerobic Respiration – No Oxygen present - causes an alternative pathway
Focus on Aerobic Pathway for Cellular Respiration
• STEPS– 1. Glycolysis – splits the glucose in half (6C to 3C),
occurs in cytoplasm of cell
– 2. Pyruvic acid conversion – loss of CO2 produces a product ready for the next step, occurs in mitochondria
– 3. Kreb Cycle – breaks down the remaining carbons from what’s left of the glucose molecule, produces high energy products NADH and FADH2, , occurs in matrix of mitochondria
Steps continued
-4. Electron Transport Chain – a series of proteins along the inner membrane of mitochondria that pass e-
* OXYGEN is the final acceptor of electrons
* H+ build up powers ATP synthase (sound familiar)
Glycolysishttp://instruct1.cit.cornell.edu/courses/biomi290/ASM/glycolysis.dcr
Pyruvic Acid Conversion
Why twice?
Kreb Cyclehttp://www2.nl.edu/jste/aerobic_respiration.htm
Where does CO2 go?
Where do NADH and FADH2 go?
Electron Transport Chain (ETC)http://highered.mcgraw-hill.com/sites/0072437316/student_view0/chapter9/animations.html#
Summary Chart
Step Input Output ATPGlycolysis Glucose 2 pyruvic
acids2 ATP
Pyruvic acid conversion
2 Pyruvic acids
2 CO2
2 Acetyl CoA0 ATP
Kreb Cycle 2 Acetyl CoA (1 per cycle)
4 CO2 2 ATP (1 made per cycle)
ETC O2
FADH2NADH
H2O 34 ATP
WHAT HAPPENS IF NO OXYGEN IS PRESENT??
Can’t do Electron Transport Chain so…no use doing Kreb cycle. Why not?
- NADH and FADH2 have nowhere to go if ETC not running.
ANAEROBIC PATHWAYS
• Alcohol Fermentation – organism produce alcohol from pyruvic acid ex. Yeast cells
• Lactic Acid Fermentation – muscle cells not receiving enough oxygen so they produce lactic acid from pyruvic acid
Alcohol FermentationHow many ATP?
2
Lactic Acid FermentationHow many ATP?
2
Pros and Cons of Lactic Acid Fermentation
• Pros – your muscle will keep working even without sufficient oxygen
• Cons – you feel it, lactic acid causes sore muscles and cramping
• Your body will get rid of lactic acid – it diffuses into blood and goes to liver where it is converted back to pyruvic acid – ready for O2
LIVER
RECAPC6H12O6 + 6O2 6CO2 + 6H2O + energy (ATP)
• GLUCOSE becomes…• CO2
• Oxygen is needed…• to accept the electrons at the end of ETC
• CO2 goes…• into blood, lungs, exhaled
• Water is produced when…• O2 collects enough e- and H+ to become water
• ATP is produced…• in glycolysis, Kreb Cycle and mainly in ETC due to
chemiosmosis
• Pyruvic acid is made …• at the end of glycolysis (3C)
• NADH and FADH2 carry …• Electrons and H+ to the ETC
• Protons (H+) build up in the …due to…• Intermembrane space, ETC pushing them out
• ATP synthase allows H+ to … and …• Back into the matrix, produces ATPs
• If no oxygen, yeast produce…• ethanol
• If no oxygen, muscle cells produce…• Lactic acid
• The ETC produces...• 34 ATPs
• In aerobic respiration, Pyruvic acid is converted to…
• Acetyl CoA
• The molecule that must be recycled in the Kreb cycle is…
• Oxaloacetic acid
• The break down of one glucose gives…• 38 total ATP
• Autotrophs…• Make their own food/chemical energy
• Heterotrophs…• Must eat other things to obtain chemical energy
• Aerobic respiration requires…• Oxygen
EAT AND BREATHE: IT’ GOOD FOR YOU!
The other half of the story=PHOTOSYNTHESIS
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