Download Cellular Respiration - Franklin High School

Section 9-1
Journal
Feel the Burn
Do you like to run, bike, or swim?
These all are good ways to exercise.
When you exercise, your body uses
oxygen to get energy from glucose,
a six-carbon sugar
.
1. How does your body feel at the start of exercise, such as a long,
slow
run? How do you feel 1 minute into the run; 10 minutes into the
run?
2. What do you think is happening in your cells to cause the changes
in how you feel?
3. Think about running as fast as you can for 100 meters. Could you
keep up this pace for a much longer distance? Explain your answer.
Cellular Respiration
…Is the reason we breath
Oxygen in and
Carbon Dioxide out
The process of releasing the
energy from FOOD (glucose) to
make ATP= Cellular Respiration
How is this formula similar to
photosynthesis?
Reactants
C6H12O6 + 6O2
Products
6CO2 + 6H2O + Energy
Glucose
carbon
dioxide
oxygen
water
ATP, NADPH, FADH2
Net reaction shown above
A gradual release of energy from breaking down of glucose.
This happens when there is oxygen present.
If it released energy all at once all the energy would be lost as heat and light
Food (glucose) provides
1. Energy
2. Raw materials to build materials for growth
and reproduction
Glucose
Glycolysis
Krebs
cycle
Fermentation
(without oxygen)
Electron
transport
Alcohol or
lactic acid
Cellular Respiration
Glucose
(C6H1206)
+
Oxygen
(02)
Glycolysis
Krebs
Cycle
Electron
Transport
Chain
Carbon
Dioxide
(CO2)
+
Water
(H2O)
1st step Glycolysis (makes 2 ATP)
Glucose
breaks down into 2
Pyruvic acid
pyruvic acid
- No oxygen required for this step
- Occurs in cytoplasm of cell
- pyruvic acid moves into mitochondria
- Fast process, thousands in just a millisecond
- Also makes 2 NADH
Cellular Respiration continues
• …IF oxygen is present in cell (this is why we
must breath!)
• …continues to unlock energy not harvested in
glycolysis (90%) still there
• High energy electrons still in pyruvic acid will
be accepted by oxygen
Aerobic Respiration
Kreb’s cycle (citric acid cycle) + Electron Transport Chain
• requires oxygen
Kreb’s cycle (citric acid cycle)
makes 2 more ATP
• In mitochondria
• Pyruvic acid continues to break down
• Carbon atoms + oxygen
CO2(into air)
• ADP
• NAD+
• FAD
2 more ATP
NADH
FADH2
Citric Acid
Production
Electron transport chain
makes 32 more ATP
(similar to photosynthesis)
• High energy electrons move down electron
transport chain (proteins in mitochondrian inner
membranes)
• Those electrons help pump H+ out of matrix to
create concentration gradient
• Then H+ diffuses back in membranes and makes…
• ATP via ATPsnythase (enzyme)
• LOTS OF ATP GENERATED
• LOW energy electrons + H+ + Oxygen
H2 O
(waste)
Electron Transport Chain
Electron Transport
Hydrogen Ion Movement
Channel
ATP synthase
ATP Production
Total ATP production?
With oxygen
When one molecule of glucose breaks down…
2 glycolysis
2 Kreb’s
+ 32 Elec. Trans.
36 ATP from Cellular Respiration
38% efficient (better than standard car)
62% remaining, released as heat
Remember: oxygen present
Electrons carried in NADH
Electrons
carried in NADH
and FADH2
Pyruvic acid
Glucose
Glycolysis
Krebs
Cycle
Electron
Transport Chain
Mitochondrion
Cytoplasm
Anaerobic Respiration
- a different pathway
• Glycolysis still first (2ATP)
• If no oxygen available to cells
Anaerobic (w/o oxygen)
In plants: Alcoholic fermentation
Pyruvate + NADH
alcohol + CO2 + NAD+
In animals: Lacitc Acid Fermentation
Pyruvate + NADH
lactic acid + NAD+
(accumulates in muscles)
(sore muscles)
(only removed with oxygen)
(why we breath hard after race)
Compare
Aerobic respiration
Anaerobic respiration
Oxygen present
36 ATP total
Generates 18X more ATP
• No oxygen present
• Makes 2 ATP only
• Fermentation occurs
Our body uses both systems
Quick Energy
• Sprints
• 1st - uses small amts of ATP
produced previously
• Use reserves of ATP for few
seconds (50 meter dash)
• 2nd - ATP produced by lactic
acid fermentation
- up to 90 seconds (200-300
meters)
Get rid of lactic acid with oxygen
- breath harder after race
Long Term energy
• After 90 seconds the only
way to fuel activity is with
CELLULAR RESPRIRATION
Releases energy more slowly
than fermentation so must
pace yourself
Glycogen supplies in cell last
20-30 minutes
Then use Fat (good for weight
control)