Cellular RespirationHarvesting Chemical Energy
ATP
Energy needs of life Animals are energy consumers
What do we need energy for? synthesis reproduction active transport movement temperature control
Where do we get energy? Energy is stored in organic molecules
carbohydrates, fats, proteins Animals eat these organic molecules food
digest food to get fuels for energy (ATP) raw materials for building more molecules
carbohydrates, fats, proteins, nucleic acids
ATP
What is energy in biology?
Whoa! Hot stuff!
Harvesting energy stored in food Cellular respiration
breaking down food to produce ATP in mitochondria using oxygen
formula shows glucose, but that is just an example could be other sugars, fats or proteins
glucose + oxygen carbon + water + energydioxide
C6H12O6 6O26CO2 6H2O ATP+ + + + heat
What do we need to make energy? The “Furnace”
mitochondria
Fuel food
carbohydrates, fats, proteins
The Helpers oxygen
“aerobic” enzymes
O2
food
ATP
Make ATP!Make ATP!
All I do all day…And no one
even notices!
CO2 + H2O + heatfuel
(carbohydrates)
O2
“Burn fuels” to make energycombustionmaking heat energy by burning fuels in one step
ATP
CO2 + H2O + ATP (+ heat)
respirationmaking ATP energy (& some heat) by burning fuels in many small steps
food(carbohydrates)
O2
Using ATP to do work?
A working muscle recycles over 10 million ATPs per second
Whoa! Pass me
the glucose& oxygen!
Can’t store ATP too unstableonly used in cell
that produces itonly short term
energy storage carbohydrates & fats
are long term energy storage
ATP
ADP + P
work
A Body’s Energy Budget
eatfood
synthesis
• resting energy• activity• temperature
control{• growth• reproduction{
storage• glycogen• fat{
ATP
What if oxygen is missing? Can’t complete aerobic respiration
alcohol fermentation yeast
glucose ATP + CO2+ alcohol
make beer, wine, bread
lactic acid fermentation bacteria, animals
glucose ATP + lactic acid make yogurt animals feel muscle fatigue
O2
but only make a little bit of ATP!but only make a little bit of ATP!
9-2 The Krebs Cycle and Electron Transport chain
WHAT HAPPENS DURING THE KREBS CYCLE?
Pyruvic acid is broken down into carbon dioxide in a series of energy-extracting reactions
The Krebs Cycle takes place in the mitochondrial matrix
Most of the chemical energy
gets transferred to electron
carriers NAD+ and FAD+
HOW ARE THE HIGH-ENERGY ELECTRONS USED BY THE ELECTRON TRANSPORT CHAIN?
The electron transport chain uses high-energy electrons from the Krebs Cycle to convert ADP to ATP
This stage takes place in the inner mitochondrial membrane
ATP
Any Questions??